Project Number: 42-MH-0248
The Upcoming Energy Crisis
An Interactive Qualifying Project Report
submitted to the Faculty
of the
WORCESTER POLYTECHNIC INSTITUTE
in partial fulfillment of the requirements for
Degree of Bachelor of Science
By
______Aaron M. Sikora
______Steven T. Ruo
______Jonathan W. Naumowicz
Date: April 29, 2003
Approved:
1. energy 2. wind 3. solar ______...... Professor Mayer Humi, Major Advisor Abstract
As we move into the 21st century, fossil fuel resources needed to produce electricity are diminishing rapidly. This project examines two renewable energy sources and outlines the rationale behind their inclusion into the United States Energy Policy. The project examines investments in both solar and wind energy to outline their benefits to society and their economic viability. Health benefits associated the two energy sources are also considered.
2 Executive Summary
This project was created to address the environmental, technological, and societal problems associated with the production of energy as we move into the 21st century. This project first outlines the history and technological innovation associated with wind and solar energy.
This explains how both energy sources came to be. It then explains how each energy source has grown and changed since their respective inceptions. Different technological innovations are discussed to show how wind and solar systems have become what they are today.
The project then examines how each of the energy sources works. The physical description of how solar panels work is examined first. This involves an in depth look at how photovoltaic cells take the energy associated with the light of the sun and turn them into usable energy. Next, the physical makings of the wind turbine are examined. The way in which wind is turned into energy via the rotor and blades attached to a turbine is discussed in detail. Different configurations are also discussed and an explanation as to why the current horizontal structure is used is also discussed.
Next, the project examines two energy farm models; a model using wind energy and the other using solar energy. The project then details the societal and economic competitiveness of each. Different scenarios are set up to showcase possible variations in the models.
The project then examines the current energy policy. The policy is then critiqued and modified with our suggestions for implementing solar and wind energy into the policy. The efficiencies behind each energy source are also discussed along with suggestions as to how research should focus on improving the efficiencies not only of current energy production, but also for fossil fuel consuming devices such as cars and planes.
3 The last section discussed are the social implications associated with the depleting fossil fuel reserves, the rising energy costs, and the failure to supply adequate amounts of energy to meet the demand. Health benefits and considerations are discussed and examined. The consequences of inaction are also discussed to help the reader better understand what might happen if nothing is done to curve the current problems faced dealing with the production of energy.
4 Table of Contents
1.0 INTRODUCTION ...... 6 2.0 HISTORY ...... 9 2.1 Solar Power...... 9
2.2 Wind Power ...... 23
3.0 PHENOMENOLOGY ...... 37 3.1 Solar Power...... 37
3.2 Wind Power ...... 55
4.0 MODELS ...... 67 4.1 Solar Power...... 67
4.2 Wind Power ...... 92
5.0 ENERGY POLICY...... 115 5.1 US National Energy Policy - Review ...... 115
5.2 Policy Implementation...... 119
5.3 Efficiencies ...... 136
6.0 SOCIAL IMPLICATIONS...... 145 6.1 Health Benefits ...... 145
6.2 Societal Consequences of Inaction ...... 149
7.0 CONCLUSION...... 153 8.0 BIBLIOGRAPHY...... 157
5 1.0 INTRODUCTION
This IQP deals with the eminent energy crisis in the United States. Current energy sources are not only expensive for the users, but their supply is limited and can generate significant environmental side effects. These side effects are growing worse with time and have begun causing serious socio-ecologic damage. We are going to analyze the present energy crisis and promote two alternative renewable energy sources. We will examine the economical and environmental benefits and detriments of wind and solar power. These energy sources are clean and through technological advances, they also have the versatility of being integrated into the
US’s energy grid. Our project will focus on creating a national energy plan that will entail replacing some current energy sources with alternative sources. We will try to determine what percentage of our nation’s energy can be generated by these alternative sources within twenty to thirty years.
Our motivations for working with this topic encompass a variety of aspects associated with alternative energy sources. Technological, environmental, and political problems all cause for difficulties in the implementation of these two sources of energy. The fact that there are side effects associated with standard energy usage such as acid rain and the depletion of the ozone layer, are visible and palpable in our lives. We will also examine how the efficiency of these sources has increased since their initial designs.
The reason that this project should be considered an IQP stems from multiple facts.
There exist both societal and technological problems, which result in the minimal usage of alternative energy sources that we see today. One issue is the financial difficulty associated with the funding of such projects. Investors are not willing to spend money on these sources of energy because of the degree of uncertainty associated with them. Most investors are already
6 profiting highly from their current energy sources such as petroleum, coal, and gas. They have no reason to risk an investment on an energy source with untested return values. Another major investor deterrent is the geographic limitations that exist for both sources. Solar and wind energy can only be harnessed in areas where they can effectively produce useable energy. One of our major project goals is to address these investor worries and demonstrate that the usage of renewable energy sources is safe, clean, and profitable.
In order for these renewable energy sources to be used on a large-scale basis, technological advances must be made. The efficiency of photovoltaic cells is very low. This makes it very difficult to justify the use of solar power on a community basis. Currently, the average maximum efficiency of these cells is approximately 26 percent. In order to reasonably implement the widespread use of solar power, we must master these new methods or find other ways to raise the efficiencies of solar power systems. The use of wind power faces a similar challenge. Wind turbine design is based on fundamental aerodynamic principals derived from airplanes. These principals work fairly well. Modern wind turbines, however, are inefficient at high wind speeds. If turbines could harness these high-speed winds more effectively without building a very expensive machine of course, then wind power would be more widely accepted for commercial use. Wind and solar power have experienced exponential growth and advance in the last 20-30 years, and we feel this trend will continue if the current effort in these fields is maintained. The trend could also increase rapidly if special focus was paid to developing a new energy program.
The initial and long-term costs of these systems are a concern when considering communal use of these energy sources. To install a modern wind turbine can cost anywhere from $150,000 US dollars to $500,000. The average maintenance costs of modern wind turbines
7 are around 1.5-2% of the initial cost. Though the initial cost of installing a turbine may be high, we feel the individual and societal long-term savings on energy expenditure as well as the low maintenance cost make the wind turbine an economically feasible system. Solar power systems for homeowners can cost anywhere between $25,000 and $60,000 US dollars depending on how large and how sophisticated the solar power system is. This price range is relatively affordable considering the long-term benefits of solar power systems. Solar panels only need the presence of sunlight to produce electricity and they can last on an average of 20 to 30 years without the need of any kind of maintenance. The initial cost of a solar power system is relatively inexpensive and can power almost a whole household requiring very little maintenance, which makes solar power another economically feasible system.
8
2.0 HISTORY
2.1 Solar Power
E Energy of the radiation h Planck’s constant µ Frequency of radiation
Solar power systems take the energy from the sun and change it into usable electricity.
This process is known as the “photovoltaic effect.”1 A scientist known as Edmond Becquerel
was the first to discover the photovoltaic effect in 1839. Since the day of its discovery, the
photovoltaic effect has been studied and tested for sixty years before this phenomenon could be
fully explained. The first solar cells were rated at an efficiency of 1% to 2% in the late 1800’s.
Today, the solar cells have greatly advanced since the late 1800’s utilizing different production
methods and materials in order to achieve higher efficiency ratings. A major problem with solar
power is its cost. Further research and development must still be done in order to bring solar
power into the market.2
Edmond Becquerel, a French experimental physicist, first discovered the photovoltaic
effect in 1839. At the age of 19, Edmond Becquerel noticed that certain materials would produce
small amounts of electric current when exposed to light. Becquerel noticed this effect when
experimenting with an electrolytic cell made up of two electrodes. When the electrolytic cell
1 “Turning Sunlight into Electricity: How it all Works.” National Center for Photovoltaics. 30 Oct. 2002
9 was illuminated, the conductance between the two electrodes increased. The fundamentals of the
photovoltaic effect were becoming realized and understood, but it was not until 1904 that this
phenomenon could finally be explained.3
The first sixty years or so in existence, the basic ideas behind the photovoltaic effect and
properties of Photovoltaic materials were being discovered. Willoughby Smith was the first to
discover the Photovoltaic effect in Selenium. The experiment was designed to test the very high
resistance of the Selenium bars that were provided to him. However, the results from the tests
showed great discrepancies indicating that there was another factor affecting the resistance of the
Selenium bars. With some experimentation, Willoughby Smith discovered that the presence of
light and light alone reduced the resistance of the Selenium bars.4 The discovery of the
photovoltaic effect in a material, Selenium, placed us on the road to the production of the first
William Grylls Adams, a professor of Natural Philosophy at King’s College in London,
with his student, Richard Evans Day, made one of the most important discoveries in the progress
of photovoltaics. Adams and Day discovered that illuminating the junction between Selenium
and Platinum also possessed the photovoltaic effect. The only difference was that the
Electromotive Force (EMF) in the junction of two materials was produced rather than altered as
was discovered by Becquerel.5 Werner von Siemens, a contemporary whose reputation in the
field of electricity ranked him along side Thomas Edison, calling the discovery “scientifically of
the most far-reaching importance.” The discovery made by Adams and his student, Day, proved
3 “A Walk Through the Time: The Story of Success.” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
10 that light could be changed into electricity through the material without the need for heat and/or
moving parts.6
The discoveries made by Becquerel, Adams, and Smith were the three most important
discoveries in the history of photovoltaics. Without these discoveries, solar power would not be
at the point it is today. Selenium has been proven to transfer light into electricity rather poorly
and would never be used in a modern solar cell, but it brought about the development of different
photovoltaic materials, which make up the highly reliable and efficient solar cells of today. Up
until 1904, nobody really understood why these materials would generate electricity from light.
Albert Einstein, the most famous scientist in the 20th century wrote a paper explaining this
phenomenon. Albert Einstein reasoned that light contains many particles called photons, which
have energy that is proportional to the frequency of the radiation. Einstein’s photoelectric
equation is now known universally as:
E = hµ
Where E is the energy of the radiation, h is Planck’s constant, and µ is the frequency of the
radiation. This formula indicates that light contains different levels of radiation for different
frequencies of light. This energy is absorbed by the materials such as Selenium and Platinum
and transfers it into an electrical current. Not many scientists at the time understood or agreed
with Einstein’s proposal until Robert A. Millikan experimentally proved it in 1916. Once
Einstein’s idea was accepted, he received the Nobel Prize in 1921 for his theoretical explanation
of the photovoltaic effect.7 Now that the photovoltaic effect was theoretically and experimentally explained, scientists could now focus on creating the world’s first solar cells.
6 Perlin, John. “Solar Evolution: The History of Solar Power.” California Solar Center. 07 Mar. 2003.
11 A Polish scientist, Czohralski, found a way to develop monocrystalline (single-
crystalline) silicon in 1918. This new method eventually helped scientists develop the first
monocrystalline solar cell in 1941. As the production methods for silicon cells were on the rise,
some scientists began looking at the photovoltaic effects in different materials. In 1932,
scientists discovered that cadmium-selenide (CdS) contains the photovoltaic effect and is still
one of the more important materials in solar cell production. Dr. Dan Trivich of Wayne State
University derived some theoretical calculations on some solar cell materials in order to
determine a way to compare different solar cells. From these calculations, Trivich was able to
develop a formula that would determine the efficiently of the solar cells.8 These methods and
theoretical calculations helped scientists create the first effective solar cells in the world.
In 1954, AT&T organized several demonstrations of solar cell functions. Gerald
Pearson, Daryl Chapin, and Calvin Fuller were the main discoverers of the silicon solar cell.
Silicon cells were the first solar cells to convert enough sunlight into electricity to power some
small electrical devices. Gerald Pearson, an empirical physicist at Bell Laboratories, stumbled
over a silicon solar cell that was far more efficient than the previously studied solar cell,
Selenium. Daryl Chapin and Calvin Fuller performed some experiments on the new solar cell
discovered by Gerald Pearson. Chapin and Fuller were eventually able to further develop
Pearson’s discovery into a solar cell that can convert enough sunlight into electricity in order to
power everyday electrical devices.9 Bell’s Laboratories recorded that the solar cells were
operating at efficiencies with 4.5%, but were soon increased to 6% within a few months.10 After
8 “A Walk Through the Time: The Story of Success” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
12 the early 1950’s solar power was well on it’s way to playing a major role in future technologies.
As soon after the first solar cells came out, their converting efficiency was increased within a
few months indicating the high potential of solar power.
The only problem with the new silicon solar cells developed by Pearson, Chapin, and
Fuller was the high cost per watt for the cell. The high costs unfortunately prevented solar power
from reaching the electrical market. A one-watt solar cell would cost $300/watt whereas a
commercial power plant would only cost 50 cents/watt to build in 1956. As a result, the only
demand for the newly invented silicon solar cells came for powering beach radios, propellers on
model planes, and miniature ships in pools. Solar power took a turn for the worse and appeared
to be a useless technology until the United States space program saved the technology from
disappearing.11
The Army and Air Force foresaw solar power as an excellent technology to use to power satellites that will orbit the world. However, as soon as the Navy was awarded the opportunity to
launch America’s first satellite into orbit, their primary power source was focused on chemical
batteries rather than solar power. The Navy saw solar power as an untried and very unsafe
technology to select until it was proven to be reliable and beneficial. Dr. Hans Ziegler, one of
the world’s foremost expert in satellite instrumentation in the late 1950’s, argued with the Navy
about the poor and misguided choice they were about to make by selecting chemical batteries as
their primary power source. Arguing that these chemical batteries would only last for only days
when a technology such as solar power can last for several years without the need for frequent
maintenance. The Navy compromised with Dr. Ziegler and implemented their new satellite, the
11 Perlin, John. “Solar Evolution: The History of Solar Power.” California Solar Center. 07 Mar. 2003.
13 Vanguard I, with a dual power system utilizing chemical batteries and solar power cells.12 The
Navy made a wise choice in implementing at least a good portion of the Vanguard I with solar cells because the chemical batteries ran out of power in almost a week. Due to the high reliability of the solar cells, the Vanguard I was able to communicate to the earth for several years.
In light of so much success regarding Vanguard I, many countries used solar power to power their satellites creating a solid demand for silicon solar cells. Soon after the launch of the
Vanguard I, America launched Explorer III, Explorer VI, Explorer VII and Vanguard II while the Russians launched their first satellite, Sputnik III. The most amazing out of the four satellites launched by America in the early 1960’s were Explorer VI. Explorer VI consisted of 9,600 solar cells, which was a much larger number of solar cells compared to previous satellites.13 Even
though the Vanguard I and many other American and Soviet satellites were successfully powered
by solar power in the 1950’s and 1960’s, many NASA officials doubted the technologies ability
in future space ventures. In fact, solar power was merely viewed as a hold over until nuclear
power systems became available. However, solar power technology was growing so fast that
solar engineers were designing larger and more power solar power systems proving those NASA
officials wrong. Solar power worked so well on Vanguard I that it lasted up to eight years
without any major malfunctions. As a result, nuclear power systems never made a huge advance
into the space program. Since the 1960’s, solar power remained the power system of choice for
the world’s satellites.14 The demand for silicon solar power technology was now there. The only
12 Perlin, John. “Solar Evolution: The History of Solar Power.” California Solar Center. 07 Mar. 2003.
14 thing NASA and other countries required was a company to produce these silicon solar cells for
their satellites. Companies like Hoffman Electronics took an interest in producing solar power
systems due to the growing demand for solar power in the space program.
Hoffman Electronics was the leading manufacturer for silicon solar power systems in the
1950’s and 1960’s. In 1955, a time when the demand for solar power systems was increasing,
Western Electric put commercial licenses for photovoltaic production for sale. Hoffman
Electronics was one of the companies that took advantage of the fresh solar power market. The
commercialization of solar power finally began in 1955, when Hoffman Electronics introduced a
14mW peak silicon solar cell for $25. The solar cell had an efficiency of 2% with the energy
costing approximately $1785 per Watt, an incredibly high price compared to modern solar power
systems, which range around $3 per Watt. The efficiencies of the first solar cells were low, but it
did not take long for the solar power industry to overcome this feet. In 1957, two years after
their first 2% efficiency model, Hoffman Electronics designed a solar cell with 8% efficiency and only a year later, introduced a solar cell with 9% efficiency. In two years, solar power showed a very large increase in the efficiencies of solar cells. Furthermore, in 1959, Hoffman
Electronics introduced a solar cell with efficiencies of up to 10% and 14% in 1960. In a matter of four years, solar cells made a huge advance, increasing their efficiencies by 700%.15 The
demand for solar cells was increasing in the early 1960’s due to the number of satellites being
sent up into space. As a result, more and more companies were eventually getting involved into
the solar power market. The age of solar power has now begun.
Now that solar power has been marked as one of the most dependable and advanced
technologies, the United Nations (UN) had a conference on solar energy applications in
15 “A Walk Through the Time: The Story of Success.” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
15 developing countries in 1961. Solar power has been expected to be a beneficial technology for
villages and secluded areas that are far away from the nearest utility grid. The cost to send
wiring from the grid to these secluded areas would be far more than the cost to implement a solar
power system that would power the entire village from sunlight alone. To discover better uses
and the appropriate direction for solar power, the Defense Studies Institute organized the first
few photovoltaic conferences in Washington, starting in the year of 1961. The uses of solar
power were taken further when Bell Laboratories developed the first commercial
telecommunications satellite, Telstar in 1962. The solar power system on the satellite was a
14W system jump-starting the telecommunications revolution, which made communicated
between long distances a much easier task.16
The only major issue with solar power was the incredible cost for the devices. The costs
would range near a couple hundred dollars per watt to thousands of dollars per watt. This was
never a large issue for the space program. The benefits from solar power far outweighed its
costs. The high reliability and almost infinite supply of energy allowed the satellites to last for
many years before any kind of maintenance was needed. The main concern for the space
program was size, efficiency, and durability with the cost per watt rendered insignificant. The
story is much different for solar power applications on Earth. The main concern is the cost per
kWh. On Earth, solar power is just another type of energy source so the cheapest energy source
is the best energy source. As it began to seem inconceivable to obtain solar power as a form of
energy source in any major applications on Earth, the cost per watt for solar power dropped to
approximately $20/watt. In the early 1970’s, Dr. Elliot Berman with the financial aid of the
Exxon Corporation developed these new, cheaper silicon solar cells. Dr. Berman realized that
16 “A Walk Through the Time: The Story of Success.” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
16 using poorer grades of silicon and cheaper packaging materials brought the price from $100/watt
to $20/watt, a significant decrease in price. Due to this recent discovery, solar power became an
economically beneficial power source for secluded areas that are far away from the power grids.
However, when other energy sources are near, solar power is still far too expensive to
implement. A good example of a beneficial solar power use is for offshore oilrigs. These rigs
require horns and lights to prevent ships from striking them. These devices used to be powered
by large, toxic, short-lived batteries. The costs to replace and install these batteries far
outweighed the cost to implement solar cells making solar power an economical choice.17 As solar power remains the most popular power source for the space program, the costs for solar power would further need to decrease in order for full-scale applications to be considered beneficial.
As the years pass, photovoltaic companies are still searching for newer and better ways to construct solar power systems. In 1963, the Sharp Corporation developed the first usable photovoltaic modules from silicon solar cells.18 Photovoltaic modules are a group of connected
solar cells in parallel and in series in order to meet specified output requirements. The
photovoltaic module is the key to designing solar power plants. The module ensures adequate
operating life and eliminates any possible electrical hazards. The largest photovoltaic module at
the time was a 242W module implemented in Japan. The United States constructed a 470W
photovoltaic field in the Nimbus space project in 1964.19 The construction of solar power plants
was on the rise, but the number of solar power plants would remain very small in number due to
17 Perlin, John. “Solar Evolution: The History of Solar Power.” California Solar Center. 07 Mar. 2003.
17 the costs. The costs for the silicon solar cells at the time were still too high for the demand for
solar power plants to skyrocket.
Despite the slow advancement of terrestrial applications, photovoltaic applications on
Earth were slowly but surely growing in number. The demand for terrestrial applications of solar power was still low, but the potential of solar power drove more and more companies into the market. In the early 1970’s, the Spire Corporation, Solar Power Corporation, Solec
International, Solar Technology International, and the Solarex Corporation were established.
The Spire Corporation was established by Roger Little in 1969 and is still one of the most important producers of solar cell equipment today. Between the years of 1970 and 1975, many different projects and companies from many different countries were formed during these years.
The French designed a CdS photovoltaic system that enabled educational T.V. broadcasting to the province of Niger in 1972. The Japanese formed the Sunshine project in 1974, which funded the research and development of photovoltaic systems. The United States government encouraged research in the field of photovoltaic systems for terrestrial applications in 1975.20
The countries that were involved in the research and development of photovoltaic systems were almost racing to see who could design the best and most efficient systems. Whether it was a race or not, the end goal was to bring economical photovoltaic systems to the surface of the planet.
In 1974 the railway industry took a turn to solar power. The Norfolk/Southern railway in
Rex, Georgia tested the ability of solar power to power their railway warning lights. The railway company was skeptical about the dependability of solar power so the warning lights were hooked up to the utility grid as a form of backup. It turned out that the winter was so bad that year that the backup power lines failed due to ice build up and the only thing powering the warning lights
20 “A Walk Through the Time: The Story of Success.” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
18 were the solar arrays. Since that year, Norfolk/Southern railway depended on solar power to
power the remaining warning lights and safety devices due to their low maintenance costs and
high dependability. Due to the success of solar power for Norfolk/Southern railway, many
railways around the world choose to follow their lead and implement their safety devices with
solar power as well.21 This trend would result in solar power powering many other small devices
around the world like streetlights and water pumps.
In the 1970’s, Dominique Compana, a graduate student in Paris, thought that pumping
water would make a good terrestrial application for solar power. The problem with some areas
in the world was that it was difficult to supply healthy water to areas without power. The Malian
government, a country located in Western Africa, was looking for something to save the country
from the worst drought in the 20th century. Father Verspieren, a French priest, was given the
task by the Malian government to seek out a way to acquire the water that runs underneath the
sand of the country. Father Verspieren brought back the idea of solar power water pumps and
initiated a solar water-pumping program. These highly reliable solar power water pumps
supplied Mali with the necessary water to survive saving Mali from inevitable disaster. Since
then, solar power has been an excellent power source for the people of Africa.22
The United States pushed hard for advancements in solar power. In 1977, LeRC, under the protection of NASA, experimented with various different photovoltaic applications. LeRC tested many different applications for solar power systems as well as implementing six meteorological stations in different locations in the United States. LeRC developed the first solar power module to power an entire village. The 3.5kW system was set up in an American
Indians reservation and was used for pumping water and supplying electricity to fifteen
21 Perlin, John. “Solar Evolution: The History of Solar Power.” California Solar Center. 07 Mar. 2003.
19 households.23 The application for solar power in areas far away from any power source became
an ideal application for solar power.
A power plant is a centralized power source that transmits its generated electricity to
consumers all over. However, from the 1960’s to the 1980’s there were billions of rural areas
that were not connected to the nearest centralized power source. The reason is that the cost to
connect the rural area to the electric grid was too high. As a result, these rural people have to
depend on kerosene lamps, automobile batteries, and generators to supply them with power.
These power sources are far too costly and inadequate. The implementation of solar cells in
these areas provided the people with higher quality and more reliable electricity. By the end of
the 1980’s, at least one hundred thousand families in Mexico, Central America, and the West
Indies used solar power as their power source. Solar power in rural areas and individual houses
that are far away from nearest energy grid became the ideal power source around the world.24
While solar power became the most beneficial option for rural areas, massive solar power plants
were still looming on the horizon.
With the huge push for advancements in solar power, the world began to produce
photovoltaic modules exceeding 500kW in 1979. In a manner of four years, photovoltaic
modules reached 1MW, 9.3MW, and in 1983, they reached 21.3MW. The introduction of larger
photovoltaic modules made the application of solar power plants more conceivable as they were
able to supply power to larger groups of people. ARCO Solar built a 6MW photovoltaic power
plant to be connected to the public electricity grid for the Pacific Gas and Electric Company in
California. The 6MW system powers 2,000 to 2,500 households depending on the demand at the
23 “A Walk Through the Time: The Story of Success.” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
20 time. ARCO Solar was just one of the first companies to implement a solar power plant that
added to the electric grid.25
The downside to large solar power plants is the large capital costs for land, transmission
lines, the foundation, support structures, and so on. Solar power systems are flexible in the sense
that they can be modified to fit any electrical need in any location as long as the sun is present.
In the late 1980’s, people came to realize that solar power modules could be implemented on the
rooftops of buildings. Marcus Real, a Swiss engineer, proved the economic advantages of this design by selling 333 of these rooftop solar power systems to the people in Zurich, Switzerland.
The success of the design lead to many governments all over the world developing incentives to encourage people to implement solar power systems on the roofs of their homes.26 The
advancement of solar power did not stop at power plants or even individual homes, but has been
applied to cars.
Volkswagen started the experimentation for solar cars with the implementation of 160W
solar power systems on the roof of cars for vehicle start up. In 1983, Solar Trek designed a
vehicle with a photovoltaic system of 1kW. The car drove 4,000km in twenty days with a
maximum speed of 72km/h (45mph) and an average speed of 24km/h (15mph). Under a year
later, the car surpassed the 4,000km between Long Beach, California and Daytona Beach,
Florida in eighteen days. The fact that a car can be run by solar power was a huge advancement
in itself. In 1987, a General Motors Sun racer vehicle achieved an average speed of 71km/h
25 “A Walk Through the Time: The Story of Success.” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
21 (44mph).27 Solar cars advanced significantly in a manner of four years but they would need a lot more work in order to be economical in the commercial world.
