DOCSLIB.ORG

Electrical Power Conversion of a River and Tidal Power Generator

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Electrical Power Conversion of a River and Tidal Power Generator Electrical Power Conversion of a River and Tidal Power Generator Preprint Eduard Muljadi, Vahan Gevorgian, and Alan Wright National Renewable Energy Laboratory James Donegan, Cian Marnagh, and Jarlath McEntee Ocean Renewable Power Company To be presented at the 2016 IEEE North American Power Symposium Denver, Colorado September 18–20, 2016 © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency & Renewable Energy Operated by the Alliance for Sustainable Energy, LLC This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. Conference Paper NREL/CP-5D00-66866 September 2016 Contract No. DE-AC36-08GO28308 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (Alliance), a contractor of the US Government under Contract No. DE-AC36-08GO28308. Accordingly, the US Government and Alliance retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof. This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. Available electronically at SciTech Connect http:/www.osti.gov/scitech Available for a processing fee to U.S. Department of Energy and its contractors, in paper, from: U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 OSTI http://www.osti.gov Phone: 865.576.8401 Fax: 865.576.5728 Email: [email protected] Available for sale to the public, in paper, from: U.S. Department of Commerce National Technical Information Service 5301 Shawnee Road Alexandria, VA 22312 NTIS http://www.ntis.gov Phone: 800.553.6847 or 703.605.6000 Fax: 703.605.6900 Email: [email protected] Cover Photos by Dennis Schroeder: (left to right) NREL 26173, NREL 18302, NREL 19758, NREL 29642, NREL 19795. NREL prints on paper that contains recycled content. Electrical Power Conversion of a River and Tidal Power Generator E. Muljadi, V. Gevorgian, A. Wright, J. Donegan, C. Marnagh, J. McEntee Abstract—As renewable generation has become less expensive energy investments in the power sector outpacing net during recent decades, and it becomes more accepted by the investments in fossil-fueled power plants. The most rapid global population, the focus on renewable generation has growth and the largest increase in renewable capacity occurred expanded to include new types with promising future in the power sector and was dominated by three technologies: applications, such as river and tidal generation. Although the utilization of power electronics and electric wind, solar photovoltaic (PV), and hydropower. machines in industry is phenomenal, the emphasis on system This paper describes the electrical power conversion design is different for various sectors of industry. In precision aspects of river and tidal generation. Although modern power control, robotics, and weaponry, the design emphasis is on converter control is available to control the generation side, accuracy and reliability with less concern for the cost of the final we choose the design on the basis of minimizing the capital product. In energy generation, the cost of energy is the prime expenditures and operations and maintenance expenditures; concern; thus, capital expenditures (CAPEX) and operations and maintenance expenditures (OPEX) are the major design thus, the architecture is relatively simple and modular for ease objectives. of replacement and maintenance. The power conversion is This paper describes the electrical power conversion aspects simplified by considering a simple diode bridge and a DC-DC of river and tidal generation. Although modern power converter power converter to take advantage of abundant and low-cost control is available to control the generation side, the design was PV inverters that have well-proven grid integration chosen on the bases of minimizing the CAPEX and OPEX; thus, characteristics (i.e., the capability to produce energy with good the architecture is simple and modular for ease of replacement power quality and control real power and voltage at the grid and maintenance. The power conversion is simplified by considering a simple diode bridge and a DC-DC power converter side). to take advantage of abundant and low-cost photovoltaic inverters that have well-proven grid integration characteristics (i.e., the capability to produce energy with good power quality and control real power and voltage on the grid side). Index Terms—ocean power, marine, hydrokinetic, tidal, river, renewable, water power, variable generation, distributed generation. I. INTRODUCTION HIS work is based on a hydrokinetic power generating T system for river and tidal generators. The analysis is based on a tentative tidal generator with the power rating of 40 kW, although the same generator can be operated as a river Fig. 1. Typical bottom-mounted tidal generator (source Wikipedia) generator. From the resource perspective, tidal generation is dependent on the resource availability; thus, the resource must A typical tidal generator can be mounted on the bottom of be identified by preliminary assessment and survey [1]. One an estuary, and its shape and structure are similar to that of the difference between a tidal generator and a river generator is wind turbine generator as shown in the Figure 1. The Savonius the water flow driving each turbine. In river generation, the turbine type is also used as the river and tidal generators. It water flows in one direction and is more or less constant. In may be placed vertically or horizontally depending on the tidal generation, the water flows in two directions: during the characteristics of the resource and the site. flood, the water flows from the ocean toward the land or river; This paper is arranged as follows. Section II discusses the during the ebb, the water flows back toward the ocean. There electrical power conversion. The permanent magnet generator are various ways to harness tidal generation, either from a is presented in Section III, followed by the power converters single turbine [2–3], a combination of wind generators and in Section IV. Finally, Section V presents the conclusion and tidal generators [4], or in a multiple-turbine or tidal power summary. plant environment [5]. Each site has its own characteristics; thus, control and optimization may be unique for different II. SYSTEM-LEVEL DESCRIPTION installations [6–8]. The electrical power conversion in tidal generation is very In 2014, renewable energy expanded significantly in terms similar to the generating system of wind power generation. It of capacity installed and energy produced, with renewable consists of major components: a rectifier (variable AC to DC 1 This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. converter) and an inverter (DC to AC 60-Hz converter). III. PERMANENT MAGNET SYNCHRONOUS GENERATOR Depending on the generator type, the rectifier can be a passive The PMSG is very popular in variable generation rectifier [9] or an active rectifier [10]. For this discussion, we applications. Many of these applications are based on direct- assume that the system described in this paper is based on a drive generators that use rare-earth permanent magnets (PM). passive rectifier. Thus, a DC-DC converter is used to match The advantage of rare-earth PMs is that the residual flux and maintain the DC bus voltage constant. With an active density is very high, commonly B = 1.4 Tesla or higher. In rectifier, it is possible to control the DC bus voltage by comparison, the commonly used PM in the past has been the utilizing the active rectifier alone. This section presents the ferrite magnet, which has a low flux density, B = 0.4 Tesla or electrical power conversion. The maximum power point lower. tracker (MPPT) is similar to the one used in wind power A high flux density magnet is very important because, for generation, however, the implementation is determined by the the same power rating and rotational speeds, the higher the shape of the performance coefficient (Cp) characteristic (Cp flux density, the smaller and lighter the generator will be. It is versus tip-speed-ratio). Detail discussion can be found in [11]. assumed that the PM generator used is surface mounted. The A river and tidal generator using a permanent magnet equivalent circuit of a PM generator is shown in Figure 4. synchronous generator (PMSG) is investigated. A PMSG has the advantage of higher efficiency and reliability. Because of A. PMSG Connected to a Constant DC Bus via a Rectifier its lack of a field winding and the nature of variable In this section, the PMSG is connected to a constant DC generation, the PMSG is typically controlled by a series of bus voltage via a three-phase rectifier.
Load more

Recommended publications
  • "New Energy Economy": an Exercise in Magical Thinking
    REPORT | March 2019 THE “NEW ENERGY ECONOMY”: AN EXERCISE IN MAGICAL THINKING Mark P. Mills Senior Fellow The “New Energy Economy”: An Exercise in Magical Thinking About the Author Mark P. Mills is a senior fellow at the Manhattan Institute and a faculty fellow at Northwestern University’s McCormick School of Engineering and Applied Science, where he co-directs an Institute on Manufacturing Science and Innovation. He is also a strategic partner with Cottonwood Venture Partners (an energy-tech venture fund). Previously, Mills cofounded Digital Power Capital, a boutique venture fund, and was chairman and CTO of ICx Technologies, helping take it public in 2007. Mills is a regular contributor to Forbes.com and is author of Work in the Age of Robots (2018). He is also coauthor of The Bottomless Well: The Twilight of Fuel, the Virtue of Waste, and Why We Will Never Run Out of Energy (2005). His articles have been published in the Wall Street Journal, USA Today, and Real Clear. Mills has appeared as a guest on CNN, Fox, NBC, PBS, and The Daily Show with Jon Stewart. In 2016, Mills was named “Energy Writer of the Year” by the American Energy Society. Earlier, Mills was a technology advisor for Bank of America Securities and coauthor of the Huber-Mills Digital Power Report, a tech investment newsletter. He has testified before Congress and briefed numerous state public-service commissions and legislators. Mills served in the White House Science Office under President Reagan and subsequently provided science and technology policy counsel to numerous private-sector firms, the Department of Energy, and U.S.