As more and more applications of solar power were being discovered each year, the advancements in the efficiencies and reduction in costs of solar panels did not stop after their discovery. In 1985, the University of New South Wales in Australia designed a solar cell that achieved efficiencies of up to 20%.28 Since then researches have studied the costs and
efficiencies for silicon solar cells in many different forms. Amorphous and thin-film
technologies for silicon solar cells have taken off in the 1990’s achieving higher efficiencies at
lower prices. A huge portion of the cost for solar cells is the way the cells are manufactured.
The main problem with solar power today is that its cost is higher than the cost for modern fossil
fuel power plants. Many believe that the current manufacturing methods: growing silicon in
cylinders or casting them as ingots and cutting them into very small pieces will never surpass the
costs of modern energy sources. Many companies around the world invest tons of money to
develop a silicon solar cell that will eliminate a majority of the manufacturing costs that brings
the price of silicon solar cells so high.29 Despite the constant search for a cost effective solar
cell, the price for solar cells will gradually reduce to the point where solar power will be
competitive in the energy market. The exact date of solar power becoming a major competitor in
the energy market is unknown, but the day it does looms closer and closer as each year passes.
Solar power currently costs too much to be competitive, but without the discovery of this
technology, society would not be at the point it is today. Without solar power, the space program
27 “A Walk Through the Time: The Story of Success.” 03 Sept. 2002. PV Resources. 04 Mar. 2003.
22 would be nowhere near as advanced as it is today and the telecommunication revolution would have never started and cell phones and satellite T.V. would still be just a dream. At this point in time, solar power is most beneficial in areas far away from utilities requiring quality and dependable energy sources powering small traffic lights and railway warnings to individual houses and to small villages. Solar power is a flexible energy source and can be applied to almost any situation requiring electricity. Even though the cost for implementing a solar power plant might seem too costly, there are many solar power plants that add to the electricity grids.
The only downfall to solar power is its high manufacturing costs. For solar power to become a competitive energy source, further research and development must be done to decrease the costs to produce solar cells.
2.2 Wind Power
The history associated with wind energy is a critical aspect of the current knowledge we possess about wind turbines and wind energy. The first solid evidence of using the wind to manufacture energy or useful results occurred in Persia around 500 A.D. The people there built windmills in order to grind grain and pump water. No specific diagrams or writings have been found to show exactly how the water pumping system worked. The grinding of grain, however, was quite simple. A grindstone would be attached to a vertical shaft in the middle of a small building. The vertical shaft was attached to the outside of the building where a giant fan like device. This device would turn when the wind currents going through it moved at fast enough speeds for it to be able to turn the vertical shaft that would then move the grindstone allowing for the grinding of the grain.
23 It is important to realize that initial wind usage was simple. Since electricity did not exist, the energy that was harnessed from the wind had to be translated directly into some type of direct action. At this point in time, there was no way to store the energy produced by the windmill. When windmills first appeared in Europe in the 13th century, they had been changed from the early vertical design of the Persians to a more drag efficient horizontal axis type design.
This design included a four-bladed mill that was attached to a central post. The central post was attached to a wooden “cog-and ring gears” arrangement that translated the horizontal motion generated by the mill into a vertical motion so that the grindstone could be turned in order to do its job. This movement from a vertical type axis to a horizontal axis was an extremely important one considering that the old vertical arrangements caused a loss of half of their rotor collection area due to shielding requirements. The idea of using a gear to translate horizontal motion into a usable vertical motion was developed by Vitruvius, which was initially invented to use with a water wheel type system. This occurred around the year 1270.
Later in history, around 1390, the tower design of this windmill was modified. Since the windmill’s primary function was still to grind grain, the tower itself became a factory of sorts, allowing for easy grinding, storing and processing of the grain product. The tower actually served as a living quarters for the people that worked there as well. The blades of the windmill itself used sails to generate aerodynamic lift. This again gave it an edge over its Persian mill counterpart by allowing for faster rotor speeds as well as more efficient grinding and pumping action of the grindstone itself.
The windmill sail itself underwent numerous changes for the next 500 years as scientists slowly and surely discovered the keys to an effective and efficient design. These keys are: “a camber along the leading edge, placements of the blade spar at the quarter chord position, center
24 of gravity at the same ¼ chord position and nonlinear twist of the blade from root to tip” (Drees,
1977). Although not limited to these features, most windmills did contain them in order to make
the most of the wind that powered them. Other designs included brakes, flaps and spoilers,
which were not as common as the options listed previously.
Other important innovations were demonstrated in the United States during the 19th century. The mills were redesigned to withstand high winds that could damage the structural integrity of the mill. This was accomplished by allowing for the blades to fold back like an umbrella of sorts to reduce the thrust associated with rotor capture. Perhaps the most important improvement in design was the change from sail type blades to steel blades in 1870. The steel blades were more easily moldable and were also lighter, allowing for a more efficient usage of the wind that pushed them. They turned so quickly, in fact, that a reduction gear had to be installed so that the new steel blades would turn at the required speeds associated with their tasks.30
Only in 1888, was wind utilized as an actual energy source. Up until this point in time,
the power generated from wind was simply used as a means of providing some type of service.
Services such the ones previously mentioned (grinding of grain and the pumping of water).
Charles F. Brush of the United States is credited with inventing the first large-scale device that
was used to produce electricity. The ingenuity behind Brush’s design was that it was the first
one to utilize a step-up gearbox that essentially allowed the wind to power a generator through a
50:1 ratio. This helped to turn to a direct current generator at its required speed of 500 RPM.
The problem with Brush’s windmill is that it could not generate nearly as much power as a
modern lift-type rotor of the same size. This was due to the design and technology limitations of
30 Dodge, Darrell M. WindPower – An Illustrated History of its Development. 19 Nov. 2002.
25 the time. Today’s rotors are able to produce about 70-100 kW where Brush’s design produced
merely 12 kW.
The next major design implementation associated with windmill design came from Poul
La Cour of Denmark in 1891. La Cour was the first scientist to integrate aerodynamic design to
the principles that of the blades on the rotor of the windmill. La Cour did this by using low-
solidity, four-bladed rotors incorporating primitive airfoil shapes. An airfoil shape is the shape
that the wing of a modern airplane utilizes to stabilize the airplane by modifying the lift and drag
associated with the configuration. Figure 2.2.1 illustrates the way that an airfoil design helps
generate the most efficient possible coefficient of lift while minimizing drag. (Of course drag would be increased when trying to slow down an object that uses a multi-bladed rotor.) The windmill contained a four-bladed rotor that was able to produce 25 kW. This of course was more power production than Brush’s design making it the leading design for windmill power generation at the time.
Figure 2.2.1 - This image illustrates how increased turning at the tail end of the object will increase the amount of lift that that object experiences. Employing this technology into the blade attached to the rotor of a windmill was a revolutionary concept at the time of La Cour. Today, this design is used on the wings of airplanes as well as the blades attached to the rotor of the wind turbine to help deal with and stabilize the lift and drag associated with airflow. http://www.grc.nasa.gov/WWW/K-12/airplane/shape.html
Unfortunately, both of the above designs were created at a time when they simply could not generate an adequate level of electricity. The cost for the energy was simply to great to even
26 foresee developing a series of either device to produce electricity. The aerodynamic principles applied by La Cour would be employed in new designs for years to come. In order to increase the amount of power that a specific wind turbine can produce, the rotor of that turbine must turn as quickly as possible. In order to get the most efficient usage of the wind that is powering the wind turbine, the lift of the blades on the rotor has to be maximized while minimizing the drag induced by the design. Finding a balance between these two factors has proved to be the most demanding scientific development associated with increasing the efficiency of wind turbines.
In the 1920’s, wind energy became a prominent power source in the midwestern states of the United States. By this time, the electric grids that existed in more urbanized areas of the country had not extended their reach to states such as Colorado and Kansas. The generators used in these areas were able to produce approximately 1 to 3 kW of energy. The machines were produced by an American company called Jacobs Wind Electric Company. It is important to realize that the systems that Jacobs produced were relatively expensive at the time; about $490 for a 32-volt system (2,500 watts). Not only did the user have to purchase the system, but they were also responsible for paying for the fifty-foot tower required to support the turbine. This was an additional $175. Lastly, the user had to pay for a lead-acid storage battery to keep the excess energy that the turbine generated for later use when winds were not as abundant. The battery cost was $365 making the total cost of the system around $1,030. On top of the basic expenses, users were also expected to do the wiring for usage of the electricity generated by the turbine on their own. It is easy to see that at this point in time, wind energy was not easily affordable and economically feasible to invest in. 31
31 Righter, Robert W. Wind Energy In America: A History. (Normon and London: University of Oklahoma Press, 1996). 97
27 For the fortunate farmers that were able to take advantage of systems such as the Jacob’s system, the unit was able to power a few household items that were helpful for living. Such items powered were refrigerators, washing machines, freezers, and power tools. Since the Great
Plains area of the United States typically had high winds year round and there was no other source for electricity, this made wind energy the ideal solution to the energy needs of those who could afford it. Other companies that produced wind powered units at the time were Miller
Airlite, Universal Aero-Electric, Paris-Dunn, Airline, Wind King, and Winpower. 32
Up until the 1930’s and 40’s, this was a vital source of energy for the people in the Great
Plains. During this time, however, new laws required that all houses in the United States have access to the national energy grid. This law was passed mostly because of the grim economic conditions the country faced during and directly following the Great Depression. It took a great deal of manpower to make power available to everyone. This helped to create new jobs as well as boost the economy. It can be argued that developments in modernization of society in general would have brought about these changes eventually. Once residents of these areas were effectively connected to the energy grid, wind energy was no longer needed to provide them with power. The high costs of wind energy as noted earlier in this section were no match for the low priced utilities that were offered by standard means such as oil and coal powered plants. This slowed the development of wind-powered turbines since there was no longer a significant need for them anywhere in the United States.
In some cases, wind power was not only usable on a small scale at this time, but also on a large scale. Most designs at this time were small because of the ease in producing and maintaining these machines. Larger machines were harder to construct and much more difficult to maintain. The technology available at the time limited the efficient production of power that
32 Ibid., 100.
28 could be generated by large devices. There were some successful advances, however. For instance, in Russia, in 1931, the Balaclava wind generator was able to produce 100 kW of power.
This experimental unit produced 200,000 kW of electricity in two years. An important aspect of this turbine was that it had the ability to translate electrical power from direct current (DC) into alternating current (AC). This was an important development because it would allow for future large-scale designs to integrate their power productivity directly into the electrical grid.
Unfortunately, technology still prevented large wind generators from being a practical source of energy due to the large costs that it took to maintain them. An attempt was made in the United
States in Vermont in 1941 at putting a large-scale wind generator into use. The rotor of the fan was constructed out of stainless steel. The diameter of the entire rotor was 175 feet. Due largely in part to the size of the blades as well as the material it was constructed out of, the experiment failed. After an intermediate period of time in which generator was online, one of the blades broke off due to a stretching of the metal that occurred. This proved what many scientists at the time thought was true; that the materials and technology available at the time were not advanced enough to allow for large-scale production of wind energy based off of large scale designed wind rotors. The actual strength properties of the materials available for use at the time in the construction of the blades of the wind turbine were what prevented their success.
During World War II in the late 1930s into the mid 1940s, the scientists in the world as a whole did not improve upon the different designs of the wind turbine. The funds and the resources needed for scientific improvements to wind turbines were all prioritized for the production of wartime goods. In some cases, countries such as Denmark were under direct control of their invading Nazi forces and were not able to function as effectively as when they
29 were independent. This lasted until 1945 when Germany surrendered to the Allies, ending the
war.33
After World War II, production of newly designed windmills continued. High fossil fuel prices assisted in pushing this development. Many countries in Europe simply wanted another way to produce energy to reduce the already have high costs they faced with cleaning up the destruction created by the war. In 1956-57, the 200 kW Gedser Mill wind turbine was created in
Denmark and operated up until the 1960’s when windmills again took the backseat to fossil fuel powered turbines. The machine featured a three-bladed rotor with an actual airframe connected to each of the blades to stabilize their motion. The pitch of the machines was fixed. This is because the machine was stall controlled. Meaning that, as the speed of the wind powering the machine increased, the machine would adjust itself to compensate for the stronger winds. The airframe attached to the blades on the machine would help to twist or “stall” the machine so that the turbulence from the higher winds would not damage or destroy the blades. This design was an incredible innovation for the time. Up until that point in time, any type of safety mechanism used with a windmill had to be activated by an actual person. This new design automated the process, expanding the lifetime of the blades that it was helping to protect.34
In 1973, the world had to deal with the “Arab Oil Crisis”. This created an increased need
for alternative energy sources. Again, wind power was considered for usage as a mainstream
source of energy for the electric grids of the United States and countries in Europe. The focus of
engineers and scientists was on large-scale wind turbines. It’s important to note that not all
development in the world was focused on large-scale wind harvesting, however. There were
33 Danish history (the s.c.nordic FAQ). 27 Oct. 1998. Danish History. 5 Nov. 2002
30 many innovations made in smaller turbines as well that helped decrease the average cost per
turbine.
Looking first at the United States, the energy crisis fueled the research and development
of several new wind turbine designs financed by the Federal government. There were designs
ranging from small, 1kW designs all the way up to 40kW designs. There were also larger
turbines developed. The two primary designs were Vertical Axis Wind Turbines (VAWT) and
Horizontal Axis Wind Turbines (HAWT). The largest designs were made under the HAWT
design structure and ranged from 100kW to about 3.2MW. These designs proved to be greatly
inefficient though because of their horizontal structuring. Most of the push in development was made for VAWTs, which ranged from 5kW to 500kW. The Energy Research and Development
Administration (ERDA) and the U.S. Department of Energy (DOE) were the two government entities that, respectively, organized the contracting and subcontracting of wind turbine development using Federal dollars. The research was done with the mindset that the only type of design that the government would consider using would be a multimegawatt turbine design that could help supply a substantial amount of energy to the electrical grid.
NASA also contributed a great deal of designs for wind turbines in the mid to late 1970’s.
Unfortunately, very little progress was made during this time due to mistakes in engineering design. NASA went back to the two-blade design that Ulrich Hutter had developed in Germany back in the 1960’s. This design used a two-blade design where a downwind rotor designed harnessed the power of the energy. A downwind rotor means that the rotor faces away from the wind in contrast to most designs before this time that faced into the wind. The crucial piece of engineering employed by Hutter that NASA failed to incorporate into their designs is what caused the complete lack of success and progress in their designs. “Teetering hubs” were used to
31 reduce the dynamic loads that two bladed configurations created in their shadows. Due largely to this lapse in design, NASA’s designs were largely unsuccessful. The MOD-0 and MOD-1 designs failed directly because of this design flaw. The rotors were not able to adjust to varying wind loads created by inconsistent wind speeds. Since millions of dollars were going into these machines, Congressional inquiries were held in order to find out why the turbine designs were making such small progress. Despite the newly designed MOD-2, which used an upwind, teetered hub on the rotor to account for any drag that may incur from the dead area between towers. Unfortunately, the negative sentiment surrounding the early NASA designs caused for its financial collapse. This occurred just as MOD-2 machine tests were providing the most beneficial information scientists had received yet from wind turbine study conducted by NASA.
Due largely in part to the Reagan Presidential administration of the 1980’s, most of the research done by the Federal government was abandoned. Funding for these programs was cut in order to reallocate the money and help pave the way for increased spending in military operations at that time.
Since most multi-megawatt designs had been unsuccessful to date, development as a whole shifted to smaller, more efficient designs. These designs, instead of working alone, were combined to create wind farms where vast arrays of wind turbines could be used in order to generate high volumes of electricity. The California Wind Rush is a great example of how this ideology exploded in the early to mid 1980’s. Danish engineers developed the Nordtank 55kW machine. The design, basically a sub design of the Gedser windmill, was well understood and relatively stable. Companies who were installing the wind farms were willing to go along with this design due largely to the failures of the current US designed small to medium wind turbine designs. Tests performed by the Danish test center at Riso gave evidence that the Danish designs
32 were indeed superior to that of their American counterparts. This was not true, and it was seen that the Danish designs were incredibly inefficient and suffered wear and tear after moderate periods of time. Costs to keep these machines working adequately negated much of the money they have saved in their production of energy. Federal energy credits are what empowered investors to purchase and support these machines. They knew that the government was the one backing up these investments, which over three or four years would pay back the entire investment. This does not even take into account the fact that the money made from selling the power generated by the wind turbines was distributed evenly as dividends to the investors. For instance, in 1983, a $100,000 investment would yield tax credits of $52,366 for the first year.
Over the first five years, taking into account depreciation, the investment would yield a ninety- percent return.35
Unfortunately for investors, poor designs caused many problems and breakdowns in the machines. Eventually, at the end of 1985, federal credits reimbursing those who purchased and installed these machines expired. There were many problems with the wind turbines, some unforeseen. The poor engineering of the towers holding the rotor caused for a breakdown in the material holding in intact over time. Besides poor engineering, scam artists also helped lead to the demise. Nine hundred turbines belonging to Micon all had to be shut down because the blades on the rotor were faulty. The financial, engineering, and scientific problems encountered by investors and energy companies alike signaled the end of the wind rush in California. In the beginning, the belief that designs of the time were well suited to handle the current energy needs seemed reasonable. By the end of the “rush” in 1984-85, many of the private investors who helped finance the wind turbines were lucky to come away with an even account. This is considering that the government credits associated with the installation and payments of the
35 Righter Wind Energy., 210.
33 machines did not cover the vast array of fixes that thousands of machines underwent as they broke down in the early 1980’s.
The majority of advancements in the late 1980’s and the early 90’s took place in Europe.
The efficiency of the turbines had not increased tremendously in the time period between 1980 until this time. The reason for development in Europe was due to ever increasing utility costs from conventional petroleum based power sources for countries on this continent. What makes wind power feasible is the price. Through innovation in design principles, prices per kWh produced by a wind turbine have dropped substantially since 1978. Darrell M. Dodge, a former employee of the U.S. Federal Wind Energy Program, writes:
The cost of energy from larger electrical output wind turbines used in utility- interconnected or wind farm applications has dropped from more than $1.00 per kilowatt- hour (kWh) in 1978 to under $0.05 per kWh in 1998, and is projected to plummet to $0.025 per kWh when new large wind plants come on line in 2001 and 2002. The hardware costs of these wind turbines have dropped below $800 per installed kilowatt in the past five years, under pricing the capital costs of almost every other type of power plant. 36
Cost benefits of wind power and comparisons to other sources of energy are examined in more depth elsewhere in this project.
The California wind rush was important because of the scientific results it fostered.
These results can be compared to current electricity production. We will examine the year 1988 based on the fact that this was after the “wind rush” that eventually weeded out unreliable wind energy production facilities. It also marks a good starting point for the growth that has occurred in California for wind energy over time. In 1988, the California Energy Commission reported that electrical output generated by wind turbines in the state was 1,824 GWh. This compared to the total energy consumption in that state for the year, which was 232,926 GWh, shows that wind generated a mere 0.7% of total electricity output in the state. Looking at the numbers for
36 Dodge. Windpower - History.
34 the year 2000, wind energy generated was 3,433 GWh. This compared to the total output of
280,496 GWh of electricity by all sources yields a percentage of 1.2 for the proportion of energy
in the state generated by wind.37 Since California is considered to be the leader in wind energy in the United States, these numbers give a clear indication that wind energy, as of the year 2000, was not producing a significant amount of energy for the state that relies on it the most. Looking at the United States as a whole in 1988, we can see that 1,540.7 billion kWh was produced in all sectors of electrical production. Wind energy production for that year was approximately 1.9 billion kWh. Comparing these two numbers and generating a percentage of total wind energy in the country for this year gives us a generation of 0.1 percent. This percentage increased to roughly 0.3 percent by the year 2000 showing that the progression of wind energy as a whole in the United States is not increasing significantly at all. 38
Looking at today’s costs for production of wind energy as compared to standard utilities
reveals promising numbers. In the United States for the first half of 2002, the average cost per
kWh of electricity produced was 7.06 cents per kWh. The average cost for producing a kWh of
energy with wind was about 5 cents per kWh in 1998. That figure is now estimated at 2.5 to 3
cents per kWh as of 2002.39 Of course, it is easy to see that producing wind energy is less
expensive than producing energy with conventional means such as oil and natural gas plants.
There are many more considerations in changing from these conventional sources to wind energy
despite the obvious financial and environmental benefits of such a change. A general list of
barriers are lobbyists in Washington D.C. that influence the energy prices in the United States
37 “1983-2001 California Electricity Generation.” California Energy Commission. 13 Nov. 2002.
35 based on a great deal of variables such as market availability of oil, gas, petroleum, etc. Also, the energy contracts that companies have signed with the state they produce power in, will continue producing them for years to come. Simply abandoning energy sources that have been used for years would not be easy. It is also important to consider that power produced by a petroleum based plant is much more stable than wind generated energy, which varies greatly as the speed of the wind powering turbines fluctuates over time. These concepts are driving innovation today.
36 3.0 PHENOMENOLOGY
3.1 Solar Power
c The speed of light Ef Electric field (V/cm)
Ep Energy of the photon f The fraction of which light is reflected of the surface of the semiconductor h Plank’s constant I Current (amperes) J Current density (A/cm2) k1 Extinction coefficient of the material (no sunlight) k2 Extinction coefficient of the material (sunlight) λ Wavelength n1 Real index of refraction (no sunlight) n2 Real index of refraction (sunlight) P Momentum R Resistance (ohms) σ Conductivity of the material (mho/cm) V Voltage (volts)
How Photovoltaic Systems Turn Light into Electricity
The process in which sunlight is turned into electricity is called the “photovoltaic effect.”
The great thing about solar energy is that it produces energy without exerting any form of noise or pollution or any kind of machinery. The phenomenon that occurs when light is converted into electricity occurs because of a special material called a semiconductor. Doping, a process that involves manufacturing impurities into semiconductors, helps the semiconductor turn light into electricity. Doping the semiconductor to create a P-type semiconductor and an N-type semiconductor allows us to create a p/n junction. When light strikes this p/n junction, the light
37 separates the electrons from its corresponding hole generating stored energy. This allows the
semiconductor material to carry current without the need for an external device to power it.40
All matter in existence is composed of atoms, which consist of protons, neutrons, and electrons. The protons are positively charged, the neutrons are neutrally charged, and the electrons are negatively charged.41 Electricity occurs when there is a flow of the negatively
charged electrons and/or positively charged holes. When a charge is applied to a material that
has free electrons in the conduction band and free holes in the valence band, electricity is the
result. Only certain types of materials have this ability.42
Every type of material in our planet falls into three different categories: conductors,
insulators, and semiconductors. Conductors have an excess of electrons allowing them to move
freely. This gives the conductive material the ability to maintain and carry an electrical current.
Conductors have a small band gap energy, which allows the electrons to reach the conductive
band rather easily. Insulators have the complete opposite effect and therefore, cannot maintain a
current. The band gap energy for insulators is very large compared to the band gap energy for
conductors. This makes it almost impossible for the insulator to carry a current. Semiconductors
fall into the conductive region between insulators and conductors. There are two types of
semiconductors out there: extrinsic and intrinsic semiconductors. The conductivity and
properties of intrinsic semiconductors occur naturally and cannot be altered. Where the
properties and conductivity of extrinsic semiconductors can be manufactured through a process
known as doping. This gives us control over the conductivity and properties of the
40 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995. 41 “Turning Sunlight into Electricity.” Nation Center for Photovoltaics. 20 Oct. 2002.
38 semiconductor. PV systems utilize these doped, extrinsic semiconductors to generate a more
efficient solar cell.43
There are many advantages to using semiconductors in photovoltaic cells, but there are
two in particular: its wide range in conductivity and its ability to carry current through positive
and negative charges. Ohms law helps to indicate the usefulness of semiconductors in
photovoltaics:
J = σ * Ef Equation 3.1.1
Where J is the current density (amperes per square centimeter), Ef is the electric field in
volts/centimeter, and σ is the conductivity of the material in mhos/centimeter.44 A mho is the
equivalent of 1/ohm, where an ohm is a term used to evaluate the resistance of a certain material.
As the resistance for a material increases at a constant voltage drop, the amount of current
flowing through that material decreases and vice versa. This comes from the relationship that is
also known as Ohm’s law:
V = I * R Eq. 3.1.2
Where V is the voltage in volts, I is the current in amperes, and R is the resistance in ohms. The
conductivity can be determined by the reciprocal of the resistance. For example, if the resistance
of a material is greater than 1,000 ohms, then the conductivity will be less than 1,000 mhos. A
higher conductivity will result in a lower resistance. Conductors have a conductivity of 106
mhos/cm, which means that the resistance of a conductor is approximately 10-6 ohms/cm, a very
small resistance.45 For example, the voltage drop over the conductive material in one centimeter is 10 volts. Using ohms law, we are able to determine the amount of current that can flow through the conductor in one centimeter:
43 Sayigh, A.A.M., ed. Solar Energy Engineering. New York: Academic Press, 1977. 44 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995. 45 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995.