    [Show full text]
  • Innovation Outlook: Ocean Energy Technologies, International Renewable Energy Agency, Abu Dhabi
    INNOVATION OUTLOOK OCEAN ENERGY TECHNOLOGIES A contribution to the Small Island Developing States Lighthouses Initiative 2.0 Copyright © IRENA 2020 Unless otherwise stated, material in this publication may be freely used, shared, copied, reproduced, printed and/or stored, provided that appropriate acknowledgement is given of IRENA as the source and copyright holder. Material in this publication that is attributed to third parties may be subject to separate terms of use and restrictions, and appropriate permissions from these third parties may need to be secured before any use of such material. ISBN 978-92-9260-287-1 For further information or to provide feedback, please contact IRENA at: [email protected] This report is available for download from: www.irena.org/Publications Citation: IRENA (2020), Innovation outlook: Ocean energy technologies, International Renewable Energy Agency, Abu Dhabi. About IRENA The International Renewable Energy Agency (IRENA) serves as the principal platform for international co-operation, a centre of excellence, a repository of policy, technology, resource and financial knowledge, and a driver of action on the ground to advance the transformation of the global energy system. An intergovernmental organisation established in 2011, IRENA promotes the widespread adoption and sustainable use of all forms of renewable energy, including bioenergy, geothermal, hydropower, ocean, solar and wind energy, in the pursuit of sustainable development, energy access, energy security and low-carbon economic growth and prosperity. Acknowledgements IRENA appreciates the technical review provided by: Jan Steinkohl (EC), Davide Magagna (EU JRC), Jonathan Colby (IECRE), David Hanlon, Antoinette Price (International Electrotechnical Commission), Peter Scheijgrond (MET- support BV), Rémi Gruet, Donagh Cagney, Rémi Collombet (Ocean Energy Europe), Marlène Moutel (Sabella) and Paul Komor.
    [Show full text]
  • Lecture 10: Tidal Power
    Lecture 10: Tidal Power Chris Garrett 1 Introduction The maintenance and extension of our current standard of living will require the utilization of new energy sources. The current demand for oil cannot be sustained forever, and as scientists we should always try to keep such needs in mind. Oceanographers may be able to help meet society's demand for natural resources in some way. Some suggestions include the oceans in a supportive manner. It may be possible, for example, to use tidal currents to cool nuclear plants, and a detailed knowledge of deep ocean flow structure could allow for the safe dispersion of nuclear waste. But we could also look to the ocean as a renewable energy resource. A significant amount of oceanic energy is transported to the coasts by surface waves, but about 100 km of coastline would need to be developed to produce 1000 MW, the average output of a large coal-fired or nuclear power plant. Strong offshore winds could also be used, and wind turbines have had some limited success in this area. Another option is to take advantage of the tides. Winds and solar radiation provide the dominant energy inputs to the ocean, but the tides also provide a moderately strong and coherent forcing that we may be able to effectively exploit in some way. In this section, we first consider some of the ways to extract potential energy from the tides, using barrages across estuaries or tidal locks in shoreline basins. We then provide a more detailed analysis of tidal fences, where turbines are placed in a channel with strong tidal currents, and we consider whether such a system could be a reasonable power source.
    [Show full text]
  • Energy Budget of the Biosphere and Civilization: Rethinking Environmental Security of Global Renewable and Non-Renewable Resources
    ecological complexity 5 (2008) 281–288 available at www.sciencedirect.com journal homepage: http://www.elsevier.com/locate/ecocom Viewpoint Energy budget of the biosphere and civilization: Rethinking environmental security of global renewable and non-renewable resources Anastassia M. Makarieva a,b,*, Victor G. Gorshkov a,b, Bai-Lian Li b,c a Theoretical Physics Division, Petersburg Nuclear Physics Institute, Russian Academy of Sciences, 188300 Gatchina, St. Petersburg, Russia b CAU-UCR International Center for Ecology and Sustainability, University of California, Riverside, CA 92521, USA c Ecological Complexity and Modeling Laboratory, Department of Botany and Plant Sciences, University of California, Riverside, CA 92521-0124, USA article info abstract Article history: How much and what kind of energy should the civilization consume, if one aims at Received 28 January 2008 preserving global stability of the environment and climate? Here we quantify and compare Received in revised form the major types of energy fluxes in the biosphere and civilization. 30 April 2008 It is shown that the environmental impact of the civilization consists, in terms of energy, Accepted 13 May 2008 of two major components: the power of direct energy consumption (around 15 Â 1012 W, Published on line 3 August 2008 mostly fossil fuel burning) and the primary productivity power of global ecosystems that are disturbed by anthropogenic activities. This second, conventionally unaccounted, power Keywords: component exceeds the first one by at least several times. Solar power It is commonly assumed that the environmental stability can be preserved if one Hydropower manages to switch to ‘‘clean’’, pollution-free energy resources, with no change in, or Wind power even increasing, the total energy consumption rate of the civilization.