39 V = I * R
I = V / R
I = 10 / 10-6 = 106 amperes
With the voltage at 10V, the amount of current that can flow through a conductor for a given centimeter is 106A, which is a very high amount of current. This demonstrates how useful conductors are in their ability to carry current. Insulators on the other hand, have a conductivity of 10-11 mhos/cm, resulting in a resistance that is equivalent to 1011 ohms/cm.46 Using ohms law at a voltage drop of 10 volts, we can determine the amount of current that can flow through an insulator in one centimeter:
I = V / R
I = 10 / 106 = 10-6 amperes
At a 10V voltage drop, an insulator can carry a current of 10-6 amperes, which is a very small
amount of current. This indicates how useless insulators are in their ability to carry current. A
conductor has the greatest potential to carry current, where an insulator has the least potential to
carry current. A semiconductor can lie in the range of 10-6 to 104 mho/cm depending on the
properties that we impinge on the extrinsic semiconductor. This range allows us to have
complete control over the conductivity of the material that we use. For example, we can alter the
conductivity for Silicon by a magnitude of 1/1000 to 1000 mho/cm through different types of
manufacturing methods to fit our needs. This gives us a good amount of flexibility in the
development of PV systems. The other benefit of using a semiconductor is that the negatively
charged electrons and/or the positively charged holes can carry the electrical current. This
benefit is what makes the semiconductor so useful in PV systems.47
46 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995. 47 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995.
40 There are two different bands that an electron for a semiconductor can be in: the conduction band or the valence band. The electron starts off in the valence band. The valence band is initially full with all the electrons that the material contains.48 When the temperature of the semiconductor increases, some electrons will acquire enough thermal energy to leave the valence band and enter the conduction band. When this occurs, the conduction band can play a part in the current flow. The fleeing electron leaves behind a positively charged hole in the valence band, which indicates a missing electron. When this occurs, the valence band is no longer full and can also play a role in the current flow. This process describes how PV systems work. However, PV systems utilize the energy from sunlight by using an electrical field to help excite the electron and send it into the conduction band more efficiently.49
An electric field can be created through a process known as doping. The electric field is used to send the electrons into the conduction band more efficiently resulting in a higher current flow potential. This process involves manufacturing the semiconductor material with impurities.
There are many different techniques utilized to impose an impurity on the semiconductor. Every technique has its own unique effect on the performance of the PV cell and the impurity concentration of the semiconductor. Typically, the impurities are generated by imposing different impurity atoms onto the semiconductor, the impurity atoms replace the semiconductor atoms at the lattice points of its crystal structure giving the semiconductor an excess of electrons or an excess of holes.50 The resulting semiconductor is either a donor or an acceptor. A donor will have an excess of electrons, where an acceptor will have an excess of holes. By placing a
48 Sayigh, A.A.M., ed. Solar Energy Engineering. New York: Academic Press, 1977. 49 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995. 50 Sayigh, A.A.M., ed. Solar Energy Engineering. New York: Academic Press, 1977.
41 donor right next to an acceptor, the result is an electric field.51 The electric field helps send the
electrons into the conduction band increasing the amount of current that the semiconductor can
carry. Every Pure Silicon host atom has four-valence band electrons covalently bonded with
neighboring atoms. The group number for an element can stand for the number of valence band
electrons for the element. For example, a group II element has two valence band electrons and a
group VI element has six valence band electrons. The introduction of a Group V impurity atom
from the periodic table to Silicon, which is from Group IV, will result in an excess electron
making the doped atom a donor. The introduction of a Group III atom to Silicon will result in an
excess hole making the doped atom an acceptor. Not all semiconductors are from Group IV, so
if we choose a Group III semiconductor atom, then the donor will be from a Group IV atom and
the acceptor will come from a Group II atom. However, the most abundant resource and most
commonly used semiconductors today are known as Silicon.52
Pure Silicon is a Group IV semiconductor, so the semiconductor will be doped with a
Group V element and a Group III element. The Group V Phosphorous element will be used to
dope the Silicon creating a donor. The resulting silicon is known as N-type silicon (N standing
for negative). The Group III Boron element will be used to dope the Silicon creating an
acceptor. The resulting silicon is known as P-type silicon (P standing for positive). The amazing
part of this design occurs when placing P-type silicon right next to N-type silicon, which is
called a p/n junction. The result is the formation of an electric field between the N-type and P- type silicon. This electric field plays a very important role in the semiconductor’s ability to carry current.53
51 “Turning Sunlight into Electricity.” Nation Center for Photovoltaics. 20 Oct. 2002.
42 The temperature and concentration of impurity atoms on the semiconductor play a direct role in how well a PV cell can carry current. The electron mobility for Si, GaAS, CdTe, CdSe, and GaP semiconductors is shown below as a function of temperature.
Electron Mobility for Different Semiconductor Materials - 9000 8000 Si 7000 6000 GaAs 5000 CdTe 4000 second) CdSe 3000 2000 GaP 1000
Electron Mobility (cm^2/volt 0 27 127 227 Temperature (Celsius)
Figure 3.1.1
The higher the electron mobility, the more current the semiconductor can carry. The temperature variable ranges from just above room temperature to a scorching 227˚C. As the figure above indicates, the electron mobility is much higher at room temperature than at higher temperatures.
These values will change depending on the process chosen for doping the semiconductor, but the overall curve will remain the same. Figures 3.1.2 and 3.1.3 show the electron and hole mobility for different semiconductors at 27˚C as a function of impurity concentration.
43 Electron Mobility as a Function of Impurity Concentration t 8000 7000 Ge 6000 Si 5000 4000 GaAs
second) 3000 CdTe 2000 CdSe 1000
Electron Mobility (cm^2/vol 0 1E+14 1E+16 1E+18 Impurity Concentration (cm^-3)
Figure 3.1.2
Hole Mobility as a Function of Impurity Concentration - 2000
1500 Ge Si 1000 GaAs second) 500 CdTe
0 Hole Mobility (cm^2/volt 1E+14 1E+16 1E+18 Impurity Concentration (cm^-3)
Figure 3.1.3
Both figures 3.1.2 and 3.1.3 indicate that at higher impurity concentrations, the hole and electron mobility of the different semiconductors decreases. The semiconductor's ability to carry a current decreases if the temperature and the impurity concentrations get too high. Each semiconductor has a different hole and electron mobility indicating uniqueness between different semiconductor materials. As a result, each semiconductor has its own advantages and disadvantages.54
54 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995.
44 From the graphs above, Gallium Arsenic appears to perform the best out of all of the
other semiconductors and is a well-developed technology, but it is very expensive to make,
making the use of this semiconductor unattractive. Germanium is also a well-developed
semiconductor technology, but its energy gap is too small. CdTe is made from scarce material
and CdSe has a long lifetime, but it is expensive making these semiconductors an unattractive
choice. Silicon does not perform the best out of these different semiconductors, but it has a
value that is close to the maximum potential power of a semiconductor, it is the cheapest, and it
is most abundant semiconductor. As a result it is the most commonly used semiconductor
today.55
We need to utilize an electric field because of a process known as recombination.
Recombination occurs when the energy and momentum transferred to the electron is not enough
to keep the electron and hole pair from recombining. The bad thing about recombination is that
once the electron and hole pair recombines, the pair cannot be used to add to the generated
current. The electric field acts as a separator keeping the electron and its corresponding hole
apart so the conduction band and the valence band can be used to carry more current more
effectively. The electric field greatly reduces the chance for recombination making the electric
field an essential part to the functionality of PV cells.56
The formation of an electric field occurs when P-type semiconductor material is placed
right next to N-type semiconductor material.57 The concentration of holes in the P-type silicon
and electrons in the N-type silicon are high. The electrons in the P-type Silicon that are close to
the p/n junction will move toward the N-type region because the N-type region has a lower
55 Ibid. 56 Sayigh, A.A.M., ed. Solar Energy Engineering. New York: Academic Press, 1977. 57 “Turning Sunlight into Electricity.” Nation Center for Photovoltaics. 20 Oct. 2002.
45 electron energy, which will attract electrons. In the same manner as the electrons, the holes in
the N-type Silicon near the p/n junction will move toward the P-type region because the P-type
region has a lower hole energy, which will attract holes. Almost instantly, the positively charged
holes and negatively charged electrons redistribute creating some form of equilibrium. The
result is the formation of an electric field at the p/n junction, which acts much like a barrier
separating the P-type silicon from the N-type silicon.58
This electric field or barrier makes it difficult for the electrons from the N-type silicon to
move over to the P-type silicon. This is due to the substantial amount of electrons in the N-type
material and holes in the P-type material. This uneven distribution of the electrons and holes in
the two different materials causes the electric field to have the characteristics of a diode. This
means that the electric field acts like a one-way road, allowing electrons to only flow from the P-
type silicon to the N-type silicon and the holes to flow only from the N-type silicon to the P-type
silicon. Due to the equilibrium of the electric field, no current will flow without the help of an
external energy source applied to the semiconductor.59 In the case of solar energy, the external
energy source comes from the photons in sunlight.
Sunlight provides the Earth with tons and tons of energy in the form of energy particles
known as photons.60 As the ray of light hits the PV cell, it essentially frees the electrons in the
semiconductor into the conduction band. The energy from a photon in sunlight transfers its
energy to an electron that is either in the valence or conduction band of the semiconductor. If the
electron stays in the same band after it is struck by the photon, then the excess energy received
from the photon will be released in the form of heat causing the temperature of the
58 Aldous, Scott. “How Solar Cells Work.” How Stuff Works. 02 Nov. 2002.
46 semiconductor to rise. A majority of the time, the electron is struck in the valence band. In this case the photon can either provide the electron with enough energy and momentum to reach the conductive band or the electron will fall back into the valence band.61
If the photon does not give the electron enough energy and momentum to fully reach the conductive band, then the electron will fall back into the valence band, in which case the initial photon is recreated. The recreated photon either gets reabsorbed or it emerges from the semiconductor in the form of heat. If the photon does give the electron enough energy to jump to the conduction band, then a hole will remain in the valence band in the spot that the electron just left. Since there are now free electrons in the conduction band and free holes in the valence band, our semiconductor can now produce electricity. However, indirect gap semiconductors require the electron to gain a significant amount of momentum in order to reach the conduction band. The momentum of an incoming photon is described by the equation below:
P = h/ λ Eq. 3.1.3
Where P is the momentum of the incoming photon, h is Plank’s constant, and λ is the wavelength of the photon. It turns out that this value is far less then the difference between the valence band maximum and the conduction minimum. A third particle, known as a Phonon, is required to be either emitted or absorbed by an electron in order to keep the conservation of momentum and send the electron into the conduction band.62
Once light strikes the semiconductor, the equilibrium of the electric field of the semiconductor is disrupted allowing the electron to escape from its position in the valence band sending it with enough momentum and energy with the help of the electric field into the
61 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995. 62 Ibid.
47 conduction band.63 The electron-hole pair that results now contains a significant amount of
stored energy. Due to the band gap of the semiconductor, there is usually an excess amount of
energy. This excess energy is released when the electrons and holes collide with the atoms of the
semiconductor. By colliding with these atoms, the temperature of the semiconductor will
increase and the electron will fall down to the bottom of the conductive band and the hole will
fall to the valence band edge. The energy of the resulting electron-hole pair will be equal to the
band gap energy, Eg, of the semiconductor. The electric field prevents the electron-hole pair
from recombining creating a voltage between the electron and hole, which is called the
photovoltage. The electrons and holes can also flow through an external circuit (or load) before
they recombine, which produces a current known as the photocurrent. The product of the
photovoltage and photocurrent corresponds to the net flow of energy from the PV system, which
came from the photons in sunlight.64
The electricity created from this process is known as Direct Current (DC) electricity. The
DC current is first sent through a charge controller, which regulates the charging of a battery if one is included in the PV system of the household and determines whether that battery needs to be charged or not. The problem with DC current is that a large majority of household devices run on Alternating Current (AC) because AC wiring is cheaper and safer than DC wiring. To fix the problem, the DC current is sent through a DC to AC converter, which basically changes the
DC current to AC. The resulting alternating current can be wired directly to a standard circuit breaker box making the installation of a PV system relatively easy.65
63 Aldous, Scott. “How Solar Cells Work.” How Stuff Works. 02 Nov. 2002.
48 The problem with solar power is that this process only occurs when light is absorbed. As stated before, sunlight provides energy to the Earth in the form of billions and billions of photons, and when they collide with electrons, electricity is produced.66 The light can either be absorbed, reflected, or can even pass right through the semiconductor.67 This can be demonstrated in figure 3.1.4 below.
Figure 3.1.4
In order to increase the number of photons absorbed, the percentage of photons that pass through and reflected must be reduced. The higher the absorption percentage is, the more efficient the
PV system will be.
When light is reflected off of the semiconductor, the light is now useless as the semiconductor fails to turn this light into electricity. The more light that is reflected off of the semiconductor, the efficiency of the solar panel will be lower. The equation below determines the fraction of which light is reflected of the surface of the semiconductor:
2 2 2 2 f = [ (n2 – n1) + k1 ] / [ (n2 + n1) + k2 ] Eq. 3.1.4
Where n1 is the real index of refraction and k1 is the extinction coefficient of the material when no light is shinning. The real index of refraction is n2 and k2 is the extinction coefficient when
66 Sayigh, A.A.M., ed. Solar Energy Engineering. New York: Academic Press, 1977. 67 “Turning Sunlight into Electricity.” Nation Center for Photovoltaics. 20 Oct. 2002.
49 light is shinning on the material. The smaller the value f is, the higher the efficiency rating of the
semiconductor is. A solution to this problem is to apply an antireflective coating to the
semiconductor. Figure 3.1.5 below shows the fraction coefficients for five different
semiconductors without an antireflective coating and with a single layer of silica antireflective
coating.68
Figure 3.1.5
As you can see in figure 3.1.5, the application of an antireflective coating will reduce the reflection coefficients for all the semiconductors.69 The antireflective coating causes an
equivalent drop for all of the different semiconductors indicating that the antireflective coating
affects the PV system the same regardless of the chosen semiconductor material. The actual
percentage drop for the reflection coefficient is determined by the antireflective coating that is
chosen and the amount of layers that are placed on the surface of the semiconductor.
Some of the photons from light pass straight through the semiconductor as if the
semiconductor were transparent. The photons in sunlight have a wide variety of different
68 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995. 69 Ibid.
50 wavelengths causing some to pass right through.70 The energy of a photon is determined by the
following equation:
Ep = hc/λ Eq. 3.1.5
Where h is Plank’s constant, c is the speed of light, and λ is the wavelength of the photon. The
photons that pass through the semiconductor have energy lower than the band gap energy of the
semiconductor.71 As a result, these photons do not contain enough energy to create an electron-
hole pair, so the photon just passes right through the semiconductor.72 To minimize the amount
of photons that pass through the semiconductor, many semiconductor layers are developed with
different band gaps in order to absorb the wide range of photon energy. Smaller photon energies
will require a semiconductor to have smaller band gap energy in order for the photon to be
absorbed. A semiconductor with lower band gap energy can absorb high-energy photons, but a
lot of energy will be lost due to the electron-hole pair emitting excess energy until its equal to the
band gap energy of the semiconductor material. As a result, some solar panels are implemented
with many layers of p/n junctions with different band gaps. The top layer of the solar panel will
have the highest band gap energy and the bottom layer will have the lowest band gap energy.73
The crystal structure or atomic arrangement of the semiconductor affects its ability and
efficiency in PV systems as well. The semiconductor can either be of crystalline,
polycrystalline, or of amorphous form. Solar cells can be made from any of these different
crystal structures. The use of different crystal structures can either give the semiconductor an
advantage or a disadvantage over the single crystalline structure. These advantages and
70 Aldous, Scott. “How Solar Cells Work.” How Stuff Works. 02 Nov. 2002.
51 disadvantages mainly come from the basic crystal structure, the direction in which the crystal is
facing, the actual semiconductor material used, and any new properties implemented through the
manufacturing process.74
Single crystalline solar cells are characterized by an ordered arrangement of component
atoms. Crystalline cells are efficient and are somewhat stable to ambient weather conditions, but
the cost for single crystalline cells are high. To generate and cut single crystalline cells uses a
tremendous amount of energy, greatly increasing the cost to manufacture the solar cell. As a
result, single crystalline cells are not as desirable.75
Polycrystalline solar cells have a bunch of single crystalline cells in a specific
arrangement pattern. Polycrystalline solar cells are relatively inexpensive to make and mass
produce, but they are not as efficient as single crystalline solar cells and they react poorly to
different ambient conditions. The cost to produce polycrystalline solar cells is due to a major
decrease in energy costs because the need for single crystal material is no longer needed.76 The decrease in the amount of energy consumed directly results in a decrease in the overall cost for the production of the solar cell. However, the prices are still too high to become a real competitor on the energy market. The lower efficiency and poor reaction to different conditions comes from the growth of the grain boundaries in the polycrystalline semiconductor material.
The grain boundaries separate the single crystals in the polycrystalline structure. These grain boundaries grow randomly resulting in a high number of defect sites in its crystal structure.
Electrical charges will get trapped in these defect sites, which can drastically reduce the
74 Sayigh, A.A.M., ed. Solar Energy Engineering. New York: Academic Press, 1977. 75 Mazer, Jeffrey A. SOLAR CELLS: An Introduction to Crystalline Photovoltaic Technology. Norwell, MA: Kluwer Academic, 1997. 76 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995.
52 efficiency of the material. Polycrystalline solar cells are much cheaper to produce than single crystalline cells, but they are not as efficient.77
Amorphous crystal structures have no particular pattern to them whatsoever. Amorphous semiconductors typically have wider energy gaps, higher absorption coefficients, and contain a substantial number of energy states in the forbidden gap. The wider energy gap allows the semiconductor to better match the solar spectrum resulting in higher absorption coefficients. The higher the absorption coefficient, the higher the efficiency rating of the semiconductor will be.
Due to the higher absorption coefficients, the solar cells can be manufactured with a much smaller thickness than crystalline and polycrystalline solar cells. The downside of amorphous semiconductors results from its large number of energy states in the forbidden gap. The forbidden gap is a section of electrons that are unable to reach the conduction band regardless of the energy of the photon. These electrons are useless because they do not help in the solar cell’s ability to produce electricity. As a result, the semiconductor cannot separate nearly as many electrons and holes. The result is a lower photovoltage and photocurrent causing the output of the solar cell to decrease. So the more electrons stuck in the forbidden gap, the lower the efficiency of the solar cell will be. Another downfall to amorphous semiconductors occurs after prolonged exposure to light, which also lowers the efficiency of the solar cell.78
Another limiting factor in the performance of solar cells is known as the dead layer. The effects from the dead layer do not take place for a long time and the actual time depends on the semiconductor material used. The dead layer is a portion of the semiconductor that has past its lifetime and can no longer produce an electrical current or voltage. The formation of the dead layer typically occurs at the illuminated surface of the semiconductor. The process used to
77 Mazer, Jeffrey A. SOLAR CELLS: An Introduction to Crystalline Photovoltaic Technology. Norwell, MA: Kluwer Academic, 1997. 78 Sayigh, A.A.M., ed. Solar Energy Engineering. New York: Academic Press, 1977.
53 design the solar cells decreases the lifetime at the illuminated surface, resulting in the creation of
the dead layer.79 Despite the long lasting, highly reliable, solar panels that are out there today, eventually the performance of the system will decrease slightly due to the increasing size of the dead layer. The problem comes from the electron hole pairs of the dead layer. A portion of the semiconductor is considered dead when the electron-hole pairs recombine before their energy can be utilized in the creation of electricity. When the electron hole pairs recombine, the absorbed energy from the photon is emitted as a form of heat rather than electricity rendering that portion of the semiconductor useless.80 The growth of the dead layer depends entirely on
how the type of semiconductor and how it is designed and will vary depending on the company.
Even though the dead layer grows as the solar panels ages, it takes decades to notice that the
solar system is performing any different.
The overall goal in designing solar cells is to construct a solar cell that is economically
feasible and can be competitive on the energy market. Single crystalline cells may have the best
performance, but the cost is too high to be competitive. The other crystal structures reduce the
cost making the implementation of polycrystalline and amorphous solar cells more cost effective,
but their efficiency is not as good as single crystalline cells. To this day, scientists are still
searching for new ways to implement solar cells to generate an economically feasible product
that can possibly overtake the dominance of today’s energy sources.
79 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995. 80 Neville, Richard C. Solar Energy Conversion. The Netherlands: Elsevier Science, 1995.
54 3.2 Wind Power
Wind Turbine Function and Production
The implementation of a large-scale wind turbine system can be very complex. In order
to reasonably propose such implementation, we must have a working knowledge of wind
turbines, their interaction with the wind, and the basic plan for installing them. In this section we will examine the components of two types of wind turbines, some of the physical principals involved in the function of wind turbines, and some of the economic considerations that affect the decision to develop a wind farm.
Basic Wind Turbine Function
There are two general types of wind turbines, synchronous and asynchronous. Both rely
on magnetic fields to transduce mechanical energy into electrical energy. However, the
differences in the turbines result in different applications and outputs for each. Although the
components of a wind turbine are designed with advanced aerodynamics and materials
engineering, the basic structure and function of the turbine are easy to understand.
There are several main components to a wind turbine: the rotor, the turbine generator, and
the tower. Fundamentally, the wind propels the rotor, which turns the generator that transduces
the energy, which is then sent down the tower to an electrical grid. The rotor is designed to
operate most efficiently at an optimal wind speed. Since gale force winds are very rare in most
places, it is not practical to optimize a turbine to high wind speeds, but rather close to the average
wind speed. The blades of the rotor are usually fabricated from glass-fiber reinforced plastics.
The head of the tower, where the rotor is mounted, usually has the ability to “yaw,” that is to
rotate so that the wind and the rotor are perpendicular. The turbine functions at maximum
55 efficiency when the wind and rotor are perpendicular because the rotors are aerodynamically designed to operate under that condition. That is to say that the aerodynamic parameters of the turbine rotors are such that perpendicular interaction with the wind generates a physical phenomena known as lift (see lift and drag section). The tower, which is generally made from cylindrical steel, serves as structural support for the rotor and also as a passageway for cables that carry electrical power from the generator to the grid. The height, weight and foundation of the tower are dependent upon the location of the turbine as well as the budget for building this turbine. The most complex and important part of the turbine is the generator, or the motor.
Synchronous generators involve a series of electromagnets centered on either a permanent magnet or another electromagnet. If the turbine is connected to an electrical grid, then the power from the grid will charge the outer electromagnets. The central magnet is connected to the rotor. When the rotor spins, the magnet spins in the middle of the electromagnetic field, generating a current, which is sent through cables down the tower. This turbine can also function without an electrical grid. If the electromagnets are not charged, the spinning magnet will still generate a magnetic field and consequently a current. This small current can generate power for limited power needs, i.e. a private homestead. This turbine is not often used to this end. If a permanent magnet is exposed to a strong magnetic field for a long time, it becomes demagnetized. Also, the cost of the electromagnets and the motor in general can be high.
Asynchronous turbine motors are a more common type of wind energy generator. They are based around aluminum or copper cylindrical cages rotating around an iron core. The rotor spins the cage around the core, and when an electrical grid charges the system, a strong magnetic field is created. The bars of the cage become polar and thus contribute to the magnetic field.
56 The harder (faster) the rotor is cranked, the more power will be transferred as an electromagnetic
force to a stator, or transducer. The transducer sends the electrical energy through cables into the
grid. This type of turbine must be attached to a grid. However, the costs of materials for this
turbine are less than those for synchronous turbines and also require less maintenance.
Consequently, almost all wind turbines to be used in large wind farms will contain an
asynchronous motor.81
Lift and Drag on the Rotors
The rotor of a wind turbine functions as a result of several aerodynamic principals. Of course,
the wind propels the rotor. However, there are two primary aerodynamic principals, which allow
the wind to move the rotor: lift and drag. Lift is the force that is generated by the wind that
drives the rotor upward. Drag describes an objects “resistance” to the wind. Lift and drag also
generate another aerodynamic concept: stall.
Rotor blades as well as airplane wings are designed so that the air on top of the blade or
wing moves faster than the air on the bottom. This is achieved by “pitching,” or titling, the rotor
blades so that the air moves smoothly and rapidly over the top part of the blade, while the
underside experiences slower wind movement. This creates a situation where the pressure above
the blade is less than the pressure below it. This design allows for the physical phenomenon lift.
Lift dictates that the high pressure region below the blade will push the rotor upward toward the
low pressure region. Lift always acts perpendicular to the wind movement. If the wind is
moving from right to left, then the lift force would be pulling the blade upward. This
phenomenon is what allows rotors to move with wind. This causes the rotor blades to move
81 “Asynchronous Induction Generators.” 06 Aug. 2000. Danish Wind Energy Association. 06 Nov. 2002.
57 “upward.” However, the rotor blades are anchored together around a central point, so the resulting motion is circular motion in a perpendicular plane to wind motion.