    [Show full text]
  • Considering Biodiversity for Solar and Wind Energy Investments Introduction
    IBAT briefing note Considering Biodiversity for Solar and Wind Energy Investments Introduction The Integrated Biodiversity Assessment Tool provides a such as mortality of birds and bats at wind farms and indirect mechanism for early-stage biodiversity risk screening of impacts, such as the development of new roads which lead to commercial operations. The rapid shift in energy investments other pressures on the ecosystem. Fortunately, many impacts from fossil fuels to renewable energy requires banks and to the most vulnerable species can be avoided as sensitivity investors to take new considerations into account to avoid mapping has repeatedly shown that there is ample space unintended negative environmental impacts from their to safely deploy renewable energies at the scale needed investments. The International Union on the Conservation to meet national targets¹ and avoid globally important places of Nature (IUCN) - an IBAT Alliance member - has recently for biodiversity.² produced new guidelines on ‘Mitigating Biodiversity Impacts Adequate diligence will be required to ensure that responsible Associated with Solar and Wind Energy Development’. investing is applied to renewable energy financing. Instruments, This briefing note complements the IUCN/TBC Guidelines such as green bonds³ and sustainability-linked loans,4 equity and supports IBAT users to understand the potential investment into thematic funds, or sovereign bonds will biodiversity impacts from this fast-growing area of finance. continue to play a major role in helping to finance this sector. Large areas of land and oceans are needed to site renewable With the increasing appetite for investment in environmentally energy infrastructure to meet rising energy demands in areas sustainable projects, there is a danger that biodiversity impacts of economically viable wind and solar resource.
    [Show full text]
  • Wind Energy Glossary: Technical Terms and Concepts Erik Edward Nordman Grand Valley State University, [email protected]
    Grand Valley State University ScholarWorks@GVSU Technical Reports Biology Department 6-1-2010 Wind Energy Glossary: Technical Terms and Concepts Erik Edward Nordman Grand Valley State University, [email protected] Follow this and additional works at: http://scholarworks.gvsu.edu/bioreports Part of the Environmental Indicators and Impact Assessment Commons, and the Oil, Gas, and Energy Commons Recommended Citation Nordman, Erik Edward, "Wind Energy Glossary: Technical Terms and Concepts" (2010). Technical Reports. Paper 5. http://scholarworks.gvsu.edu/bioreports/5 This Article is brought to you for free and open access by the Biology Department at ScholarWorks@GVSU. It has been accepted for inclusion in Technical Reports by an authorized administrator of ScholarWorks@GVSU. For more information, please contact [email protected]. The terms in this glossary are organized into three sections: (1) Electricity Transmission Network; (2) Wind Turbine Components; and (3) Wind Energy Challenges, Issues and Solutions. Electricity Transmission Network Alternating Current An electrical current that reverses direction at regular intervals or cycles. In the United States, the (AC) standard is 120 reversals or 60 cycles per second. Electrical grids in most of the world use AC power because the voltage can be controlled with relative ease, allowing electricity to be transmitted long distances at high voltage and then reduced for use in homes. Direct Current A type of electrical current that flows only in one direction through a circuit, usually at relatively (DC) low voltage and high current. To be used for typical 120 or 220 volt household appliances, DC must be converted to AC, its opposite. Most batteries, solar cells and turbines initially produce direct current which is transformed to AC for transmission and use in homes and businesses.
    [Show full text]
  • The Deep, Hot Biosphere (Geochemistry/Planetology) THOMAS GOLD Cornell University, Ithaca, NY 14853 Contributed by Thomas Gold, March 13, 1992
    Proc. Natl. Acad. Sci. USA Vol. 89, pp. 6045-6049, July 1992 Microbiology The deep, hot biosphere (geochemistry/planetology) THOMAS GOLD Cornell University, Ithaca, NY 14853 Contributed by Thomas Gold, March 13, 1992 ABSTRACT There are strong indications that microbial gasification. As liquids, gases, and solids make new contacts, life is widespread at depth in the crust ofthe Earth, just as such chemical processes can take place that represent, in general, life has been identified in numerous ocean vents. This life is not an approach to a lower chemical energy condition. Some of dependent on solar energy and photosynthesis for its primary the energy so liberated will increase the heating of the energy supply, and it is essentially independent of the surface locality, and this in turn will liberate more fluids there and so circumstances. Its energy supply comes from chemical sources, accelerate the processes that release more heat. Hot regions due to fluids that migrate upward from deeper levels in the will become hotter, and chemical activity will be further Earth. In mass and volume it may be comparable with all stimulated there. This may contribute to, or account for, the surface life. Such microbial life may account for the presence active and hot regions in the Earth's crust that are so sharply of biological molecules in all carbonaceous materials in the defined. outer crust, and the inference that these materials must have Where such liquids or gases stream up to higher levels into derived from biological deposits accumulated at the surface is different chemical surroundings, they will continue to repre- therefore not necessarily valid.