Another important consideration in rotor design is drag. The Danish Wind Industry
Association defines drag as the force generated in resistance to the wind. Because rotors must have fast tip speed, it is essential that they have very low drag. Drag is affected by several inputs. The most importand drag factor is the shape of the object. Drag increases in proportion with the frontal area of the object. Every shape generates different drag, and these drags are
defined by what is known as the drag coeffiecient (CD). The drag coefficient is the drag force per square meter frontal area of the object. The drag force can be calculated with the following equation:
2 FD = CD 0.5 ρA v Eq. 3.2.1
2 FD is the drag force measured in Newtons (N). CD is the drag coefficient measured in N/m . ρ indicates the density of the “fluid” through which the object is moving; for dry air at sea level at
15˚C ρ = 1.225 kg/m3. A is the frontal area of the object in m2. v is the relative wind speed (or speed of the fluid moving past the object). If the object is moving into a headwind, then that wind speed must be added to the speed of the object.
There is more than one kind of drag. Drag can be created by friction i.e. at low speeds dust particles can create drag. The force generated by the particles colliding with the rotor acts conversely to the motion of the blade, thus working against the power of the system. Drag can also be created by pressure differences around the object. If higher pressure is generated above the rotor blade in respect to the normal pressures, the rotor blade can be slowed. To determine which type of drag is involved, the Reynolds Number is used. The Reynolds Number is defined as
58 Re = v L / (µ /ρ) Eq. 3.2.2
Re is the Reynolds Number (dimensionless). v is the relative velocity of the “fluid,” in this case
air. L is the largest cross section of the frontal area. µ is the viscosity of the fluid, given in
Ns/m2. The viscosity of air is 1.8 x 10- 5 at 15° C and atmospheric pressure at sea level. ρ is the
density of the fluid in kg/m3. If the Reynolds Number is below 1, pressure drag can be ignored.
If the Reynolds Number is greater than 100, friction drag can be ignored.
Another strong consideration in rotor design is stall. Stall results when the air on the
upper surface of the blade stops sticking to the blade. As a result, the air begins to move in an
irregular vortex; this is known as turbulence. When turbulence occurs, the pressure above the
blade is no longer lower than below the blade and thus, the lift is reduced. Stall can happen as a
result of several factors. If the blades of the rotor are tilted to far in an attempt to increase lift,
the “angle of attack” of the wind increases, which can ultimately lead to turbulence. Also, if the
surface of the blade is not completely smooth or even, the imperfections can generate turbulence.
Dents and adhesive residue are common causes of rotor stall.82 With a basic understanding of
the design and principals behind wind turbine function, we can begin to assess the costs of
implementing a wind turbine system.
Installation and Maintenance Costs
The initial investment in installing a wind turbine is very high. The average cost of
building a new wind turbine varies with the kilowatt output of the turbine. A 150kW turbine
could cost between $150,000 and $170,000, whereas a 600kW turbine could cost between
$375,000 and $525,000. These costs are approximations based on typical geographical
82 “Aerodynamics of Wind Turbines: Stall.” 06 Aug. 2002. Danish Wind Industry Association. 20 Nov. 2002.
59 considerations and average wind speeds. The cost of building a turbine is heavily dependent upon where it is built. For example, a wind turbine built on a firm, flat ground is relatively inexpensive compared to a turbine set on a hill with a soft ground base. This is because a strong foundation system will be needed to support the system on the hill. However, increased installation cost become almost negligible in the long-term scope because areas with high installation costs (i.e. hills and offshore waters) tend to generate more energy.
Outside of installation costs, we must also consider the operation and maintenance costs of these systems. Maintenance costs are very low for a young turbine and the cost increases with turbine age. Routine yearly maintenance expenses usually fall into the range of 1.5-2% of the initial installation cost. However, these basic checkups may not be substantial enough to uphold the integrity of the system. There is usually an additional (or entirely separate) maintenance cost based on a certain amount per kWh. These maintenance costs take into consideration the wear that a system undergoes as a result of its output. If a wind turbine is near the end of its lifespan
(usually 20 years), it may be advantageous for the owner to undergo a major overhaul of the system (i.e. a new set of rotor blades, a gear box, or a generator). The cost of this type of maintenance is usually between 15 and 20% of the initial investment. These figures are averages based on the installation of a turbine with an engineered 20-year lifespan.
The efficiency of a wind turbine is dependent upon the energy that the turbine produces.
If we consider a 600kW turbine with a projected 20-year life span (installation ~ $585 000, operation and maintenance ~ $6 750/yr), the price per kWh varies with average wind speed at the hub of the turbine. At average wind speeds of greater than 10m/s, the cost per kWh could be as low as $0.02. At average wind speeds of less than 5m/s, the cost can be upwards of $0.12.
These figures are simple averages, as it is nearly impossible to accurately determine the
60 economics of wind turbine use. Different turbines in different geographical regions can have very different costs. This stems from the basic principal that it is more difficult to extract wind energy in some places than it is in other places, much in the same way that oils from different parts of the world have different prices.
Another very important economical consideration dealing with the price of wind turbines is the price per square meter of rotor area. The energy output of a turbine varies greatly with the rotor size. For example, if we compare a 600kW turbine with a 660kW turbine, assuming that the rotors are the same size, the energy output would not be very different. However, if we assume that the rotor of the second (660kW) turbine is 45% larger, the energy output will be
45% greater than the first (600kW) turbine (windpower.org). This nearly exact correlation between rotor size and energy output demonstrates the significance of the mechanical properties of the system as well as the geographical and weather considerations.
The size and weight of turbine systems can vary. The height of the tower is usually between 50 and 60 meters. Typically, the higher the tower is the more wind energy can be harvested. However, the cost goes up with the height if the tower, so the height is optimized based on a cost/efficiency comparison. These towers are constructed of sheets of steel that are rolled into conical sections and welded together. Towers of these heights generate a mass of anywhere from 40 metric tons to 80 metric tons. The average weight of turbine towers has gone down over 50% in the last 5 years. However, the massive weight of the tower can generate high transportation costs of parts from the manufacturer to the development site. Rotor size can also vary greatly. The size of the rotor is determined in much the same way as the size of the tower.
The larger the rotor diameter, the greater the energy output of the system will be. However, the cost grows with rotor length, as does the stress on the rotor. The average turbine has a rotor
61 diameter between 44m and 72m. Rotors can be as small as 25m and as large as 80m. Rotors are typically made out of glass-fiber reinforced plastics. This usually consists of glass reinforced polyester or epoxy. Carbon fiber and aramid are not often used because their expense outweighs their benefit in this application. The amount of energy that can be harvested by the rotors is dependent upon the area that they cover. However, this does not imply that most turbines have exceptionally large rotors. Cost is not the only factor in determining rotor size; most turbines are optimized for the area in which they are to be installed. In an area of marginal wind speeds, it is impractical to develop a turbine with exceptionally large rotors. The cost of moving equipment and site development (i.e. building new roads strong enough to support the weight of the turbine parts) can also influence to the builders’ decisions regarding size. Ultimately, the parameters of a wind turbine (i.e. rotor and tower size, maximum output) are determined as a result of many factors. There is no set algorithm for the development of turbines because every wind project has different geographical, environmental, and economical considerations.
Wind Energy Resources in the United States
In order for wind power to be seriously considered as a significant addition or replacement to our energy needs, we must establish that we have sufficient regions where there are suitable conditions for wind farm development. The primary consideration within this issue is, of course, wind activity in an area. Wind activity is defined in terms of wind power density.
Wind power is divided into seven classes as defined by table 3.2.1.
Areas designated class 3 or greater are suitable for most wind turbine applications, whereas class 2 areas are marginal. Class 1 areas are generally not suitable, although a few
62 locations (e.g., exposed hilltops not shown on the maps) with adequate wind resource for wind
turbine applications may exist in some class 1 areas.83
These wind power ratings are based upon areas that are free of any obstructions and are
geographically exposed to wind activity (i.e. plains, plateaus, and hilltops). Mountainous regions
can also be classified by this system, but the wind power readings come from exposed mountain
ridges and summits.
These wind classes are extremely important to the implementation of wind energy
because they allow us to objectively look at the United States in terms of what regions in the
country provide adequate wind resources that would allow for wind turbine implementation.
Based on data and wind power classes designated by the United States Department of Energy
subdivision RReDC (Renewable Resource Data Center), a clear picture of those regions in the
US that would support a wind turbine system is visible (geographical and economic
considerations notwithstanding). A large portion of the United States has wind activity
conducive to wind farming. Class 7 wind power ratings can be seen in plateau regions ranging
from Montana to Arizona. The Massachusetts coast also offers class 7 ratings. These are not the
only areas that have suitable wind conditions in the US. As stated earlier, regions of class 3 or
higher will also usually support wind turbines. These areas include an expansive region ranging
from western Michigan to eastern Montana and down through Oklahoma and northern Texas as
well as most of New England and the Appalachian stretch. Most of Texas virtually the entire
Great Lakes region and west coast have power classes between 2 and 4, which could be suitable
for wind farming. Conversely, the southeast US from Virginia through W. Virginia and
Tennessee down through eastern Texas and Florida has a power class of 1.
83 “Wind Energy Resource Atlas of the United States.” National Renewable Energy Laboratories. 03 Dec. 2002.
63 An important thing to understand when dealing with these wind classes is that they are
not determined simply by wind speed. The wind power density must be related to the wind
speed to determine a class. At sea level, the wind speed and wind power can be directly
correlated as table 3.2.1 shows. However, the decrease in air density with higher altitudes
requires lesser wind speeds to achieve the same class rating. These wind power density ratings
are not an exact tool. They provide a usable tool in determining wind activity in certain areas, but they do not represent an exact and rigid description of wind activity. The topography of the land as well as the availability of reliable measurements in the area can create a degree of certainty in relation to the class rating. RReDC uses a certainty scale based on variations in topography and measurement availability. The scale ranges from 1-4, with 4 being the most certain about the data collected. These certainty ratings must me used in correlation with the class ratings to fully understand the spectrum of a region’s wind power potential. For example, the certainty in the mountainous regions (Rocky and Appalachian) is 1, so the class ratings assigned to those areas may be inconsistent. The southeast, as well as much of California and
Massachusetts have certainty ratings of 3 or 4, thus the wind power classes assigned to those areas are fairly accurate.
Also to be considered is the terrain of a given area. An increase in the roughness of terrain signifies a decrease in the percentage of land area that is exposed to the wind. The percent of land area exposed to the wind is another key factor in determining wind farm feasibility. The mountainous regions of the US have anywhere from 0 to 20 percent of land exposed to wind, whereas the region ranging from North Dakota down through northern Texas as well as the eastern seaboard (specifically Cape Cod) has as much as 80 to 100 percent of its land area exposed to the wind. The implications of such exposure are tremendous. For example,
64 much of the Rocky Mountain stretch has a power class of 4 or higher. However, less than 20% of the land in that area is exposed to that wind. This along with the mountainous terrain would make it a very unlikely spot for the development of a wind farm, despite the high-class rating.
An area of lower class rating with greater exposure to wind would be much more suitable. The
American Midwest is a prime example of this. Most of that region has a power class of 3 or 4, yet upwards of 100% of the land is exposed to the wind activity. This region would be far more suitable for wind farming than the mountains despite inferior wind power ratings. For the purposes of creating a wind farm model, we will only consider areas with a class rating of 6 or higher, a certainty rating of at least 3, and land area exposure of at least 60%. By focusing on these areas, we are dealing with regions with accurate wind power ratings and suitable geographic considerations.
65 Wind Power 10 m (33 ft)
* Class Wind Power Density (W/m2) Speed(b) m/s (mph)
0 0 1
100 4.4 (9.8)
2
150 5.1 (11.5)
3
200 5.6 (12.5)
4
250 6.0 (13.4)
5
300 6.4 (14.3)
6
400 7.0 (15.7)
7 1000 9.4 (21.1)
Table 3.2.1 – US Wind Power Class Ratings.
Source: Renewable Resource Data Center (http://rredc.nrel.gov)
66
4.0 MODELS
4.1 Solar Power
A total area of the solar panels in m2 c constant depending on weather conditions and the angle of the sun d # days in particular month L portion of daylight hours in a day P Amount of electricity produced s data determined from NREL’s solar radiation maps in kWh/m2/day
25MW Solar Power Plant Model
Southern California has struggled with an energy crisis for the past couple of years. The major factor causing California’s power shortage is mostly due to the insufficient amount of electricity produced by its utilities. A vast majority of California’s utilities struggle to prevent themselves from shutting down. When some utilities do shut down, the state of California cannot generate enough electricity to keep up with the high demand. As a result, Southern
California has found itself becoming a victim of numerous brownouts and blackouts over the past couple of years. Many utilities would buy energy to sell to customers, but the cost for the utilities to buy the electricity was higher than what they were allowed to sell it at due to
California legislation freezing the electricity rates. Also, the cost to upkeep the power plants to meet California’s power plant emission requirements were quite high. These two factors led many utilities into financial problems and to eventually shutting down. As this occurred, total power generation decreased and could not meet the demand leaving us with a major energy
67 crisis.84 A solar power plant can avoid most of the problems that California’s power plants encounter daily and be an economically feasible choice.
Southern California is one of the best locations in the United States for solar power plants. The reason is greatly due to the enormous amount of sun energy that strikes Southern
California on a daily basis. However, there are many other factors that make solar power a beneficial choice. Solar power has very low maintenance costs and can last up to twenty years before seeing any large maintenance fees. The sun is a free and extremely clean source of energy, which avoids a large majority of the problems that most of California’s utilities struggle with.85 To get an idea of how effective solar power can be in Southern California, figure 4.1.1 below shows the averaged worst-case insulation hours in the United States. The insulation hours are a form of measurement that determines how well a solar power system will function in a certain area. The higher the number, the more productive a solar panel will be.
Figure 4.1.1
84 “Subsequent Events: California’s Energy Crisis.” 08 Aug. 2002. Energy Information Administration. 16 Jan. 2003.
68 As you can see from figure 4.1.1, Southern California is a prime location for a solar power plant
because of the high insulation hours rating. Parts of New England range from 2.0 to 3.0
insulation hours, where Southern California varies from 4.5 to 5.5. Southern California receives
almost twice the energy from the sun than New England. For example, if a solar power plant
was built in California, the owners can see a return on investment in less than twenty years.86
The initial investment for a 25MW solar power plant is quite large, but the low upkeep costs and reliability far outweigh the initial investment. There are many parts that go into making a solar power plant. The following parts are needed: solar panels, mounting kits, DC to
AC inverters, land, wiring, and meters.87 The total initial investment for all of the necessary
parts comes out to be roughly $160 million.
The solar panels are by far the most expensive portion of the initial investment. After
sifting through many different solar power suppliers, the BPSX-140S model made by the BP
Solar gives us the most watts per dollar. It’s a 150W panel for $555 with a twenty-year
warranty. The price for this system is about average compared to most other panels, but its
power output is about 20 watts higher than most other panels making the BPSX-140S an
economical choice.88 To achieve a 25MW system, our solar power plant will need at least
166,667 of these BPSX-140S panels. The panels do not always work at peak efficiency, so we
added another 333 panels to compensate for some of this and to have a nice round number of
solar panels. The total number of panels now comes up to 167,000 panels. Since each panels
costs $555, the total cost for the solar panels for our 25MW system comes out to be $92.7
million. The cost for the solar panels covers approximately 60% of the initial investment.
86 “How Much Will a Solar Module Produce in my Location?” Online Solar, Inc. 21 Jan. 2003.
69 However, the twenty-year warranty on these devices ensures that the solar panels are well worth the cost. The twenty-year warranty ensures that our solar panels will be fully function for at least twenty years. As a result, the yearly maintenance costs for the 25MW system will be extremely low.
The solar panels now need some mounting kits to placed upon. The number of panels that can fit on the mounting kits depends entirely on the size of the panels and the surface area of the mounting kit. To achieve the best efficiency from our solar panels and generate as much electricity as possible, tracking mounts were selected. Tracking mounts track the sun keeping the panels perpendicular to the sun throughout the day. If our solar panels were mounted in a fixed position, then the amount of solar radiation striking our panels will be lower due to the sunlight striking the panels at an angle throughout most of the day, decreasing the overall production of the 25MW system. Solar panels generate the most electricity from direct sunlight, making the tracking mounts the most efficient choice. The UTRF120 is the most expensive tracking mount per unit at $1572, but in the end the UTRF120 is the most cost effective. The model below the UTRF120, the UTRF90, can hold six of the BPSX-140S solar panels rather than eight at a cost of $1364.89 As a result, 27,784 UTRF90 mounts would be required to mount all of the 167,000 solar panels. The total cost for the mounts if the UTRF90 mount was selected would be $37.9 million. Since only 20,838 UTRF120 mounts would be required, the cost reduces to $32.8 million, which is $5 million cheaper and utilizes a much smaller land area, which will also reduce the amount of land needed.
Solar power systems create Direct Current (DC) rather than the typical AC current produced from the modern power plant. A large majority of houses utilize AC current rather
89 “Track Racks.” Online Solar, Inc. 21 Jan. 2003.
70 than DC because AC wiring is cheaper and safer than DC wiring.90 For the electricity that is generated from our solar panels to be compatible, a DC to AC inverter is required to switch the generated DC current to AC current. The PP-SW5545/D DC-AC inverter can handle up to
11,000W at $7,986 per unit.91 With a 25MW solar power plant, 2,300 inverters will be needed to
handle the max output from the solar panels. The total cost for the DC to AC converters is $18.4
million.
The whole solar power system will require a lot of wiring and land to construct the
25MW system. A variety of meters will be needed to constantly check the output levels of the
solar panels and other various types of meters will be needed to ensure that the 25MW system is
functioning properly. Two million dollars will be allocated to the purchase of these meters. The
wiring for the system is quite simple and can be purchased in bulk for under $2 million.
Approximately 3 million square feet of land will be needed to spaciously fit the solar power
system. The land can either be leased or purchased. The actual cost for the land can vary
depending on the location and value of the land, but for the sake of simplicity, lets assume that
the cost for the land will not exceed $5 million. Solar power systems are simple systems and do
not need a large number of different components in order to operate.92 However, there may have been some small but essential components that have been unintentionally left out of this model, so lets allocate $5 million to cover any unknown components that may be needed.
The land, meters, wiring, DC to AC inverters, solar panels, and mounting kits all compose the 25MW solar power system. The initial investment required getting the system up
90 “Solar Electric System Basics.” New York Solar Energy Industries Association. 31 Oct. 2002.
71 and running is the sum of all of the components listed above. The initial investment for a 25MW
solar power system is $157.9 million.
The initial investment will decrease due to the large number of purchased products.
When purchasing a very large quantity of an item, the cost per unit typically drops. After talking
to the people from Online Solar Inc., they were not positive of an exact discount due to unknown
costs involving the production of these panels. However, they did estimate that a 10 percent
discount was a reasonable value. The initial investment now drops from $157.9 million to
$142.1 million.
The initial investment is still quite high, but due to many different incentive programs out
there, especially in California, the initial investment drops down drastically. California does
have some great incentives out there, but most are strictly for residential and commercial
customers. The Renewable Energy Production Incentive (REPI) is one of the incentives out
there for utilities to take advantage of. The Renewable Energy Production Incentive states that
Geothermal, Wind, Biomass, and Solar utilities will receive 1.5 cents/kWh generated for the first
ten years of operation.93 The total rebate accumulated will account up to $16.6 million after 10
years. This amount depends on the total electricity produced in the ten-year span, which will be
derived later. Knowing that the $16.6 million will come throughout the first ten years of
operation, we can subtract the $16.6 million from the total investment. The total investment now
comes out to be $125.5 million rather than the $157.9 million we started off with, a 20%
reduction in cost.
In order to determine the number of years it will take to see a return on investment, we
must first determine how much electricity our solar panels can generate in a year. Utilizing U.S.
93 “DSIRE: Database of State Incentives for Renewable Energy.” Online Solar, Inc. 12 Feb. 2003.
72 solar radiation maps generated by The National Renewable Energy Laboratory (NREL), we can determine a range of how much energy our panels can actually produce. The U.S. solar radiation maps give the average, minimum, and maximum values in kWh/m2/day that strike our panels for a given location.94 By utilizing the minimum and maximum solar radiation values, we will be able to determine a range of electrical production to see how far our return on investment can deviate from the average. The options include values for each of the twelve months in a year and the solar radiation will vary depending on the mounting kit used in the solar power system. For our data, we will be utilizing the average, minimum, and maximum solar radiation data per month using two-axis tracking mounts that are generated from NREL. The solar radiation maps for our model for the month of March can be seen below.
Figure 4.1.2
94 “U.S. Solar Radiation Resource Maps.” National Renewable Energy Laboratories. 04 Feb. 2003.
73
Figure 4.1.3
74 Figure 4.1.4
The data shown on these maps are generated from the solar radiation data in the month of March
from 1961 to 1990. From the average daily solar radiation map, the area of Southern California
is in the brown. As a result, the solar radiation striking Southern California varies between seven
and eight kWh/m2/day on an average. The lowest recorded solar radiation per day for the month
of March between the years of 1961 and 1990 is approximately 5.5, the highest is 9.0, and the
average solar radiation per day is 7.5.95 Nowadays, the actual solar radiation will be slightly higher than the average due to global warming effects, making the amount of electricity produced by our solar panels in a year slightly higher. Table 4.1.1 shows the corresponding averaged, minimum, and maximum data for each month in the year.
Minimum Average Maximum Solar Solar Solar Month Radiation Radiation Radiation 2 2 (kWh/m /day) (kWh/m /day) 2 (kWh/m /day) January 4.0 4.0 7.0 February 4.5 6.0 8.5 March 5.5 7.5 9.5 April 7.0 9.0 12.0 May 8.5 10.0 13.0 June 9.0 11.0 14.0 July 9.5 12.0 14.0 August 9.0 10.0 13.0 September 7.0 9.0 11.0 October 6.0 7.5 9.0 November 5.0 6.0 7.0 December 4.0 5.0 7.0 This data was generated from the maps provided by the National Renewable Energy Laboratories.96 Table 4.1.1
95 “U.S. Solar Radiation Resource Maps.” National Renewable Energy Laboratories. 04 Feb. 2003.
75 To get a specific value rather than a range of values, the minimum value in that range is assigned to the month if our area is located near the edge of a section with a lower solar radiation, a maximum value in the range is assigned if our area is located near the edge of a section with a higher solar radiation, and the average of the maximum and minimum is assigned if our area is located in the middle of the section. Utilizing the data generated from these solar radiation maps, we can determine the average, minimum, and maximum amounts of electricity that our panels can produce per month and then determine the average, minimum, and maximum annual production of electricity.
To determine how much electricity our panels produce in a month, we must use the following formula:
P = c * L * A * s * d / 1000 Eq. 4.1.1
Where P is the amount of electricity produced in Megawatts, c is a constant depending on weather conditions and the angle of the sun, L is the portion of daylight hours in a day, A is total area of the solar panels in m2, d is the number of days in the month, and s is the data determined from NREL’s solar radiation maps in kWh/m2/day. In poor weather, the solar panels cannot produce as much electricity due to the sun being hidden behind the cloudy and/or hazy skies, so this needs to be factored into the amount of electricity produced. The sun also supplies the Earth more energy when it is perpendicular to the ground, but this is not the case for most areas in the
United States. As a result, if the angle of the sun is large, then the amount of electricity that can be produced by our solar panels decreases. Both the poor weather conditions and angle of the sun will be factored into the constant, c. To determine an appropriate value for c, we used the formula above to determine the predicted amount of electricity produced in a year from a location in Maine and compared it to the actual recorded amount of electricity that location
76 produced in that year.97 The actual amount of electricity produced was on an average, approximately 43% smaller than what our formula shows. The value for c then becomes 0.43.
However, the sun is at more of an angle and the weather is worse with a lot more cloudy days in
New England than in Southern California. As a result, the actual value of c for our solar panels will be higher then that of 0.43, but we can use it to determine a more conservative scenario for our electricity production per year. By assuming that there are only ten hours of daylight time in a day year round, we can achieve a better worst-case scenario in our annual electricity production. By making the last two assumptions, we can conclude that the electrical production per year for our 25MW system will be slightly higher than what we will predict. The area per solar panel is 1.254m2 per panel, so the total area (A) for the system is 209,041.8m2.
Using equation 4.1.1 and the values derived above, we can establish how much electricity our 25MW system can produce in the month of January. The area remains the same for all months as well as the constant, c. Using these numbers, we can determine the average amount of electricity generated in the month of January:
P = (0.43)(10/ 24)(209041.8)(4)(31)(1/1000)
P = 4179.79MW
In the month of January, our solar panels will produce an average of 4,644.8 MW of electricity.
Using the same formula, the minimum amount of electricity our solar panels can produce is
4,644.8 and the maximum amount is 8,127.4 in the month of January. The average, minimum, and maximum electrical production for the twelve months in a year can be seen in table 4.1.2 below:
97 Lord, William and Deborah. “Maine Solar House.” 05 Dec. 2002.
77 Month Minimum Average Maximum Electricity Generated Electricity Generated Electricity Generated Per Month Per Month Per Month (MW) (MW) (MW) January 4,644.80 4,644.80 8,127.40 February 4,719.10 6,292.16 8,913.90 March 6,385.80 8,707.90 11,030.00 April 7,865.20 10,112.40 13,483.20 May 9,868.90 11,610.53 15,093.70 June 10,112.40 12,359.60 15,730.40 July 11,030.00 13,932.64 16,254.70 August 10,449.50 11,610.53 15,093.70 September 7,865.20 10,112.40 12,359.60 October 6,966.30 8,707.90 10,449.50 November 5,618.00 3,741.60 7,865.20 December 4,644.20 5,805.26 8,127.40 Annual 90,169.40 110,172.7 142,528.70 Production Table 4.1.2
From these numbers, we know that the total electricity produced by our 25 MW system for all twelve months will be equivalent to our annual production. The amount of electricity produced in a year should be no less than 90,169.40MW and no higher than 142,528.70MW. The minimum and maximum electricity generation per year are stretched out to worst-case and best- case scenarios for a given year. It is impractical for one year to contain all of the lowest or highest values of solar radiation data received from various months in a thirty-year span. Rather, a combination of high solar radiation months will be mixed in with low solar radiation months throughout any given year. As a result, the actual production per year for our 25MW system will typically hover around the average electrical production in a year, which is 110,172.7MW. Now that we know approximately how much electricity our solar panels can produce in a year, we need to find out the electricity rates per year, which will allow us to determine our gross per year.
The current rate for electricity in California is approximately $0.1/kWh. For every kW produced and sold, the company will receive a certain amount of money for that kW depending
78 on the Electricity rates. Figure 4.1.5 shows the gradual increase in electricity rates for today’s
primary electricity sources from 1980 – 2000 and the projected electricity rates up until the year
2012 for the state of California.98
Electricity Rates for the Modern Power Plant 20 18 16 14 12 10 8 6
Cost (cents/kWh) 4 2 0
80 82 84 86 88 90 92 94 96 98 00 02 04 06 08 10 12 20 20 20 20 20 20 20 year
Figure 4.1.5 The increase in electricity rates for today’s primary sources is growing due to the depleting supply of fossil fuels and inflation. The projected rates in the figure above are the approximated rates that modern power plants will be able to sell their electricity while still earning some profit.
The cost for solar power systems is gradually decreasing allowing the owners of that solar power system to sell electricity at lower costs giving solar power systems a huge advantage in the electric market.99 Knowing that the electricity rates will gradually increase over the years, solar
power systems can sell their electricity at a few cents cheaper than the going rate. Consumers
will choose to have their electricity supplied by solar power because they are the cheaper
electricity source. Since the electricity rates are gradually increasing, the owner of the solar
98 “Utility-Wide Weighted Average Retail Electricity Prices.” 25 Mar. 2002. California Energy Commission. 10 Feb. 2003.
79 power system will see an increase in their profits year after year. Using the data from the figure
above, we can determine how much gross our 25MW system can make per year.
The amount of electricity produced per year from our solar panels can vary anywhere
between 90,169.40MW and 142,528.70MW. The gross for a given year is the amount of kWh
sold times the electricity rates. In 1990, the electricity rates were 7.98 cents/kWh.100 In 1990,
our 25MW system would have grossed no less than $7.2 million and no greater than $11.4
million. Knowing that the actual electrical production will hover nearer to the average and that
our solar power plant produces an average of 110,172.7 MW/year, our expected gross will be
about $8.8 million per year. The $8.8 million grossed in 1990 accounts for 7% of the total
investment made. As each year passes and the electricity rates grow, a larger percentage of the
total investment will be made back each year. A graphical representation of our return on
investment is shown in Figure 4.1.6 below given the data for electrical rates between 1990 and
2010.
100 “Utility-Wide Weighted Average Retail Electricity Prices.” 25 Mar. 2002. California Energy Commission. 10 Feb. 2003.
80 Return on Investment
160 140
120 Minimum 100 Average 80 Maximum 60 Investment 40 Dollars (Millions) 20 0 0 5 10 15 Time (years)
Figure 4.1.6
The point at which the profit and the initial investment curves meet is known as the return on investment point. As you can see from figure 4.1.6, a return on investment can be seen no earlier than 10 years and no later than 16 years. Since the actual energy produced in a year will be near the average, the solar power plant will see a return on investment closer to 13 years rather than
10 or 16 years. Once enough gross is made to pay off the initial investment, the gross curve exceeds the investment curve indicating that a profit is now being made. The investors will begin to see that the money they spent to construct the 25MW solar power system was beneficial and well worth the investment.
The actual slope of the gross will vary depending on the actual amount of electricity produced per year and the electricity rates for that year. From the figure above, the investment is horizontal, indicating that no other payments needed to be made. However, the yearly cost of maintenance will give the investment curve a slight slope and there is always a risk of an unforeseen cost in the future, but should not be to any substantial amount. The maintenance
81 costs for the solar power system are very low due to the long warranties for a large majority of
the components that make up the 25MW solar power system.101 Any maintenance costs that do
arise will be minor up to the point when the warranties on the solar panels expire because the
solar panels consist of 60% of the total investment. A warranty does not dictate that the device
will die after the warranty expires. However, products have a tendency to last for a much longer
period of time than their warranties. Otherwise, it would not be profitable for a company to
replace a majority of the products they sell due to their inability to outlive their warranties.
Once the initial investment is paid off, the highly reliable 25MW system will begin to
show a profit. As soon as the warranty on the solar panels expire and begin to need replacing,
the maintenance costs will increase slightly, but to no sever degree. The reason is that the new
solar panels will also have twenty-year warranties and the cost to replace these new solar panels
will not arise for at least another twenty years. The investors and owners of the system will earn
a generous profit year after year for the remainder of the solar power systems lifetime. The
initial investment for the solar power system is quite large, but as soon as the investment is paid
off, the system will prove itself to be a beneficial and economical choice all around.
One major contributing problem to California’s energy crisis is the overwhelming
demand for electricity during the summer months.102 Ever since the air conditioner was invented, the demand for electricity in the summer has increased tremendously. Electricity consumption has increased so much that California has been having problems supplying enough electricity to meet these demands over the past couple of years.103 California has taken action to
101 Online Solar, Inc. Home Page. 22 Jan. 2003.
102 “2002 Monthly Electricity Forecast.” California Energy Commission. 16 Jan. 2003.
82 increase the efficiencies of devices that use a lot of electricity (i.e. air conditioners) in order to
eliminate the problem. However, California still finds itself struggling to supply enough
electricity to meet the high demand of the summer.104 The average monthly peak electricity
demand from the years 1993 to 2000 is shown in figure 4.1.7 below.
Average Monthly Peak Electricity Demand (1993 - 2000) 40000 38000 36000 34000 32000 30000
Demand (MW) Demand 28000 26000 24000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Demand Month Supply
Figure 4.1.7
The demand curve from the figure above is generated from the data obtained from California’s
Energy Commission.105 As the demand for electricity increases/decreases throughout the year,
the amount of generated electricity remains the same, which is indicated by the horizontal slope
in the figure above. The electricity supply shown above is an example and not the average
supply from 1993-2000. Problems occur when the demand rises above the supply. When the
demand rises above the supply, there is not enough electricity to take care of the entire demand.
What happens is that the available electricity is sent out evenly to all of the locations demanding
electricity, but there is not enough electricity to power the devices to their fullest. For example,
104 “Subsequent Events: California’s Energy Crisis.” 08 Aug. 2002. Energy Information Administration. 16 Jan. 2003.
83 streetlights and lamps will dim creating brownouts and in some scenarios blackouts occur. Solar power systems are highly effective during summer times when the demand for electricity is very high.
Using the data generated from our 25MW model, we will see how solar power systems benefit from high demand situations in the summer. To graphically demonstrate this benefit, the figure 4.1.8 was generated showing the trend of electrical production for each month in a year.
Electrical Production Trend
18000 16000 14000 12000 10000 8000
Electrical 6000
Production (MW) Production 4000 2000 0 Minimum Jan Feb Mar Apr May Jun July Aug Sep Oct Nov Dec Average Maximum Month
Figure 4.1.8
The actual amount of electricity produced per month will depend entirely on the weather conditions and climate of that month, but will not exceed the maximum or minimum trends. As you can see in figure 4.1.8, the solar panels consistently produce approximately three times the electricity during the summer months than in the winter months. Our 25MW solar power system has a huge advantage due to this fact. Looking at the two figures, you can see that the trends are similar. As the demand for electricity increases during the summer months, the electrical production from the 25MW solar power system automatically increases due to the high solar radiation of the sun at this time of the year. A majority of the utilities in California need to purchase more materials in order to supply the highly demanded electricity during the summer,
84 whereas the sun provides our 25MW system with three times the energy than in the winter in
order to produce the extra electricity demanded in the summer.106
In years to come, the cost for today’s primary electrical production methods will gradually rise.107 As we head into the future, we will need to discover newer methods to
generate our electricity. At this point in time, fossil fuels are one of the primary and most
economical methods used to create our electricity. However, the world’s fossil fuel supply is
depleting raising the electricity rates.108 The supply and demand for fossil fuels determines its
market price. A typical supply and demand curve is shown below in Figure 4.1.9.
Demand Supply and Demand Supply
25
20
15
Price 10
5
0 6 8 10 12 14 16 18 20 Quantity
Figure 4.1.9: The values in this figure are for example only and do not demonstrate actual fuel prices.
Analysis of figure 4.1.9 is quite simple. The point at which the curves intersect determines the
market price for the fuel. From the graph above, the price would be approximately 13. As time
goes on, the world’s supply of fuels will decrease while the demand for electricity will increase.
When the supply of a certain product decreases, the supply curve is shifted to the left, and when
the demand for that product increases, the demand curve is shifted to the right. This supply and
106 “Subsequent Events: California’s Energy Crisis.” 08 Aug. 2002. Energy Information Administration. 16 Jan. 2003.
85 demand relationship determines the price that power plants purchase their fuels for. The
intersection point will now occur at a higher point on the y-axis resulting in a higher priced
product. As the price for fossil fuels gradually increase, utilities will be forced to raise the
electrical rates in order to retain a profit. Without the fuel to power the turbines in power plants,
the power plants cannot generate electricity, which will eventually force the plant out of
business. In order for the plant to stay in business, they must buy the higher priced fossil fuels
and raise the electricity rates sold to their consumers. The drastically increasing electrical rates
in the late 90’s were becoming a major problem in the state of California, so the state froze the
electricity rates at 6.5 cents/kWh. Many California utility companies struggled financially
because they were buying the materials to generate the electricity at higher prices than the state
was allowing them to sell. This forced many utilities into major debts, also contributing to the
energy crisis in California.109 Solar power systems completely avoid this scenario entirely. The
electricity rates for solar power systems have no dependence on the cost for its energy source
since the sun shines freely on the earth everyday. As a result, solar power systems will not
struggle financially due to rising prices in limited resources, but thrive in the energy market of
unlimited resources.
As of right now, the average solar power electricity rates are too high to be competitive
with modern power plants. However, over time the cost to produce the solar panels will directly
result in an exponential decrease in the electricity rates that solar power systems can sell at is
shown below in Figure 4.1.10.
109 “Subsequent Events: California’s Energy Crisis.” 08 Aug. 2002. Energy Information Administration. 16 Jan. 2003.
86 Solar Power Prices
35
30
25
20
15
10 Cost (cents/kWh) 5
0 12345678910 Years
Figure 4.1.10
The point at which the solar power electrical rates intersect with the trend of modern utility electric rates is the day solar power will be competitive in the electrical market. The actual amount of time it will take for solar power to be competitive is unknown due to the difficulty in predicting its future. However, the electricity rates for modern power plants are rising and the electricity rates for solar power systems are decreasing indicating that the day solar power is competitive in the electrical market is growing nearer and nearer. Modern power plants are slowly becoming obsolete as their electrical rates are slowly rising into an uneconomical level.
The electrical rates for solar power plants are slowly decreasing to an economical level, bringing solar power closer and closer to being the more economical choice pushing modern power plants out of business.
Case Study
Bill and Debbie Lord of Southern Maine own one excellent example of an energy efficient solar power system. The 4.2kW PV system is implemented on the roof covering 384
87 sq. ft. of space and generates approximately 4,000 to 4,500 kWh per year. The system is designed with sixteen 4’ X 6’ panels that provide the house with 4.2kw of power at 48 volts.
Since solar power creates DC voltage, the Lords needed a DC to AC inverter in the house. They own two Trace Sun Tie XR Inverters, which have more than enough capacity to handle the electrical load being generated by the solar system. The 4.2kW system produces more then enough energy to fulfill the household with all its needs. The family constantly finds itself in a surplus of energy by the end of the year. Figure 4.1.11 below gives you a good bird’s eye view of the Lords’ home.
Figure 4.1.11
The solar panels are actually attached right to the roof even though it appears to be tilted off the roof a bit.110 Notice how no snow accumulated on the solar panels at all, and there is visible snow accumulations on the other portions of the roof. When sunlight strikes the solar panels, the solar panels heat up slightly, melting any snow that has accumulated. This proves that solar panels will work well during the snowy winters of the North. The Lord house demonstrates a major step in the evolution of solar power.
110 Lord, William and Deborah. “Maine Solar House.” 10 Dec. 2002.
88 However, due to the positioning of the sun during the winter months, the solar system cannot provide the house with enough energy to suite their needs. To achieve a successful design, the system is connected to a utility grid (Central Maine Power) so the house always has enough electricity to fit the family’s needs. By connecting to a utility grid, it also negates the need for a battery to store energy to be used during periods of time where the solar power system cannot provide enough for the entire house. During the winter months, the solar power system does not generate a sufficient amount of electricity to support the needs of the family. As a result, the house draws more power from Central Maine Power than they send out. In the summer months, the system produces more electricity than the household uses so the house sends out up with a surplus of electricity. Since Maine is a “annualized net metering” state, meaning that any excess energy produced can be used to cancel out any energy deficits. By the end of the year, the Lord household typically produces 300 to 500 kWh more than they use, so the Lords are only stuck with the $8/month hook-up charge to the Central Maine Power grid. If the Lords find themselves borrowing more electricity than supplying then they must pay 12 cents/kWh.111
The years of 1998 and 1999 were both successful years for the Lord household. They had a surplus of electricity of 591kWh in 1998 and 352kWh in 1999. Figure 4.1.12 demonstrates net energy per month in the year of 1998.
111 Lord, William and Deborah. “Maine Solar House.” 10 Dec. 2002.
89 Net Electricity per Month in 1998
300 200 100 0 -100 123456789101112 -200
Electricity (kWh) -300 -400 Month
Figure 4.1.12
Figure 4.1.12 clearly indicates that the solar panels generate a lot more electricity than consumed during the months of March to October. November through February produce by far the least amount of energy out of any of the other months. This is largely due to the angle of the sun during the winter months. However, the solar panels generate enough electricity from the spring to fall seasons to cover the lack of electricity production during the winter months. In 1999, the
Lords used a larger quantity of electricity throughout the year only achieving a surplus of
352kWh. The Lords admit that the decrease in surplus is due to staying at home year round during that year, which increased their overall power usage.112
Despite the surplus of energy year after year, only half of the solar power system is dedicating to generating this energy. The other half is dedicated to generating hot water and heat for the entire home. Heat is a very important aspect of living in Maine since the temperatures stay below freezing throughout most of the winter. The water circulates through the roof,
112 Lord, William and Deborah. “Maine Solar House.” 10 Dec. 2002.
90 increasing the temperature of the water as it flows and is stored in two 500-gallon tanks in their
basement. This water is then used to heat and provide the entire house with hot water.113
The Lords own a 4.2kwH PV system, which cost them around $30,000. $30,000 is about the price of a nice car. A large PV system is required to heat and power the entire house due to its size. The Lord home has 3 bedrooms, 2 ½ bathrooms, a living room, kitchen, and an entertainment room. Smaller houses will not require as large of a PV system to heat and power and since most homes are smaller than the Lord home, the investment will be less expensive.
The Lords purchased a PV system that would leave them with a surplus of energy at the end of each year, so there is only the monthly hook-up charge that they need to concern themselves with. After their initial investment of approximately $30,000, they only need to pay $8 per month to be connected to Central Maine Power.114
It has been doubtful that solar power can be successful in Northern parts of the country.
This is due to the smaller amounts of sun energy reaching the Earth and shorter daylight.
However, the data that the Lords have provided demonstrate that solar power systems can be
successful in Northern parts of the country. A much larger system would be needed in Maine to
generate the same amount of energy that a smaller system in Southern California would generate.
Despite the requirement for a larger system, $30,000 is not an overwhelming amount of money
for middle to upper class people, but it is still too high for people to find it a beneficial
investment. As the prices decrease and as the efficiencies of solar power systems increase, the
demand for solar power systems will rise as solar power becomes a more beneficial choice.
Even though the prices might still be too high for some people, the Lord household demonstrates
113 Ibid. 114 Lord, William and Deborah. “Maine Solar House.” 10 Dec. 2002.
91 a wonderful example of a successful solar power system in a location where the success of solar power has been considered doubtful.
4.2 Wind Power
Wind Energy Production Costs and Considerations
The low cost of producing wind energy is one of the fundamental reasons why it has been considered as the most important form of renewable energy moving into the twenty-first century.
In the last twenty years alone, wind energy costs have fallen by 90 percent. Measuring the cost of wind energy is a difficult task due to the high number of variables that go into its pricing.
These variables or factors are constantly changing based on the current status of wind turbines.
A sample model can be created, however, using a specific wind turbine model. This section will go over the most important variables that are considered when generating a price to produce a kilowatt per hour of wind energy. After covering these variables, specific wind turbines and their efficiencies will be examined. Based on this information, specific configurations of these turbines will be matched against conventional electricity means to show exactly how much of the power production wind energy will be able to supplement in the near to distant future.
The first set of factors is turbine specific. Such factors are the capacity of power output by the wind turbine, the speed of the wind hitting the turbine, and the physical design of the turbine. Specifically, the height of the tower, the area swept by the blades as they move, and the area that the turbine rotor covers as wind causes the turbine to spin creating energy. Specific design techniques for the blades themselves have helped to lower costs for wind turbines as well.
Designs that have increased the efficiency by which the wind itself helps the rotor to turn. The
92 factors just mentioned are considered when evaluating the costs of an individual wind turbine.
Looking at specific wind speeds and their associations with cost, we can see exactly how much it affects cost of production. For a 51 MW facility with wind speeds of 7.15 meters/sec (mps), a cost of $0.048 per kWh would be obtained. Increasing that speed to 8.08 mps would yield a cost of $0.036 per kWh. Increasing again to 9.32 mps would lower the cost even more to $0.026 per kWh.115 The wind speeds, of course would have to be constant or an average equaling these values in order for the price values to be correct. These estimates also include a tax credit that the federal government awards to individuals and groups that invest in wind farms. This obviously helps to levy the costs quite a bit. It should also be noted that forever increasing wind speeds cannot forever increase the efficiency at which wind energy is produced. All wind turbines have limits on how fast the wind can turn their rotors without damaging the blades or the rotor itself. This is described more in depth in the section of this report outlining wind turbine design. In addition to turbine limits, there are also limits as to how fast wind on Earth and in the United States can move at all. Right now, building a turbine that comes even close to these maximum sustained winds is not a feasible or useful goal. In most cases, high wind speeds are not maintained for very long periods of time due to the nature of their creation (i.e. tornado, hurricane, blizzard, etc). This is why we shall examine the locations where wind energy would be most the most economical choice considering average wind speeds as well as the more technologically based installation and maintenance costs.
Another important aspect in pricing is the amount of wind turbines in a specific wind farm. The higher the volume of wind turbines, the cheaper the cost to produce energy with that wind farm will be. This is due largely in part to operating and maintenance costs. It’s much
115 “The Economics of Wind Energy.” 1 Mar. 2002. American Wind Energy Association. 25 Jan. 2003.
93 more economical to hire a company to work on a series of turbines rather than a single turbine.
Also, transaction of energy costs is lowered when using more than one wind turbine. Energy is created by the turbines and must be sent into the electrical grid in order to be used by consumers.
For instance, the American Wind Energy Association produced a study that found a 3 MW wind project to cost $0.059 per kWh whereas a 51 MW facility would yield costs of $0.036 per kWh.
Of course, as with any other form of energy, there are much more complicated factors that go into the computation for costs incurred. The money needed to construct a wind facility is usually borrowed from a bank. Lenders in the United States still view the wind energy market as risky due to varying returns seen on wind projects. This makes it especially hard for individual investors to obtain reasonable financing packages in order to build and maintain their wind facilities. The tax credit mentioned previously does help investors, however. Currently, the federal government credits 1.7 cents per kWh produced. This applies to all generators that were constructed and operational before the year 2003. Despite this incentive, investors as well as lenders are still wary due to the nature of the credits. Since 1992, credits have been given for production of wind energy. The nature of these tax credits has been inconsistent since its implementation. The wind energy industry as a whole has been fighting to try and enable a more reliable crediting system. Currently, the wind crediting system no longer applies since it is currently the year 2003. However, industry figures were seeking an extension into 2006.
Currently, there is no federally funded credit available. Although, there are some states that have their own crediting systems, independent of any federal laws. For instance, in California, credits exist for any wind farm or solar system installed from 2001 until 2006. The exact refund associated with wind farms is $4.50 per rated watt (measured watt).116 Despite the weaker
116 “Renewable Energy Tax Credit.” 3 Mar. 2003. California Energy Commision. 5 Mar. 2003.
94 federal standards, California legislation has taken the proper steps to try and generate incentives for wind-based systems. The credit for wind turbines is only applicable for specific brand names and models specified by the California Energy Commission. An updated list is available for
Download at http://www.consumerenergycenter.org/renewable/tax_credit.html.
Wind Farm Cash Flow Model
Table of symbols used in this section
DP Down payment at time of purchase AEO Annual energy output in kWh
FTC Percentage given as a federal tax credit EC Cost of electricity per kWh
STC Percentage given as a state tax credit EIR Cost of energy inflation rate
SR Amount given as a rebate per state Y Number of years after installation of the system OMC Operating and Maintenance Costs per M Month of year when system is installed kWh in dollars OMI Operating and Maintenance Inflation Rate
This section will, in detail, examine the design and costs of several different types of wind turbines. First, an individual turbine will be examined to illustrate how an investor’s cash flow would act over time. Next, a wind farm will be examined thoroughly to show how the individual electricity user on a grid would be able to save money over time by having their energy produced by wind power. Bergey Windpower Co. designs the first two turbines examined by this report. The turbines are both horizontal axis rotors. The smaller model is the
BWC XL.1 and will be the first turbine examined. This model is made for stand-alone that produces 24 VDC of electrical current. The type of blade is a 3-blade, upwind rotor. The turbine has a rated power of 1000 Watts and a maximum power of 1600 Watts. In order for the
95 turbine to start working, the speed of the wind must be 3 meters/sec (m/s). The rated wind speed, which can be associated with the rated power, is 11m/s (24.6 mph). The maximum sustainable wind speed that the rotor can endure is 54 m/s (120 mph).
The XL.1-24 model costs $1,890.00 for the turbine itself. This price does not include the tower, which must be purchased separately. The height of the tower purchased is up to the buyer. This price ranges from $540.00 for a 9m (30ft) tower all the way to $1,640.00 for a 32m
(104ft) tower. The reason tower heights vary depends on the location where the wind turbine is installed. Wind speeds vary in certain areas from the ground to only 20 to 30 meters above the ground. Making a tower as high as 32m assures that, for some locations, the wind will yield enough energy to power the turbine. The total cost of purchase averages around $3000.00, making it a relatively affordable solution for low energy using homeowners. Relative cost comparisons to that of conventional grid electricity will be examined later in this section.
The next model is a more business-orientated model. The Bergey Excel series features both battery outputs ranging from 24 to 240 VDC as well as grid connections and is able to power an entire home at a moderate wind site. The rated power is 10kW with a rated wind speed of 13.8 m/s (31mph). This design also uses a 3-blade upwind rotor. The diameter of the rotor is
7m (23ft). The maximum design wind-speed is 54m/s (120mph).
The cost of the Excel model turbine ranges from $18,400 to $22,900. Again, the tower must be purchased separately. The common tower used for the BWC Excel is the Self-
Supporting Lattice Tower. The height of the tower ranges from 18m (60ft) to 37m (120ft). The costs for these towers ranges, respectively, from $7,000 to $13,200. This type of tower is the cheaper alternative for investors compared to other towers. This is because the tower does not have the ability to be lowered in order to install the blades as well as perform maintenance on
96 them. This makes the average cost, without installation, around $26,000 to $32,000. Obviously,
this solution is much more expensive for the common homeowner. The electricity output is
much greater, however, and can be considered for powering an entire household whereas the XL-
1x cannot. 117 This is because this particular model simply uses a larger turbine (requiring faster
winds) yielding more electricity than the smaller XL-1x model.
It’s important to note, that both Bergey models come with a vast array of design
configurations and options. The prices listed here are simply for the turbine and the tower.
Installation costs are not given by Bergey, but instead are reliant upon the dealers of the turbines
and towers. Depending on which dealer you purchase from, the price of the installation will
vary. This price also depends significantly on the location where the turbine is being installed.
This includes both terrain aspects as well as the type of average wind speeds the turbine will
realize in its location.
The design by Bergey that will be focused on is the Excel 10kW design since it has the
capability to power an entire household on its own. In order to examine the cash flow associated
with the purchase of this system, assume that the purchased price is $35,000 and that the annual
output of electricity from the system is 12,000 kWh. Let us also assume that the system was
purchased in full without having to make use of a bank loan, thus eliminating any forms of
interest charges. The cost per kWh produced is approximately $0.12. The operating and
maintenance costs are about $0.005 per kWh with an inflation rate of 3% per year. This model
does not assume any type of state tax-credit. It merely assumes a federal tax of 35% and a state
tax of 8% of the total power produced.
117 “Retail Price List: Wind Turbines.” 20 Sept. 2002. Bergey Windpower Co. 24 Feb 2003.
97 Using the given numbers, the following model will represent the current cash flow value
associated with any wind turbine installed and operated in the United States. This model was
created by Bergey and can be found on their web site. To calculate the cash flow value (CFV) in
the first year (year 0):
CFV = DP [ 1- FTC [ ( 1 + SR) + ( STC * ( 1- SR) ) ] ] Eq. 4.2.1
Where DP is the down payment at the time of purchase, FTC is the % given as a federal tax
credit, SR is the state rebate percentage, and STC is the state tax credit. To calculate the dollar
value of the energy produced (EP) per year:
EP = (AEO * ( EC * (1 + EIR ) Y - 1 ) ) Eq. 4.2.2 Where AEO is the annual energy output in kWh, EC is the electricity cost per kWh in dollars, EIR is the electricity inflation rate (%), Y is the years since installation, and M is the month of the year when the system was installed. To calculate the costs (CS) for a given instant in time: CS = (AEO * OMC ) * ( 1 + OMI ) Y – 1 Eq. 4.2.3 Where OMC are the operating and maintenance costs per kWh in dollars, and OMI is the operating and maintenance inflation rate (%). To calculate the cash flow value for each successive year using the first three equations [0.0]: Current CFV = (CFV + EP – CS) Referring back to the given numbers for a single Bergey Excel 10kW, the model, after 5 years,
would result in a cash value of ($27,506). After 10 years, it would stand at ($19,602). After 15
years, it would stand at ($10,895). After 20 years, the homeowner would finally break out of the
red realizing a savings of $726 from the time of installation as compared to using conventional
utility-based electricity. After 25 years of use, the savings would be $9,255.118 The model used in this is quite easy to see that financially, this model does make sense for investors/homeowners that are willing and able to pay the original installation fees without having to take out a loan to
118 “BWC 10 kW GridTek System Cash Flow.” Mar. 2002. Bergey Windpower Co. 26 Feb. 2003.
98 do so. This of course makes it difficult for the average homeowner to realize the same type of profit due to loan payments.
Next, we will examine a different kind of wind turbine investment. This scenario will examine the results obtained for a wind farm structure instead of an individual wind turbine. For this section, a wind farm capable of an optimal production of 25MW will be used. Since wind turbines are typically priced based on the amount of power they can produce, we will not examine specific types of wind turbines in this section. Pricing for different wind turbines varies based on a variety of variables. Since there is no way to tell exactly what the site will look like, we cannot calculate the exact costs. We can only estimate. Using our model, we will then project worse case, best case, and average case scenarios for the production of energy through our wind farm. In order to present our facts accurately, we will be graphing the values we get as well as displaying them in table format. Worst-case scenarios will make use of the minimum required wind speed required to produce energy. The best-case scenario will assume full functionality of the wind farms (theoretically 100 percent production) and the average case will use average wind speeds annually from the location of the farm. The location will be California.
The reasoning for this location is explained in the following section for Wind Farm Cost Models.
Since the companies do not list the prices for their equipment online, we will be using the
American Wind Energy Association’s estimation that the cost per kWh is around $1,000. This price simply takes into consideration the installation costs for the wind turbine. Operating and maintenance costs are not calculated into this estimation. Actual costs for wind farms are incredibly difficult to calculate based on the model and the number of wind turbines alone. “The
99 actual cost for a given installation depends on the size of the installation, the difficulty of construction, and the sophistication of the equipment and supporting infrastructure.”119
Using the same equation that we used in the calculations for the individual wind turbine, we will use the following givens to analyze an investment. The following will be the amount of energy produced for the worst, average, and best case scenarios: 20,000MW, 30,000MW, and
40,000MW. The cost of the investment will be estimated at $25,000,000 using our $1,000 per kWh estimated price calculator. There will be no loan associated with the purchase of the farm.
The total cost will be paid for at the time of purchase. This makes our calculations easier and results more meaningful since choosing an arbitrary loan amount and length could give misleading results. The other assumed values are a interest rate of 10%, a net Federal tax rate of
35%, a net state tax rate of 8%, operating and maintenance costs of $0.005 per kWh with an inflation of 3% annually, and no rebates or tax credits federally or by the state.
Figure 4.2.1 shows the total cash flow associated with our investment. This case, as previously mentioned, changes the amount of energy produced by the farm in order to calculate cash values for the worst, average, and best case scenarios.
119 “NWCC Wind Energy Series No. 11.” January 1997 No. 11. National Wind Coordinating Committee. 30 Mar. 2003.
100 Total Cash Flow - 25MW Wind Farm
$200,000,000.00
Worst $150,000,000.00 Average Best
$100,000,000.00
$50,000,000.00 Total Cash Flow Value $0.00
0 2 4 6 8 8 10 12 14 16 18 20 22 24 26 2 30
($50,000,000.00) Years
Figure 4.2.1
Looking at Figure 4.2.1, we can see that in the best case, the investment would break even after 5 years. This would help yield profits of over $150,000,000 after 30 years. In the worst case, it would take around 11 years to break even from this investment. The profits after 30 years this time would only result to about $60,000,000. Lastly, the average case would result in a break even after about 7 years and would yield a return on investment around $110,000,000 after 30 years.
These three scenarios changed the amount of energy produced as an average. This is one of the most important aspects of a wind farm that needs to be understood. Wind is not like coal or gas; it cannot consistently produce levels of electricity like the more conventional sources can.
This is why the average electrical output is what we change in this model. It shows not only that breaking even can vary anywhere from 5 to 11 years, but it also shows that even after breaking even, profits after 30 years can vary anywhere from $60,000,000 to $150,000,000. This is quite
101 a difference for sure considering that some of that will have to go back into the farm for operating and maintenance costs.
Significant profits can be made from wind farms over time. This is the driving point behind the model. Even in the worst-case scenario, an initial investment of $25,000,000 would yield profits of double the investment over a 30-year span. In the best-case scenario, the investor would see profits of over 6 times the initial investment. Granted, this is quite a long period of time. However, many investors are willing to make profits in the long run and good investors realize that profits do not always have to come quickly. The amount of money being dealt with here is in the millions, proving that any investor would walk away from this scenario happy. Not to mention, of course, the almost uncountable ways that he or she has helped to sustain the environment.
Wind Farm Cost Model
Since it is unlikely that a single wind turbine is a cost effective means of producing energy, the same model will be applied to a wind farm with 150 wind turbines in full operation.
Three different wind turbine models will be used to show how different turbine designs are, for various reasons, more cost effective than other designs. In order to choose a location for the wind farm, the average wind speeds associated with locations throughout the United States must be examined. Looking at figure 4.2.1, it can be seen that the location of the country with the most wind energy potential is the western portion of the country. The greatest potential winds exist in Colorado, Idaho and Montana. Unfortunately, the weather in these states in the winter is bitterly cold and snowy, making less than desirable operating conditions for our wind farm.
Southern California also has a high potential in a much smaller area. Since the weather in
102 southern California is typically warm year round with low average of 58 degrees F and a high average of 73 degrees F.120 The exact location of the site will be at Romero Overlook, CA, where the National Renewable Energy Outlook already deemed as a wind farm site.
Observations have been recorded there since 1981. The location can be seen in Figure 4.2.2 specified by the black arrow.
Figure 4.2.2 – US Annual Avg. Wind Power. Source: Renewable Resource Data Center (http://rredc.nrel.gov)
120 “Monthly Average San Diego, CA Temperatures.” National Weather Service Homepage. 20 Jan. 2003.
103
Figure 4.2.3 – US Wind Resource
Source: National Renewable Energy Laboratory
(http://maps.nrel.gov/images/Ressource%20Maps/windres.jpg)
As seen here, the NREL has the site classified as containing an “Outstanding” value for potential wind resource. In order to accurately compare each of the wind farm systems, charts will be setting up showing the value of the farm in dollars over time. It will be assumed that for the calculations, the average wind speed of 6 to 7 meters/sec (as seen in Figure 0.0 in Classes of
Wind Power Density key).
Examining Consumer Benefits of Wind Energy Usage
Table of Symbols Used in this Section
Ee Expense of electricity per year when Pw Price of wind-generated electricity per produced by conventional means kilowatt-hour Pe Price of conventional electricity per S Percentage of electricity in grid generated by kilowatt-hour standard means Ec Average yearly consumption of electricity W Percentage of electricity in grid generated by (kW) per household wind power R Inflation rate for electricity costs (wind Y Number of years after installation of the and standard electricity) system
*The term “standard energy” refers to energy generated by oil, coal, natural gas and other sources currently used in the modeled electrical grid.
104 The motivation behind the following mathematical models is to create simple variable
models that illustrate potential savings for consumers tied into a grid containing wind-generated
power. In order to make the model simple as well as accurate, we took into consideration only
those variables that have a profound and direct impact on energy expenditures. The most
important consideration here is, of course, the cost per kWh of standard electricity and wind-
generated electricity (Pe and Pw respectively). These costs must be multiplied by the average
amount of energy used per year by the model household (Ec) in order to generate the gross cost
of electricity for one year of usage. However, the cost of electricity rises with the inflation rate
(R). By multiplying by the term (1 + R)Y-1 (the standard form for calculating yearly inflation),
we are allowing the model to project rising energy costs and thus be applicable for the prediction
of costs over a given number of years. In our second model, Figure 4.2.3, we take into
consideration the infusion of wind energy into the grid. The variables used in the first equation
are also incorporated into the next model. When an energy source is fed into an electrical grid, it
contributes a certain percentage of the energy into that grid. However, that percentage is
impossible to determine exactly. For the purpose of our model, we assumed that 10% of the
electrical grid would be supplied by wind power and 90% by standard electricity. Because wind
generated energy and standard generated energy each have different costs to the consumer, we
must incorporate these grid percentages (S for standard, W for wind) to calculate the cost
contributed by each form of energy. We did not consider variables outside of those in our model for several reasons such as increases in cost due to unexpected factors involving damage to the source of the energy; a rise or fall in the inflation rate as a result of economic conditions, etc. In the long term, these costs are negligible as they are highly unlikely. They would only complicate the model and cloud the influences applied by the more important factors. Also, such variables
105 are extremely difficult to estimate and furthermore predict. Therefore, including them may not
only skew the results, but may also produce completely inaccurate results. Such variables would
also interfere with our goal of making a simple and understandable model because it would
inaccurately depict the final results we produce.
The following information will examine the effect wind energy will have on the average
home entity. In our examination, the average cost of electricity per kWh is estimated at
$0.125.121 In order to account for fluctuations in the market, we will also model best and worst
case scenarios. This first value is assuming that the means of producing electricity are
conventional turbine generated means such as gas, coal, or nuclear turbines. The second given
value for our model is the average consumption of energy by the home user. This value is
estimated at 6450 kWh (or 6.450 MWh) per year.122 In the first model, we will assume that the amount of energy consumption does not change for our best, worst and average case scenarios.
The value that will change in the model will be the rate of inflation on the standard price of electricity. Our average case assumes an inflation rate of 3 percent annually.123 The best case assumes an inflation rate of 2.5 percent and the worst case an inflation rate of 3.5 percent. The equation used to calculate the cost is:
Y-1 Ee = Pe * (Ec * (1 + R) ) Eq. 4.2.4
Where Ee is the expense of electricity per year when produced by conventional means, Pe is the
price of energy per kWh, Ec is the average amount of energy consumed by a household (kW) per
121 “Electricity Price Forecast.” 19 July 2002. California Energy Association. 28 Jan. 2002.
106 year, R is the inflation rate for electricity costs in kWh per year (for standard and wind generated sources), and Y is the number of years from the first year the consumer starting receiving electricity. Figure 4.2.4 illustrates the three scenarios:
Yearly Per Capita Cost - Standard Electricity Sources
2000
1500
1000 Dollars ($)
500 123456789101112131415161718192021 Expense (AVG) Years Expense (BEST) Expense (WORST)
Figure 4.2.4 – Yearly Per Capita Cost via Standard Electricity Sources
As you can see in Figure 4.2.4, the cost in year one ranges from $750 to almost $2000 a year in
20 years time.
We will now examine the same energy model with wind energy factored in as 10 percent of the energy production. The following equation will be used to calculate the cost of electricity:
Y-1 Y-1 Ee = (Pe * ((S * Ec) * (1 + R) )) + ((W * Pw) * (Ec * (1 + R) )) Eq. 4.2.5
107 Where the givens for the first part are the same as equation 4.2.4 except for S, which is the
percentage of electricity used by standard electrical means. The second part of the equation has
Pw, the price of wind energy per kWh in dollars and W is the percent of power produced by wind
energy. For this particular graph, the percent of standard power used was 90 percent and the
percentage from wind power is valued at 10 percent.
Yearly Per Capita Cost - Incorporated Wind Energy 2000
1500
1000 Dollars ($)
500 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Expense (AVG) Years Expense (BEST) Expense (WORST)
Figure 4.2.5 – Yearly Per Capita Cost via Standard and Wind Energy Sources
Looking at this graph, we can see that the average cost per household is again $750 in the first year. Over time, however, the average cost will only raise to around the $1500 mark. This means that incorporating a mere 10 percent of renewable energy into the consumer’s individual monthly bill will generate savings of around $400 per year by the 20 year mark.
In order to better illustrate the savings over time, we will now illustrate how much money is saved per year by using a bar chart. The chart will graph the yearly costs with and without
108 wind energy side by side in order to give a clear picture as to exactly how much money is being
saved per year with wind energy accounting for 10 percent of the total energy production.
Comparison of Expenses
2000
1500
1000 Dollars ($)
500 1 2 3 4 5 6 7 8 9 101112131415161718192021 Years Expense Without Wind Expense With Wind
Figure 4.2.6 – Comparison of Expenses (With and Without Wind Energy)
The bar char shows that at year one, the savings will be small, only about $50. By year 20, however, these savings are clearly in the $300 to $450 range. Over time, the savings for the household will increase exponentially as individual savings per year increase. The following chart illustrates how much money will be saved in total at the end of each calendar year.
109 Compounded Yearly Savings
3000.00
2000.00
1000.00 Dollars ($)
0.00 123456789101112131415161718192021 Savings Savings (BEST) Years Savings (WORST)
Figure 4.2.7 – Compounded Savings Per Year
Figure 4.2.7 shows that the household will save about $1500 over 20 years at the worst. In the best case, the savings would be just over $3000. Either way, the household is the one experiencing the benefits of having their power generated by wind turbines instead of conventional energy. This particular model, of course, does not take into consideration any type of environmental savings that would result from using wind turbines instead of petroleum or nuclear powered turbines.
Case Study - Cape Wind Project
In order to better understand the decisions and considerations of developing a wind farm,
we will now discuss an existing wind farm project that is underway off the coast of Cape Cod,
Massachusetts. By examining an existing wind project, we will be more capable of developing a
wind farm model of our own, which we can use as a tool to illustrate the benefits and detriments
110 of a wind farm. The Cape Wind Project is a full-scale development project that hopes to have a
working wind farm for the users of the New England electrical grid by the year 2005.
In order to develop an effective and economical wind farm, several geo-topographical
occurrences must be present. The region to be developed must have a wind power class of at
least 3, and the land must be highly exposed to the wind. Five miles of the shore of Cape Cod,
Massachusetts there is a wind power class of 7, with almost 100% exposure to the wind. This
makes this area ideal for a wind farm. That is why the Cape Wind Project aims to have a fully
operational wind farm by 2005. The farm is to be built in Horseshoe Shoal, about five miles off
the coast of Massachusetts. The farm will consist of 170 wind turbines spread over a five by five
mile area (25mi2). The project goal is to power approximately 500,000 homes and reduce the oil import by 113 million gallons per year. This wind farm will be able to input into the electrical grid in the very populous northeast. Currently, 7-14% of electricity in Massachusetts comes from renewable sources. The vast majority of that percentage is hydroelectric power, with the rest being waste-to-energy and landfill gas facilities. The average household consumes about
6.45 megawatt-hours per year. The Cape wind farm will produce an estimated 1,491,384 megawatt-hours per year. Due to the complexity of the New England power grid, the absolute destination of the electricity generated by the farm is unknown. However, the majority of the power will stay on Cape Cod and will contribute in some way to the electricity of upwards of a half million homes.
A primary motivation behind the Cape Wind Project is environmental awareness.
According to capewind.org, the project will protect the environment in the following ways: it will eliminate 4,642 tons of sulfur dioxide, 120 tons of carbon monoxide, 1,566 tons of nitrous oxides, more than a million tons of greenhouse gases, and 448 tons of particulates from being
111 dumped into the air. While wind produces virtually no harmful gases, the burning of coal can produce upwards of 1.5 million tons of carbon dioxide in one plant. Natural gas and oil also produce extremely high carbon dioxide levels. Carbon dioxide is the primary contributor to global warming, thus the Cape Wind Project hopes to reduce the damage we are causing to the atmosphere.
The Cape Wind Project also made it a priority to not invade or harm the wildlife of Cape
Cod or dampen the fishing industry. The wind towers are to be placed 1/3 to ½ of a mile apart, thus allowing most fishing vessels plenty of room to operate. Also, this will not greatly affect the natural habitat of the regional aquatic animals, including large species such as whales and dolphins. The wind turbines will also pose very little threat to the bird population in the area
(many environmentalist fear bird flock collisions with turbine rotors). In no existing wind farm has there been any impact on bird populations in the area. As a result of the very small land area being taken up by the farm, no bottom dwelling animal species will be affected by the construction of the turbines.
A major benefit of the Cape Wind Project will be the long-term economic savings. The cost of the wind itself is free, thus the suppliers of the wind energy will be able to carry long- term fixed-rate contracts with energy purchasers and distributors as opposed to the variable contracts endured by suppliers of standard energy sources. The exact cost per person attached to this farm is extremely difficult to calculate as a result of the complex nature of the electrical grid.
However, due to the variable and ever-increasing price of electricity by other means, the wind project is sure to save the average home exceptional amounts of money. This is especially true in the northeast, especially Massachusetts, where electricity prices are among the highest in the nation. The price for electricity has risen nearly exponentially in the last thirty years, whereas
112 the cost of wind energy has gone down by more than 80% in the same time. These costs are of particular concern to project workers due to the increasing electricity use in New England. Since
1970, the usage of electricity has doubled. The recent explosion of telecommunications devices and improved manufacturing equipment is contributing to an even steeper rise in electricity use.
The growing population also drives this problem. It is estimated that by the end of this decade, there will be a 17% increase in electricity usage in New England. That drastic increase in usage coupled that with the extremely high electricity prices will generate overwhelming long-term costs. The advantage of having a “free” fuel source is very easy to see here. Buyers on the New
England Independent System Operator market (ISO ~ this is the market that governs the purchasing of electricity) will be able to make long-term contracts with the wind power suppliers. There will be no fuel cost to the supplier, so the contract will have extremely low costs compared to typical energy sources.
The construction of the wind farm is based off of previously existing wind farms. The rotor blades are to be made from fiberglass mats filled with polyester. The towers will be constructed of steel plates rolled into conical sections. The towers will range in height anywhere from 65-100 feet, depending on the dept of the water they are to be placed in. The nacelles, which contain the primary components of the wind turbine, are constructed from highly specialized metals such as steels that can withstand extreme forces. All of these components, including components of the foundations, will be moved to the site by ship. A difficult part of the construction process is laying the cables, which will carry the electricity. The wind power will connect to the grid at NSTAR Electricity in Yarmouth, MA. The cables will be laid under roads and will require a great deal of standard construction techniques. The underwater cables must be laid using a special process where high-powered jets fluidize a pathway into which the
113 cables are laid. The cables will be buried several feet once the sediment settles again. This process is minimally invasive and the surface of the ground returns to normal almost immediately. When it is time to actually assemble the turbines on site, monopole foundations will be laid. They will be between five and six and a half meters across and will weigh between
250 and 350 tons. These foundations will be laid approximately 85 feet into the seabed. The towers, nacelles, and rotors can then be placed on the foundations to complete the construction.
Once the turbine is built, it is connected to the electrical service platform (ESP), which serves as the main connection point and the offshore maintenance facility. From there, the undersea cables run to Yarmouth, and the process is complete.124
The stipulations considered by the Cape Wind Project provide us with a working example of the many aspects and decisions involved in creating an effective wind farm. The construction and site development in the Cape Wind Project differs from most projects in that the development takes place mostly in water. However, many aspects of the CWP (i.e. turbine placement and spacing, grid connection, potential, environmental considerations, etc.) can be applied in developing our own working model of a wind farm.
124 Cape Wind Organization. Home Page. 03 Feb. 2003.
114 5.0 ENERGY POLICY
5.1 US National Energy Policy - Review
Overview Facing ever-growing energy crises in the United States, President George W. Bush instituted the National Energy Policy Development Group (NEPD) headed by Vice President
Dick Cheney. The group was advised to “develop a national energy policy designed to help the private sector, and, as necessary and appropriate, State and local governments, promote dependable, affordable, and environmentally sound production and distribution of energy for the future.”125 The Bush administration was facing potentially severe energy shortages in the United
States. This was clearly evidenced by the widespread blackouts in the state of California. The recommendations of the NEPD were focused around fostering an environment of growth and expansion in the US energy infrastructure that would ease the growing need for energy in the country. The group considered many options including the expansion and modernization of current energy sources (i.e. oil, natural gas), the fortification of nuclear power, and the implementation of renewable energy sources.
The primary proposal of the NEPD was based on the advancement of domestic energy sources already in widespread use, forecasting: “The day they (renewable and alternative fuels) fulfill the bulk of our needs is still years away. Until that day comes, we must continue meeting the nation’s energy requirements by the means available to us.”126 The need for new and efficient electricity plants is of great concern to the NEPD. It is the opinion of the group that a
125United States. National Energy Policy Development Group. Report of the National Energy Policy Development Group. Washington: GPO, 2001 126 Ibid.
115 significant portion of future electricity needs will be derived from expansion of natural gas facilities in the US. They propose developing new, gas-based power plants. The NEPD is also a strong proponent of furthering the development and implementation of nuclear facilities across the country. “This power source (nuclear), which causes no greenhouse gas emissions, can play an expanding part in our energy future.”127 The sponsoring of these new electricity plants is the central tool for meeting the US’s growing energy needs according to the NEPD.
The secondary proposal of the NEPD involves the updating of current domestic oil and gas lines in the country in order to increase the efficiency of current systems. They propose that newer oil and gas lines would allow for more usage of these fuels:
Our current, outdated network of electrical generators, transmission lines, pipelines, and refineries that convert raw materials into usable fuel has been allowed to deteriorate. Oil pipelines and refining capacity are in need of repair and expansion. Not a single major oil refinery has been built in the United States in nearly a generation, causing the kind of bottlenecks that lead to sudden spikes in the price of gasoline.128 By furnishing the country with newer oil
(and gas) pipelines and refineries, we will increase the flow of these resources and thus reduce the potential for shortages. By taking advantage of developing technologies, the efficiencies of these systems can be dramatically increased. Over the past thirty years, the ratio of domestic oil used to foreign oil used has been shifting heavily to foreign oil. The intention of the NEPD is to bolster domestic oil consumption and drive the price of oil down.
A tertiary proposal of the NEPD involves renewable energy sources and their increased implementation in the US. In an aforementioned statement, the NEPD does not feel that widespread implementation of renewable energy sources is feasible in the coming years. They
127 Ibid. 128 Ibid.
116 do, however propose an increase in several renewable energy sources. The group puts forth
biomass as its primary renewable donor. It can be applied without geographical limitation and
poses fewer economical questions than other renewable sources. The NEPD is also a strong proponent of hydropower. However, there is very little room to expand this energy source as most acceptable bodies of water have been tapped. The group also recognizes other renewable sources such as geothermal, solar, and wind. They do propose usage of these sources, yet they do not feel they can be applied for widespread usage and their economic cost may be great.
Though they note the potentially high costs of renewable sources, they recognize that increased technological advances in these areas can drive costs down and make these sources more accessible.
Analysis The goal of the NEPD was to create a policy that would be comprehensive and address
the present and future energy needs of the United States. Though their proposal has the potential
to keep domestic oil prices down and provide more accessible energy to face the current energy
shortages, the proposal fails to sufficiently handle the long-term energy needs of the United
States. The proposed amendments to our energy infrastructure have the potential to compound
the energy crisis for future generations as well as generate more environmental concerns.
The primary proposal of the energy plan calls for the addition of many new power plants
in the United States. Gas-based power plants generate many greenhouse gasses that ultimately
contribute to global warming thus increasing the need for new energy sources. Also, the
proposal to expand the nuclear facilities in this country is potentially dangerous both socially and
economically. Nuclear power plants, no matter how relatively clean and efficient, generate large
amounts of toxic waste. The removal of nuclear waste has already been a problem in the
117 country. Increasing this waste adds to the damaging effects it has on the environment and the habitat of indigenous flora and fauna. More importantly, nuclear waste is carcinogenic and the improper disposal of such waste can increase the potential of harm to local people.
Another proposal of the group is to expand the domestic oil and gas facilities to increase the flow of energy to areas in need. Theoretically, this proposal can appease current energy shortages such as those seen in California. The price of oil could potentially come down with increased domestic contribution. Here, the group fails to address long-term energy concerns.
The supply of gas, and to greater extent oil, is extremely limited. Increasing their consumption speeds the country and the world toward a situation where we have completely exhausted those natural resources. Considering the limited contribution the NEPD expects from renewable energy sources, this situation could be disastrous.
The limited role the NEPD puts forth for renewable energy sources is inadequate in many ways. The primary source of renewable contribution comes from biomass. The amount of biomass needed to create substantial energy breeds a major problem with that system. Though biomass is renewable, biomass can be used at a greater rate than it can be renewed. Biomass has the potential to contribute to our energy needs, however, it cannot be the primary renewable source. The NEPD cites geographical and economical limitations as a reason to limit the usage of wind and solar power. However, a large portion of this report handles these potential limitations and it is the opinion of this group that wind and solar power can and must be incorporated on a large scale to adequately handle our future energy needs.
The energy plan put forth by the NEPD will not allow for sufficient energy production in the future. Also, failure of the group to address the limited supply of current energy sources and the potential socioeconomic side effects of their use indicates an incomplete and narrow energy
118 policy. The aim of this report has been to address the questions surrounding the potential energy crisis. We have compiled our own energy policy based on the dramatic need for widespread implementation of renewable energy sources (wind and solar). Allowing the advancement of truly renewable sources of energy can safeguard our country from facing disastrous energy shortages when we exhaust out current energy resources.
5.2 Policy Implementation
There are two major upcoming problems associated with the upcoming energy crisis.
The first problem is the depletion of the world’s petroleum supply. The other problem is the environmental affects that are associated with today’s primary energy sources. Not only does the use of petroleum as a source of energy have limitations on the time frame for usage, it is also an extremely hazardous to the environment. The principal concern of the upcoming energy crisis is what the United States does when the petroleum supply finally runs out. Currently, the United
States depends on petroleum to account for 39% of today’s energy needs.129 In order to avoid a disaster when the petroleum supply runs out, the United States must create and follow an energy policy that will gradually transfer all the current petroleum energy sources to alternative energy sources.
This energy policy will incorporate the increase in efficiencies of devices in the market today. The implementation of renewable energy sources like Solar and wind power will also help to drastically decrease our dependence on petroleum. In order to decrease the amount of energy consumed by Americans, the efficiencies for many of the products in the market today
129 “Country Analysis Brief: United States of America.” 13 Nov. 2002. Energy Information Administration. 02 Mar. 2003.
119 need to be increased. Many companies have already begun to increase the efficiencies of these
products, but these products still consume too much energy. Continual increases need to be
made in order to decrease the overwhelming amount of energy consumed by these products,
especially motor vehicles. Solar and wind power are by far the most beneficial of all other
alternative energy sources. Solar and wind power are the cleanest, most abundant, and most
reliable renewable energy sources available today and they have the greatest long term benefits
out of any other alternative energy sources.130 If implemented, we feel this energy policy will ensure a prolonged lifetime for our petroleum supply and complete transformation to alternative energy sources by the time our petroleum supply runs dry.
There is an ever growing concern for our environment due to the millions and millions of tons of pollution that is emitted each year. The Environmental Protection Agency (EPA) has estimated that 82% of today’s pollution comes from burning fossil fuels in order to produce electricity and power our cars.131 The toxic fumes that are emitted from power plants contain
many different kinds of pollutant chemicals. Chemicals such as Carbon Dioxide, Nitrogen
Dioxides, Sulfur Dioxide, benzene, perchloroethlene, and methane chloride contribute to the
creation of acid rain, global warming, and many negative changes to our climate. Some
chemicals damage the environment more than others, but they all contribute to unhealthy living
conditions.132 If we were able to eliminate a very large portion of pollution emitted today, then
we would be able to stop or maybe even retract the ongoing changes to our environment and
climate.
130 “Development of Photovoltaics.” Jan. 1997. National Renewable Energy Laboratories. 21 Nov. 2002.
120 Toxic air pollutants such as benzene, perchloroethlene, and methylene are just some of the many toxic air pollutants. Toxic air pollutants can be found in the air, deposited on soils, or even found on the surface of water. According to the Environmental Protection Agency, some of these air toxins are released naturally from volcanic eruptions and even forest fires, but the amount of air toxins released naturally are offset naturally unaffecting the quality of life.
However, a large majority of the air toxins released today are the result from human-made sources. Air toxics are known or suspected to cause cancer or other serious health effects as well as cause unfavorable environmental and ecological effects. Prolonged exposure to sufficient concentrations of air toxics significantly increases the chance of getting cancer or experiencing other serious health effects. Some of these serious health effects can include: damage to the immune system, neurological, reproductive, developmental, and respiratory problems. Air toxics even impact the environment. Animals as well as humans can experience the same types of health issues. The EPA illustrate that numerous studies show that deposited air toxics contribute to birth defects, reproductive failure, disease, decreased fertility, decreased hatching success, damaged reproductive organs, and even altered immune systems. The National Toxics Inventory
(NTI) estimates that 3.7 million tons of air toxics are released every year. If the amount of air toxics released per year is not reduced, then human kind will continuously see damage to the environment and the ecological system as well as increase the number of serious health effects per year.133
Power plants emit a large majority of these kinds of pollutions. Some pollutants include
Sulfur Dioxide, Carbon Dioxide, and Nitrogen oxide. These three pollutants also contribute to health effects and to many of the changes in the climate. Sulfur Dioxide is formed when a fuel
133 “Toxic Pollutants.” 29 Mar. 2002. Environmental Protection Agency. 19 Jan. 2003.
121 containing sulfur is burned (mainly coal and oil). The highest concentrations of Sulfur Dioxide are located near large industrial facilities, which typically is not too far from residential areas.
The health effects from Sulfur Dioxide include breathing, respiratory illness, alterations in lungs defenses, and aggravation of existing cardiovascular disease. Sulfur Dioxide is the reason why there are so many asthmatics in the world today. Sulfur Dioxide and Nitrogen Dioxide are the major components involved with the creation of acidic deposition, also known as acid rain. The effects of acid rain will be discussed a little later. Sulfur Dioxide is also a major contributor to the creation of PM2.5, which the EPA claims is a major concern to health as well as the main pollutant that impairs visibility.134
Another pollutant emitted from power plants and automobiles is Nitrogen dioxide.
Nitrogen Dioxide is one of the pollutants that contribute to the creation of smog and haze.
Nitrogen Dioxide is the result from high-temperature combustion processes coming from many of today’s power plants. The high temperatures in the summer would explain why smog and haze is thicker during the summer months. The health issues correlating to Nitrogen Dioxide emissions are irritated lungs and lower resistances to respiratory infections such as influenza, which is a highly common illness seen nowadays. Exposure to higher concentrations of
Nitrogen Dioxide than found in regular air has been suspected to increase the number of cases of acute respiratory disease found in children. Nitrogen Dioxide also has a negative effect on the environment. Emissions of Nitrogen Dioxide have been known to affect terrestrial and aquatic ecosystems. Nitrogen Dioxide is also associated with the increasing growth of algae in many streams and lakes resulting in unhealthy or toxic living conditions for fish. Since fish are at the lower portion of the food chain, many species use fish as a food source. The fish can carry the
134 “Sulfur Dioxide: SO2.” 29 Mar. 2002. Environmental Protection Agency. 19 Jan. 2003.
122 toxins from themselves to their predator and so on up until the top of the food chain. The toxins
that began with the algae causing unhealthy living conditions for the fish could climb the food
chain and carry the affects from that toxin to all the species up on that food chain. Even though
high quantities of Nitrogen Dioxide are harmful to health and living conditions, it is also one of
the major components that go into producing our protective ozone layer. However, it is the
excessive quantities of Nitrogen Dioxide that are harmful and not the small quantities that go
into making the ozone.135
When Nitrogen Dioxide and Sulfur Dioxide combine with water, oxygen, and oxidants in
the atmosphere, acid rain is the result. According to the EPA, electric utility plants that burn
fossil fuels in order to generate their electricity produce 70% of the total Sulfur Dioxide
emissions and 30% of the total Nitrogen Dioxide emissions that are produced per year. As these
emissions increase, the amount of acid rain formed in the atmosphere will gradually increase and
the overall affect from acid rain will gradually grow worse. Along with the health concerns
relating to exposure to Sulfur Dioxide and Nitrogen Dioxide, the environment is affected by the
acid rain raising acid levels in many lakes and streams and damaging trees in Mountains and in
areas at high elevations.136 The daily intake of water is essential to the survival of many species
today. As the acid levels in the water increase, the quality of life in these areas begins to suffer
as disease and illness rises.
Carbon Dioxide is another pollutant that is emitted as a result of fossil fuel combustion
from power plants and automobiles. Carbon Dioxide is the major component that causes the
greenhouse effect. As the suns energy is radiated off the Earth and back into space, the
135 “Nitrogen Dioxide: NO2.” 29 Mar. 2002. Environmental Protection Agency. 19 Jan. 2003.
123 greenhouse gases, such as Carbon Dioxide, methane, and nitrous oxide, trap some of this heat
energy keeping the earth at a comfortable temperature of 60ºF on an average. The greenhouse effect is what keeps the Earth warm while the sun is no longer shinning on the Earth. Without the greenhouse effect, it is almost impossible for any living organism to survive the tremendously cold evenings that would occur. However, excessive amounts of Carbon Dioxide will increase the greenhouse effect causing the scenario that is known as Global Warming.
Global Warming raises the average temperatures, alters precipitation patterns, and raises sea levels. The overall climate of the Earth will change due to substantial excesses of Carbon
Dioxide. Plant respiration and the decomposition of organic matter release ten times the amount of Carbon Dioxide than human activities release. However, before the industrial revolution began, there was a perfect balance between the Carbon Dioxide that retains the heat and the
Carbon Dioxide that is absorbed by terrestrial vegetation and the oceans. According to the EPA,
Carbon Dioxide levels have increased nearly 30%, methane concentrations have more than doubled, and nitrous oxide concentrations have increased by about 15% since the industrial revolution began. The enormous increases in the major greenhouse gases have offset this balance, retaining more heat than reflecting. As a result, the surface temperatures of the world have increased by about 0.5-1.0ºF. To get an idea of how much of an impact global warming has had on the climate in the US, the 20th century’s ten warmest years have all occurred in the last
fifteen years of the century, a phenomenal statistic. The EPA indicates that the snow cover in the
Northern Hemisphere and the floating ice in the Arctic Ocean have decreased due to the increase
an increase in global temperature. As a result from all of the additional water from the melted
snow and ice, the sea levels have risen somewhere between four and eight inches globally, a
remarkable increase.137 Evaporation will increase due to warmer temperatures causing more
137 “Global Warming – Climate.” 31 Oct. 2002. Environmental Protection Agency. 21 Jan. 2003.
124 precipitation and drier soils. The number of intense rainstorms will increase per year, resulting
in an increase in the number of flash floods due to the lack of moisture in the soil. Flash floods
can damage and/or destroy some of our crops depleting our overall food supply. At this point in
time, some areas of the United States receive more rainfall than others. A change in climate and
precipitation patterns would alter the locations of the areas with high precipitation and low
precipitation resulting in a change in crop compatibility in certain areas.138 A part of the country
that receives large amounts of precipitation per year containing lots of plant and wildlife could
receive minimal amounts of precipitation per year due to a change in climate. That part of the
country could turn into a baron wasteland due to the lack of rainfall to keep the organisms in the
area alive. A change in climate will affect the whole world and not just the United States. If
global warming is allowed to continually increase as it has up until the Clean Air Act, some
major climate issues will be the result and our overall way of life will be affected.
The United States has made an effort to change the current trend that would lead us
inevitably to a change in climate. The Clean Air Act was amended in 1990 to control the amount
of emissions emitted by power plants, automobiles, and many other industries that emit
pollutants. Basically, the Clean Air Act states that a power plant must not operate if they cannot
remain under the allowable emissions. The U.S. Geological Survey did a study in 1996 to see if
there were any improvements in the environment since the Clean Air Act has been implemented.
The study showed that the gradual reduction in emissions for Sulfur Dioxide and Nitrogen
Dioxide resulted in less acidic rain.139 As these emissions are gradually reduced per, there will
be less and less acidic rain and the global warming effect will gradually reduce. As
125 concentrations of these pollutants reduce, there will be less smog, improvements in public health,
and better water quality in lakes and streams.
The Clean Air Act is one good way to reduce the amount of emissions that power plants
and many automobiles produce per year. The Clean Air Act does control the amount of
emissions released each year, but there are still a lot of pollution being released. Instead of
controlling the amount of greenhouse gases being released per year, simply stop releasing these
pollutants. The implementation of a solar and or wind power system will do the trick. In fact,
these renewable energy systems are silent and non-polluting.140 According to the EPA,
implementing a 25MW solar or wind power system in California will greatly reduce the amount
of emissions released per year. A similar 25MW power plant that burns fossil fuels would
release 20,476lbs of Nitrogen Dioxide, 512lbs of Sulfur Dioxide, and 64,193,828lbs of Carbon
Dioxide whereas a solar power plant will release none of these emissions. The EPA states that
the Carbon Dioxide emissions saved by implementing a system of this magnitude are equivalent
to 80,242,284 miles driven in an average passenger car and the Carbon Dioxide absorbed by
approximately 9,041 acres of trees in one year. By implementing the 25MW solar or wind
power system, we avoid tons of emitted pollutants and reserve the additional 9,041 acres of trees
to help further reduce the already high concentrations of Carbon Dioxide.141 The
implementation of these systems will help avoid continual damage to the environment and
completely altering our climate. As more and more wind and solar power systems are
implemented rather than pollutant emitting power plants, the environment will gradually grow
better resulting in healthier living conditions.
140 “Development of Photovoltaics.” Jan. 1997. National Renewable Energy Laboratories. 21 Nov. 2002.
126 The greatest concern and greatest reason for the search of alternative energy sources is
due to the limited supply of petroleum. This problem arises from the phenomenal amounts of
petroleum consumed by Americans and other countries worldwide each year knowing that the
petroleum supply will not last forever. The United States currently imports more petroleum than
Denmark, Finland, France, Germany, Greece, Italy, Norway, Spain, and Sweden all combined.
All of these countries are small countries compared to the United States, but the mere fact that
the United States consumes more petroleum than nine countries combined indicates that an
incredibly high amount of petroleum is being consumed. In the 1950’s, the United States
discovered a petroleum deposit containing approximately 260 billion barrels of petroleum. This
discovery placed the United States as one of the leading petroleum producers in the world
trailing only Saudi Arabia. With the 260 billion barrels of petroleum, the United States was able
to sell enough of it to supply half of the world’s petroleum demand and did so for many years.
However, the United States eventually exported and consumed so much petroleum in that fifty-
year time span that approximately 45% of this petroleum was left. By this time, the United
States was importing more than half of the petroleum it consumes due to the decrease in
petroleum production as a result of the diminished supply. Now that the petroleum supply
controlled by the United States has reduced significantly, Middle Eastern countries would
eventually have complete control over petroleum prices, which have led and will lead to many
more conflicts with some of the Middle Eastern countries.142
In the year 2000, 7.21 billion barrels were consumed by the United States alone.143 This number has rapidly increased over the years and the Energy Information Administration (EIA)
142 Alternative Energy Institute, Inc. Home Page. 20 Mar. 2003.
127 projects that the demand for petroleum will continue to increase up until at least 2025. With this
prediction in mind, the EIA generated Figure 5.2.1 showing the history and predictions of
Petroleum consumption between the years of 1970 and 2025.
144 Figure 5.2.1
The overall trend of petroleum consumption is expected to continually increase at a consistent
rate up until at least 2025. The EIA predicts that the 19.7 millions of barrels consumed in a day
in 2002 will increase at a rate of 1.7% per year reaching up to 29.17 million barrels per day by
the year 2025.145 The consistent growth of fossil fuel and petroleum consumption will only lead
to more serious problems in the future. The more we use petroleum as an energy source, the
deeper the hole we dig ourselves into and the tougher it will be to dig ourselves out when the
petroleum supply begins to reach critically low levels. This trend of consumption needs to make
144 “Annual Energy Outlook 2003 With Projections to 2025.” 27 Jan. 2003. Energy Information Administration. 22 Mar. 2003.
128 a turn around in the very near future in order for the United States to be at a prosperous
economic stand point when the world’s petroleum supply is at this critical level.
In order to have little complication when the petroleum supply does run out, the United
States has to make the transformation to alternative energy sources a gradual one. To help
realize an approximate time when the petroleum supply will run out, one must determine the
approximate peak point of petroleum production. This peak is known as Hubbert’s peak.
Hubbert’s peak is utilized for explaining the supply of finite resources; in our case, petroleum is
our finite resource. For any finite resource, production will start at zero, which will eventually
rise to a peak that will never be surpassed, and then production will gradually decrease until the
finite resource is gone. Many different sources have indicated that the peak point will occur
somewhere between 1990 and 2010. This large deviation is largely due to the unknown amount
of recoverable petroleum on the planet. There are still some petroleum deposits in the Earth that
has not been discovered yet that will prolong the lifetime of our petroleum supply. This should
not help to substantially increase the length of time, however.146 Since we cannot accurately
determine how much petroleum we have left, an unknown rate of decline will result after the
peak in production has been reached. The steeper the decrease in petroleum production, the
faster we will have to come up with alternative energy sources to compensate for the lost
petroleum production, meaning more money would have to be spent each year.
It is impractical to think that the amount of petroleum production will keep increasing
until there is no more reachable petroleum on the planet left. However, as the overall amount of
petroleum left on Earth decreases, it will become more difficult to find the remaining petroleum
146 “The Hubbert Peak for World Oil.” 12 Feb. 2001. EcoSystems. 19 Mar. 2003.
129 on Earth. This will result in a smaller amount of petroleum produced each year.147 This
declining slope after the peak in petroleum production can be demonstrated by the trend of
annual petroleum production by the United States between 1986 and 1999. Figure 5.2.2 below
was generated from the data provided by the EIA and Department of Energy (DOE) between the
years 1986 and 1999.
Annual US Oil Production: 1986 - 1999
3.4 3.2 3 2.8 2.6 2.4 2.2 2 Billions of Barrels per year
8 9 0 1 2 3 86 87 8 8 9 9 9 9 9 9 9 9 1 1 1 1 19 19 19 19 1994 1995 1996 1997 1998 1999 Year
Figure 5.2.2
As you can see from the figure above, the United States surpassed their peak production mark in their petroleum supply years before 1986, which is indicated by the continually decreasing amount of petroleum production in the fourteen-year span. In these fourteen years, the annual
United States petroleum production decreased from 3.17 billion barrels per year to 2.15 billion barrels per year (a 33% decrease in production).148 The United States consumed and exported so
147 “The Hubbert Peak for World Oil.” 12 Feb. 2001. EcoSystems. 19 Mar. 2003.
130 much of their supply in the beginning years of production that once they reached their peak of
production, the petroleum production dropped by one-third in a manner of fourteen years.
The world’s petroleum supply is expected to act in the same manner as the United States
petroleum production did. However, there is no telling how fast the world’s petroleum
production will decrease once the peak of the world’s petroleum production has been reached.
Once this peak has passed, the petroleum production will decline, but the actual rate of this
decline can only be estimated. The rate of decline depends entirely on the point in time when the
peak occurs and the amount of petroleum left in the world. Following the trend in petroleum
production can closely approximate the time in which the petroleum production peak occurs, but
the remaining amount of petroleum in the world is still unclear. As a result, we can only
estimate how fast or slow this rate of decline will be. Figure 5.2.3 below shows a number of different paths the petroleum production curve can take.
Figure 5.2.3
131 As you can see from the figure above, the longer it takes to reach the peak point, the faster the
production curve will decline. If the petroleum production does keep increasing by 1.7% up
until the year 2025, then we should expect to see the petroleum production curve decrease at a
furious pace. As we begin to run out of our petroleum supply, the remaining petroleum deposits
will be much harder to find and reach than today’s petroleum deposits.149 As the petroleum gets
tougher and tougher to find and extract, the amount of petroleum production will decrease each
year as a result. In order to make the transformation to alternative energy sources easier, we
need to slow the petroleum production so we can have more control over the petroleum
production in the future.
The United States will have to keep up with the eventual decline in petroleum production.
If we were to continue to ignore the problem and allow our petroleum consumption to
continually increase year after year, then as soon as petroleum production begins to decline,
more and more people will begin to fight over the smaller amounts of petroleum. As a result, the
prices for petroleum will skyrocket and numerous conflicts will occur due to the small amount of
available petroleum, both of which are very disagreeable.150 To avoid a severe energy crisis in
the future, we would have to put at least enough money into the production and discovery of
newer and more efficient alternative energy sources to compensate and make up for the lost
energy from petroleum as the petroleum production decreases each year. However, more money
must be allocated for the additional energy consumption each year.
Another issue associated with the supply of petroleum is the increasing demand for
energy. In order to achieve a successful energy policy, we must incorporate some additional
149 “The Hubbert Peak for World Oil.” 12 Feb. 2001. EcoSystems. 19 Mar. 2003.
132 funding to account for the increase in energy demand each year. Figure 5.0.4 below was
generated from data provided by Energy Information Administration.
Projected Total Energy Consumption 2000-2025 145 140 135 130 125 120 115 110 105 100
Energy (Quadrillion Btu's) 95
2 4 6 8 0 2 4 6 8 0 1 1 1 1 1 000 00 00 00 2 2 2 2 20 20 20 20 20 20 2020 2022 2024 Year
Figure 5.2.4
As you can see from Figure 5.2.4, the EIA expects an increase of approximately 1.5% each year for the next twenty-five years.151 However, this figure only demonstrates the expected trend that
we should expect to see. The actual energy consumption in future years will deviate, but should
closely follow the slope indicated above. In order to decrease our dependence on petroleum
energy sources, this increase of 1.5% each year must be generated from alternative energy
sources.
When the petroleum supply does run out, the extra money that was put into alternative
energy sources was sufficient enough to replace the amount of energy produced by burning
petroleum and the additional energy consumed each year. This allows the United States and
many other countries to put the minimal amount of money into the research and development of
151 “Supplement Tables to the Annual Energy Outlook 2003.” 14 Feb. 2003. Energy Information Administration. 20 Mar. 2003.
133 alternative energy sources all the while finding the country in a prosperous situation when the
world’s petroleum supply runs out. However, if we want the world’s petroleum to supply to last
as long as possible, more than just the minimal amount of effort must be put into this
transformation.
The use of coal has been speculated to be a reasonable replacement for oil. Along with
oil, coal has been one of the leading energy sources in the country providing the United States
with cheap energy for many years. In 2002, coal energy sources produced enough electricity to
account for approximately 23% of energy needs in the United States.152 One major difference
between oil and coal energy sources is that the coal supply is so abundant that it is projected to
last for the next 250 years.153 However, the use of coal will only delay the energy crisis until a
later date.
In the early 1900’s, coal was the primary energy source providing the United States with
80% of their total energy needs.154 Since then, coal consumption has dropped off to about 23% in the late 1900’s reaching a coal consumption of approximately 1,063 million short tons (Mmst) by 2002.155 The amount of remaining coal does not appear to be an issue as it consists of 95% of
today’s fossil fuel reserves. Not only is the coal supply expected to last for centuries to come,
but the Nation Coal Council projects that coal will have a significant price advantage over all
152 “United States Country Analysis Brief.” Energy Information Administration. 13 Nov. 2002.
134 other energy production methods.156 At this point in time, the world is aware of the depleting oil
supply and the need for an alternative energy source. Since the coal supply is abundant and their
prices are competitive with many of today’s primary energy sources, it seems conceivable that
coal would be an excellent replacement for the depleting oil.
One major problem with coal is that it is a finite resource. All finite resources portray the
same pattern of production. Production starts off slow in the beginning, reaching a peak point,
and then gradually declines until the supply eventually runs out.157 Regardless of whether or not
our coal supply will last for the next 250 years or so, we will eventually run out of coal. So if we
do implement coal energy sources, then we will run into the same problem many years from now
when we will no longer be able to produce enough coal to meet the energy demand in the future.
If we were to replace all oil energy sources with coal, then coal will produce approximately 65%
of the total energy demand rather than 23% before. Since the total energy consumption has just
about doubled in a short span of ten years, you can expect the coal consumption of 1,063 Mmst
of coal in 2002 to increase to at least 2,100 Mmst by the year 2010.158 At this rate, the coal supply that is suppose to last us for 250 years, will not last nearly that long and we will run into the same energy crisis in the future that we have now.
Another downside of coal is the tremendous amount of pollution emitted by burning coal for electricity generation. In the year 2000, coal emitted enough pollution to account for approximately 37% of the United States’ total carbon emissions, which is only 5% lower than the
156 “Coal in the Future Energy Strategy of the United States.” Jan. 1992. National Coal Council. 16 Apr. 2003.
135 amount of carbon emissions emitted from oil energy sources.159 What makes this statistic amazing is the fact that the amount of coal consumed was almost half the amount of oil that was consumed that year.160 Not only is coal more pollutant than oil, but we would not be decreasing the amount of pollution emitted each year. As a result, health and living conditions would grow significantly worse.
The use of coal energy sources may be a reasonable temporary solution to our upcoming energy crisis, but our economy will suffer substantially in the long run. Due to coal being a finite resource and our total energy consumption increasing each year, our coal supply will run out much sooner than we think leaving us trying to find alternative energy sources to the same situation further down the road. The environmental effects from using coal energy sources are extremely severe and if we were to continually increase our coal consumption, then the negative effects of pollution on the planet will grow worse at a faster rate than we are going right now.
The use of coal as a replacement will not solve our energy crisis but only delay it. In fact, the use of any finite resource as an alternative energy source will not solve our current energy crisis.
The use of renewable, non-polluting energy sources will solve this issue.
5.3 Efficiencies
WIND/SOLAR
Two things must be done in order to make a complete transformation to alternative
energy sources from petroleum energy sources. The first is that all of the additional energy
consumption must be implemented with alternative energy sources. If we keep adding the
additional energy consumption to the petroleum supply, then our petroleum consumption will
159 Ibid. 160 Koopmans, Auke. “Trends in Energy Use.” Regional Wood Energy Development Programme in Asia. 03 Feb. 2003.
136 only decrease due to production issues. The other is to demonstrate a decrease in petroleum
consumption to steer our energy use away from petroleum and prolong our petroleum supply to
essential petroleum uses. Implementing the additional energy needs with alternative energy
sources is only half of the
As shown earlier, the EIA expects the energy consumption to increase approximately
1.5% each year.161 In order to have a successful energy policy, this addition energy must be
implemented with alternative energy sources such as solar and wind power. If there are not
enough alternative energy sources to cover the additional energy consumption, then the extra
consumption will have to implement using different energy sources like petroleum, increasing
our petroleum consumption as a result. Knowing that our petroleum supply is depleting, we
need to decrease our petroleum consumption and conserve the remaining petroleum to the best of
our ability.
In 2003, the EIA estimates a total energy consumption of 99.91 quadrillion Btu’s. This
energy consumption is expected to continually increase to 101.69 quadrillion Btu’s by the end of
the year 2004 corresponding to a total increase of 1.78 quadrillion Btu’s of additional energy.
The projected total energy consumption is expected to continually increase by approximately
1.78 quadrillion Btu’s of energy each year through the year 2025 as demonstrated by the data
provided by the EIA.162 As a result, a constant value of money can be allocated to provide
alternative energy sources for the additional energy needs of the country throughout the twenty-
five year span. Due to the scope of our project, our alternative energy sources will consist of
only solar and wind power. Using the energy generation data and costs from our models in the
161 “Supplement Tables to the Annual Energy Outlook 2003.” 14 Feb. 2003. Energy Information Administration. 20 Mar. 2003.
137 previous section, we can determine a dollar value to allocate towards the implementation of solar
and wind power for the increasing energy demand.
From the data generated in our models, we determined that a 25MW solar power system
costs $125.5 million producing approximately 110,172.7 mega watts each year, whereas a
25MW wind power system costs $25 million producing approximately 30,000 mega watts each
year. As you can clearly see, wind power systems are much cheaper while solar power systems
produce a lot more electricity each year. In the past, the data provided by the EIA indicates that
wind power has been implemented over solar power at a ratio of 91% wind, 9% solar. This ratio
has remained constant for the past ten years or so and due to the cost/power production
associated with each source, we are assuming that this ratio will remain unchanged for future
years to come.163 From this ratio and from the data determined by our solar and wind models,
we determined that it would cost approximately $4.5 billion each year in order to fully transfer
all addition energy needs in the future to alternative energy sources. Now that we achieved an
amount of money to implement additional energy needs with solar and wind power, we must
now allocate money in order to decrease the amount of petroleum consumption each year.
Reducing the amount of petroleum consumption is somewhat more difficult than
compensation the amount of additional energy needs with alternative energy. For some
petroleum uses today, it is easier to replace petroleum with an alternative energy source than
others. For example, it is much more difficult to implement an economically feasible motor
vehicle powered by an alternative energy source than to implement a power plant or heat
buildings with an alternative energy source. Many people want their cars to have good
performance and be cost-effective, two things that alternative energy sources cannot provide at
163 “Electricity Net Generation.” Energy Information Administration. 07 Apr. 2003.
138 this point in time. If a constant amount of money was allocated to decrease our petroleum consumption each year, we should expect to see the petroleum consumption curve decrease in an exponential fashion. In the beginning, some petroleum uses are easy to replace with alternative energy sources explaining the fast decline in the beginning. However, as time goes on, some petroleum uses will require more money and time to replace with alternative energy sources decreasing the rate of decline in future years. An exponential decrease in petroleum consumption allows us to prolong the lifetime of our petroleum supply while keeping the amount of money put into this decrease relatively constant. Since the remaining amount of petroleum on the planet is unknown, it is difficult to accurately determine a decreasing trend that will provide us with a complete transformation to alternative energy sources when the petroleum supply ends.
Ideally, we would like to decrease our petroleum consumption as fast as our petroleum production curve, which will prolong the lifetime of our petroleum supply and give us more control over our petroleum consumption. For environmental reasons, the transformation away from petroleum energy sources ought to occur as soon as possible, but an unreasonable amount of money would be called for if the decreasing trend were too steep. As a result, some care needs to be taken into account to make sure the provided slope does not ask for an impractical amount of money. From the data collected by Dr. C. J. Campbell during a study, we can see that our petroleum production curve forcefully reduces our petroleum consumption by about 45% in the year 2025.164 By the year 2025, we would like our petroleum consumption to be a value much higher than 45% to give us more control over the future of our petroleum consumption without requiring an unreasonable amount of money each year. Reducing our petroleum
164 “The Hubbert Peak for World Oil.” 12 Feb. 2001. EcoSystems. 19 Mar. 2003.
139 consumption by 65% will give us a good distance away from any petroleum production issues while keeping the costs relatively low.
According to the EIA, the total petroleum consumption is expected to be approximately
38.7582 quadrillion Btu’s in 2003.165 Using this value, we were able to determine a percentage decrease from each consecutive year that would reduce our petroleum consumption to about 65% by the year 2025. Decreasing the petroleum consumption each year by 4.1% of the previous year should get us to be around a 65% reduction when the year 2025 is reached. This value may seem quite drastic at first, but from 2025 to 2050, we expect to see only a decrease of 22%. Using this approach, Figure 5.3.1 was developed showing our projected total petroleum consumption up to
2050.
Projected Total Energy Consumption
40 ) 35 30 25 20 15 10 5 Energy (Quadrillion Btu's 0 2000 2004 2008 2012 2016 2020 2024 2028 2032 2036 2040 2044 2048 Year
Figure 5.3.1
Figure 5.3.1 shows the fast decrease in the beginning of the transformation and then how it begins to level off as time goes on. The 65% reduction will give us enough of a buffer period to prolong the lifespan of our petroleum supplies, giving us more time in the future to find alternative ways to create energy. The line in Figure 5.3.1 slowly decreases over time, not
165 “Country Analysis Brief: United States of America.” 13 Nov. 2002. Energy Information Administration. 02 Mar. 2003.
140 because less money is funded, but because the transformation for certain products to use alternative energy sources will become more difficult.
The energy decrease in the first year will determine the amount of funding necessary to achieve the 65% reduction by 2025. During this first year, we expect a decrease of approximately 1.405 quadrillion Btu’s of lost petroleum generated energy. Using the data from our models and the same method as before for the additional energy needs, approximately $3.5 billion to come up with alternative energy sources to compensate for the 1.405 quadrillion Btu loss. Keeping this value constant throughout the twenty-five year span will automatically reduce the petroleum consumption as shown in the figure above.
Now that we have allocated money for both the additional energy needs and reducing the petroleum consumption, we know approximately the total amount of money to be put towards this cause. The total amount of money required to decrease our petroleum consumption by 65% by the year 2025 is approximately $8 billion. The total GDP for the year 2002 was approximately $10.5 trillion.166 The $8 billion needed to achieve this result accounts for only
0.076% of the total GDP for the year of 2002, which is a very small number. The $8 billion dollars will not all go into the implementation of solar and wind power sources, but can be utilized for research and development purposes and subsidies for people to implement their own solar and wind systems.
Since petroleum, gas, and coal are considered the key contributors of energy production in the United States, examining ways of reducing the rate at which we use these valuable commodities should be examined. Since a great deal of machinery uses petroleum and gas such as automobiles and airplanes as well as power plants, the best way to safe guard these valuable
166 “Country Analysis Brief: United States of America.” 13 Nov. 2002. Energy Information Administration. 02 Mar. 2003.
141 commodities would be to reduce the amount of substance used in machines and processes worldwide. In other words, scientific research should be conducted in order to examine any possible way of improving the efficiency of engines and turbines. This would be the first step to help create a buffer for the implementation of a new energy policy. This policy would favor renewable sources of energy more so than the current policy does. The current United States
Energy Policy makes note of the possibility of substantial increases in the volume of renewable sources of energy in the future, but fails to make any type of exact estimates. They make estimates based on more financially affordable renewable energy sources existing in the future.
This estimate assumes that sharp decreases in producing energy via wind, solar, and hydroelectric means will continue in years to follow making these energy sources as cost efficient as the conventional means.
One of the greatest problems in changing the energy policy today is the inability of policy makers to take into account the environmental effects as well as the economic effects of failing to use renewable energy sources more abundantly. Policy makers typically look at the hard facts. Will installing a wind farm that is capable of producing just as much power as a gas powered plant cost less or more over time? Questions like this relate to the constant evil that energy policy makers are faced with, money. Money is by far the most powerful means of pushing forth policy. Whoever has it can lobby in congress to push forth their points of view.
Of course, the government has tried to implement new laws and policies to reduce the usage of non-renewable energy sources, but change comes slowly and painfully. Unfortunately for the environment and the consumer, companies that produce energy by the current means are making a great deal of money. These companies are the ones that are in the best position to develop and implement renewable forms of energy. Since the costs of producing these forms of energy
142 would reduce the total amount of income that they receive, in most cases, they prefer to stick with their current means of production. Of course, all of these facts are mere philosophies centered around the human way of thinking. Putting it as plainly as possible, renewable energy is too expensive at the present time for most investors to seriously consider it as a source of energy. They are much less concerned with the fact that it’s a cleaner form of energy and that they are helping to reduce the usage of other forms of energy by contributing their energy to the grid.
Currently, research and development being constructed by private investors and governments worldwide are focusing their efforts on increasing the efficiency of energy produced via solar and wind power. These efficiencies are discussed in detail earlier in this paper. The fact remains that until these levels come to a point where using renewable forms of energy is more cost effective than not, policy will most likely remain the same as what it is today. Again, the government is not completely blind to the issue of efficiencies. The United
States Federal Government is helping to increase the likelihood that private companies will be willing to invest in renewable energy sources by helping to lower these efficiencies. Besides aiding in technological advances in renewable energy production, the government has done other things to help promote investing in the sources. They have consistently given reimbursements and tax cuts to individuals and companies that produce energy via renewable forms. They also have pushed forth other means of preserving energy sources. One way is by rewarding individuals that purchase and use hybrid cars. These cars greatly improve the miles per gallon that cars are able to achieve while driving on the road. With the ever-increasing gas prices and the ever-shortening supply, this is a most effective means of reducing the consumption rates of gasoline that cars use. The government gives tax breaks for individuals who own these types of
143 cars, again, trying to make an effort at their expense to improve the future state of world energy.
Even though the government will directly suffer financially, the environmental benefits over time with an increased usage of this type of car will help to noticeably slow the usage of gasoline and oil. This is just an example of how the government promotes the usage of alternative sources of energy. The car example is, of course, not within the scope of this project.
144 6.0 SOCIAL IMPLICATIONS
6.1 Health Benefits
One of the major points of generating an energy policy is to avoid any negative affects on society as a whole and the individual person. Our current energy methods are extremely damaging to the environment and have a significant effect on living conditions for the human race as well as many species. The relations of many countries could also be affected in future years due to the depleting petroleum supply. These issues were all taken into account when our energy policy was created. The more severe of the two are the health issues correlating to pollution emitted by current petroleum energy sources. As California is one of the leading cities in pollution and has been a focus throughout the IQP, we looked into the effects on Californians due to air pollution.
California emits 3,835,047 lbs of cancer causing pollution each year. This pollution helped cause incidences of 119,900 new cancer cases in 2002. Cancer is a major health concern in the United states being the second leading cause of death in the United States; the first being heart disease. As stated earlier, the pollution that is emitted by a majority of power plants attribute to the cause of many different types of cancer. In particular, lung cancer and illnesses of the respiratory system. According to the American Cancer Society, the rate per 100,000 of the male population for lung and bronchus cancer has increased from 20 in the 1950’s to 80 today.
The major cause of lung and bronchus cancer is tobacco use. However, air pollution is another major contributing factor to the generation of lung and bronchus cancer. Every other form of cancer such as stomach, colon and rectum, prostate, pancreas, liver, and leukemia has remained at a constant rate somewhere between zero and 25 per every 100,000 males for the past century.
145 The major point indicated here is the tremendous increase in lung and bronchus cancer. The data
provided by the American Cancer Society does indicate that this number is declining slightly of
the past couple of years. Ever since the state and government noticed that air pollution was
growing out of control affecting the health of many Americans, they have made an effort to
decrease the amount of pollution emitted by all types of machinery (i.e. power plants, cars).
Also, smoking has decreased drastically over the past couple of years, also assisting in the
decreasing rate. By simply designing products and power plants to emit less pollution will
directly decrease the rate of lung and bronchus cancer found in individuals. A decrease in
pollution will show a direct decrease in the number of cancer incidences will greatly improve the
health of the entire nation.167
According to the National Institutes of Health, the overall costs for cancer in the year
2001 was $156.7 billion. The total cost for all health expenditures to treat cancer was $56.4 billion. Medical bills of this magnitude will surely raise the costs of health insurance. In order for the insurance company to make some kind of return, the insurance fees will have to be raised in order cover the growing costs for illnesses such as cancer. In 1999, at a time when lung and bronchus cancer was at its peak, approximately 16% of Americans under the age of 65 had no health insurance.168 Due to the rising costs of health insurance, many Americans do not have the
finances in order to get help if they find themselves ill or injured. As a result, the overall health
of Americans will be poorer. An attempt must be made to reduce the amount of pollution in the
air in order to increase the level of health in the United States. Solar and wind power will help
achieve this reduction in cancer victims.
167 “Cancer Facts & Figures 2002.” American Cancer Society, Inc. 08 Feb. 2003.
146 The actual number of deaths due to air pollution is appalling. The National Resources
Defense Council estimated that the number of cardiopulmonary deaths per year due to particulate
air pollution ranges somewhere between 3,550 and 7,933 deaths per year in Los Angeles, an
average of 5,873 deaths. The total number of cardiopulmonary deaths among adults in the year
of 1989 was 33,825. Air pollution contributes to approximately 10% to 20% of the total
cardiopulmonary deaths and anywhere between 6% and 13% of the total number of deaths in Los
Angeles in 1989. The National Resources Defense Council mentions that only 1,458 people died
in car accidents in the year of 1989. At least twice as many people died in that year due to air
pollution than in a car accident. These statistics indicate why there is a growing health concern
regarding the pollution in the air. Reducing air pollution by only 25% in the Los Angeles area
could prevent 2,000 deaths per year.169 Death due to air pollution is not a major problem for
rural areas far away from cities, but areas near and around major cities have relatively high
mortality rates due to air pollution.
Air pollution has a larger impact on the overall health of society than imaginable.
Approximately 10% of the people who die in a year die due to air pollution. The cancer causing
side affects due to air pollution also have a great impact on the overall health of the people in the
United States. To implement fossil fuel power plants will only make the problem grow worse,
whereas the implementation of solar and wind power will help eliminate air pollution from being
a cause to any major health issues, greatly benefiting the overall health of the economy and the
American. To push along this great benefit from solar and wind power, the state and government must offer subsidies and rebates to increase the demand and value for purchasing these clean systems, which can be included in the $8 billion/year as long as at least $8 is spent.
169 “California: Particulate Air Pollution Attributable Mortality by MSA.” National Resources Defense Council. 20 Feb. 2003.
147 Public health is a major concern, but the implications of what the decreasing oil supply may bring to the relationship between countries should not be overlooked. We currently see today that our petroleum prices are constantly rising making us realize each time we put gas in our cars that we need to find alternative ways to create energy. These prices will only continue to rise as the world’s petroleum supply diminishes. As these prices rise and there is not enough petroleum to go around, conflicts between countries may arise. Currently, the current war with
Iraq has been considered by some to be a war for Iraq’s petroleum and not for weapon’s of mass destruction and freedom for the Iraqi people. The Bush administration has made it clear that the war is definitely not over Iraq’s petroleum. However, if some people believe that the Bush administration is lying when there is no shortage of petroleum at the moment, then imagine how severe these accusations can be in the future when there is a shortage. By reducing our petroleum demand far below the supply, we are safeguarding ourselves from problems like this in the future preventing possible war in the future.
Petroleum is an all around poor energy source. Petroleum is limited in supply and there are many different negative affects associated with it. Cancer and disease is increased due to the toxins released by petroleum when it is burned, which creates poorer living conditions for all species. World peace may also be compromised as a result of a decreasing petroleum supply.
By following our energy policy and convert to alternative energy sources, we succeed in improving the health of the community as well as keep world peace. Staying with petroleum energy sources will only lead to problems in the future whereas alternative energy sources will only lead to positive results helping with the advancement of the human race.
148
6.2 Societal Consequences of Inaction
One of the most important aspects of addressing the energy crisis are the problems that will arise if action is not taken. The most evident consequences will be a complete loss of generated energy to the public as a whole. In the United States as it is, Californian residents and companies have already had to endure rolling blackouts in response to a lack of energy during the summer months. Although many countries throughout the world do not supply power to all their citizens, even first world countries such as the United States, Canada, European countries, and China will all experience power outages if alternative energy sources are not sought out and implemented. Despite losing power, the other major result of inaction will be, as aforementioned, pollution that could cause health issues for people as well as environmental issues for plants and animals.
In the event that additional power is not found when fossil fuel reserves start to run out, the results would be vast and terrible. Of course, all the results cannot be examined fully in this section. We will bring to light the most important impacts of blackouts of electricity in this section. One of the most important aspects of society is the business sector. In recent times, companies have become more and more dependant on energy to fuel their businesses. The most important part of many companies is their information technology department. IT departments help to manage accounting, marketing, human resources, and other core functions associated with running a company. Without power to run the information technology sectors, companies would be crippled. Since companies are what drive the economy along with consumers, the economy would take an incredible hit. With the economy taking a hit, the consequences to society as a whole would be impossible to forecast. The economy is a direct function of
149 society’s ability to thrive. This is especially true in a capitalistic economy where the ability of
the common man to thrive and obtain wealth is dependant on the freedoms associated with living
in the society. If the common man is unable to operate as he wants, the business function of the
company would be crippled. Food supplies would fall to ruin since the money to grow and
harvest crops would be lost. The transportation sector would be hit incredibly hard. There is no
way as of right now to substitute the energy sources of our current jet plants, cars, and trucks
without some type of reliance on fossil fuel energy sources. When transportation goes down,
there will be no way to carry around the essential items that need to be imported and exported for
human survival. The issues associated with the loss of power are innumerable since there are so
many different areas of life that are reliant upon energy.
There are also the concerns associated with the continuation of the pouring of pollutants
into both the air and water of the world. The immediate effects are devastating. In addition to
the cardiopulmonary problems discussed earlier in this section, there are other health issues that
are caused by pollution that in some cases leads to death of the individual. The World Health
Association has made estimates regarding the effects of air pollution on human life. They
estimate that “200,000 to 570,000 [deaths occur], representing about 0.4 to 1.1 percent of total
annual deaths.”170 Numbers like this are frightening when they are put into numbers. There is
way that there should be any percentage of death occurring from pollution. Since our society in
general is so reliant upon energy, however, and since the most economically feasible way to
produce it is via fossil fuels, there really isn’t any way to avoid polluting the environment at the
current time. Of course, as discussed, emissions can be reduced through the substation of energy
production via alternative means such as wind and solar energy. It’s important that these two
170 “Health Effects of Air Pollution.” World Resources Institute. 20 April 2003. < http://www.wri.org/wri/wr-98- 99/airpoll.htm>
150 sources are the primary forms of alternative energy used. Even renewable sources such as
biomass create a large degree in the pollution of the environment despite its supposedly
“renewable” categorization. The following image illustrates that biomass use is still relatively
high despite the fact that it’s one of the leading causes of indoor air pollution worldwide. Indoor air pollution being the air that is contained within factories, businesses, stores, etc. Exposure to the fumes from burning biomass has been attributed to “at least four major categories of illness: acute respiratory infections (ARI) in children; chronic obstructive lung diseases such as asthma and chronic bronchitis; lung cancer; and stillbirths and other problems at birth”171
Figure 6.2.1
It can only be hoped that in future years, through alteration of the energy policy as well as reform in the attitudes that people exhibit, that production of pollutants can be reduced. It’s incredibly important to understand that current thought processes in regards to energy are centered on
171 Ibid.
151 economic efficiency and feasibility. When society realizes as a whole that this will not work in the future, and that concessions must be made, our energy problems will slowly recede.
152 7.0 CONCLUSION
This IQP deals with the eminent energy crisis in the United States. Our current energy generation methods are not only limited in supply, but they’re also damaging to the environment and are associated with many of the most prevalent health issues experienced today. Solar and wind powered systems are purely renewable energy sources meaning that their availability is almost unlimited in scope. Energy is produced straight from wind and sunlight, meaning nothing is burnt or processed in the way fossil fuels are. This assures that no pollution of any kind is emitted. These systems also have very low maintenance costs and are extremely versatile. They can produce energy anywhere as long as wind or sunlight is present. Our IQP developed an energy policy based on solar and wind-powered systems that not only improves the environment and health conditions of society within the next thirty years, but also prolongs the lifetime of our petroleum supply.
Petroleum energy sources emit very large quantities of pollution having major impacts on the environment. Pollution is commonly known to raise the average global temperature and creating smog (a thick haze) over major cities. However, pollution has numerous effects that the common person does not know about. Acid rain forms when certain toxins combine in the atmosphere, the climate is altered globally, ocean levels rise, and many of the toxins contained in the pollution are introduced into our water and food reducing the overall quality of life creating unwanted diseases. Due to the harmful impacts from the pollution of petroleum energy sources, our energy policy strives to reduce the overall amount of pollution emitted before an irreversible amount of damage is done to the planet.
Solar and wind power have been around for over a hundred years, but it was not until the mid 1950's that solar and wind power systems were beginning to be implemented in any small-
153 scale and large-scale applications. In the beginning, these systems were extremely expensive
and inefficient making the application of solar and wind power impractical. Over the last twenty years, many new and important discoveries were made that have significantly brought down the prices and raised the efficiencies of solar and wind power systems. Even though the environmental benefits, and high reliability of these systems far outweigh the price in the long run, the initial costs to implement solar and wind power systems are unappealing. However, once the initial investment is paid off, both systems prove to be profitable due to their low maintenance costs and high reliability. A solar power system sees a return on investment in around thirteen years whereas a wind power system sees a return on investment in seven years.
The cost and production for these systems depends entirely on the size and location. There is one important fact that remains constant. Wind power systems are cheaper and they see a return on investment at a much earlier date than solar power systems making wind power systems more practical to implement than solar power. The costs for these systems have not reached market level yet, but it is much cheaper to apply solar and wind power to secluded parts of the world like
oilrigs, isolated villages, and the orbit of earth (solar only) rather than spending a larger sum of
money to connect to the nearest utility grid. As time goes on, solar and wind power systems will
become more appealing as scientists and engineers around the world work continuously to
further understand the concepts of these systems and make new discoveries that have and will
further enhance the efficiencies and reduce the making these systems a more economical energy
source.
The main portion of this IQP was to generate an energy policy that would not only
provide the United States with a policy that will transfer all petroleum energy sources to solar
and wind power systems, but to prolong the lifetime of our petroleum supply as well. We feel
154 that the United States’ current energy policy does not do enough to alleviate the use of our petroleum supply. If changes aren’t made to our current energy policy, then the United States will almost inevitably find itself in a terrible energy crisis in the future. Our petroleum supply is constantly depleting and there is no exact way to predict when and how fast the petroleum supply will be exhausted. Estimations can only be made using remaining amount of oil known to exist.
There are still unknown amounts of oil deposits remaining forcing us to take a conservative approach to the issue or else we will not have enough alternative energy sources to compensate for the lost petroleum energy sources. From our research, we determined that allocating $8 billion each year towards alternative energy sources, we should expect to see approximately a
65% reduction in our petroleum consumption by the year 2025. By increasing the energy efficiencies of products will decrease our energy consumption assisting with the reduction in our petroleum consumption. This approach is somewhat aggressive, but due to the possible consequences of a fast decreasing petroleum supply, aggressive action needs to be taken in order to avoid disaster. Successfully making this transformation to alternative energy sources reduces the amount of pollution resulting in less disease, healthier living conditions, and a more natural climate. From a financial standpoint, the United States will avoid the expenditure of billions and billions of dollars on oil due to rising prices in the future and possible conflicts with other countries regarding the remaining petroleum.
Our report brings to light one of the most prevalent issues to human society today. It can only be hoped that the most apt scientists and engineers work diligently in the near future to help combat this issue. Of course, our report does not examine the other types of renewable energy sources that exist today. We felt as though the two energy sources examined, wind and solar, were the two most promising technologies to examine. Other renewable sources would be just as
155 useful in helping to combat the energy crisis. We can only hope that humanity as a whole addresses the issues brought forth in this paper. Time is our adversary at this point. If action is taken in the near future, we can easily avert a worldwide energy crisis. Only time will tell, however, if humanity will actually be able to handle this tough test.
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