    [Show full text]
  • Hydroelectric Power -- What Is It? It=S a Form of Energy … a Renewable Resource
    INTRODUCTION Hydroelectric Power -- what is it? It=s a form of energy … a renewable resource. Hydropower provides about 96 percent of the renewable energy in the United States. Other renewable resources include geothermal, wave power, tidal power, wind power, and solar power. Hydroelectric powerplants do not use up resources to create electricity nor do they pollute the air, land, or water, as other powerplants may. Hydroelectric power has played an important part in the development of this Nation's electric power industry. Both small and large hydroelectric power developments were instrumental in the early expansion of the electric power industry. Hydroelectric power comes from flowing water … winter and spring runoff from mountain streams and clear lakes. Water, when it is falling by the force of gravity, can be used to turn turbines and generators that produce electricity. Hydroelectric power is important to our Nation. Growing populations and modern technologies require vast amounts of electricity for creating, building, and expanding. In the 1920's, hydroelectric plants supplied as much as 40 percent of the electric energy produced. Although the amount of energy produced by this means has steadily increased, the amount produced by other types of powerplants has increased at a faster rate and hydroelectric power presently supplies about 10 percent of the electrical generating capacity of the United States. Hydropower is an essential contributor in the national power grid because of its ability to respond quickly to rapidly varying loads or system disturbances, which base load plants with steam systems powered by combustion or nuclear processes cannot accommodate. Reclamation=s 58 powerplants throughout the Western United States produce an average of 42 billion kWh (kilowatt-hours) per year, enough to meet the residential needs of more than 14 million people.
    [Show full text]
  • Hydropower Technologies Program — Harnessing America’S Abundant Natural Resources for Clean Power Generation
    U.S. Department of Energy — Energy Efficiency and Renewable Energy Wind & Hydropower Technologies Program — Harnessing America’s abundant natural resources for clean power generation. Contents Hydropower Today ......................................... 1 Enhancing Generation and Environmental Performance ......... 6 Large Turbine Field-Testing ............................... 9 Providing Safe Passage for Fish ........................... 9 Improving Mitigation Practices .......................... 11 From the Laboratories to the Hydropower Communities ..... 12 Hydropower Tomorrow .................................... 14 Developing the Next Generation of Hydropower ............ 15 Integrating Wind and Hydropower Technologies ............ 16 Optimizing Project Operations ........................... 17 The Federal Wind and Hydropower Technologies Program ..... 19 Mission and Goals ...................................... 20 2003 Hydropower Research Highlights Alden Research Center completes prototype turbine tests at their facility in Holden, MA . 9 Laboratories form partnerships to develop and test new sensor arrays and computer models . 10 DOE hosts Workshop on Turbulence at Hydroelectric Power Plants in Atlanta . 11 New retrofit aeration system designed to increase the dissolved oxygen content of water discharged from the turbines of the Osage Project in Missouri . 11 Low head/low power resource assessments completed for conventional turbines, unconventional systems, and micro hydropower . 15 Wind and hydropower integration activities in 2003 aim to identify potential sites and partners . 17 Cover photo: To harness undeveloped hydropower resources without using a dam as part of the system that produces electricity, researchers are developing technologies that extract energy from free flowing water sources like this stream in West Virginia. ii HYDROPOWER TODAY Water power — it can cut deep canyons, chisel majestic mountains, quench parched lands, and transport tons — and it can generate enough electricity to light up millions of homes and businesses around the world.
    [Show full text]
  • Oceans Powering the Energy Transition: Progress Through Innovative Business Models and Revenue Supports
    WEBINAR SERIES Oceans powering the energy transition: Progress through innovative business models and revenue supportS Judit Hecke & Alessandra Salgado Rémi Gruet Innovation team, IRENA CEO, Ocean Energy Europe TUESDAY, 12 MAY 2020 • 10:00AM – 10:30AM CET WEBINAR SERIES TechTips • Share it with others or listen to it again ➢ Webinars are recorded and will be available together with the presentation slides on #IRENAinsights website https://irena.org/renewables/Knowledge- Gateway/webinars/2020/Jan/IRENA-insights WEBINAR SERIES TechTips • Ask the Question ➢ Select “Question” feature on the webinar panel and type in your question • Technical difficulties ➢ Contact the GoToWebinar Help Desk: 888.259.3826 or select your country at https://support.goto.com/webinar Ocean Energy Marine Energy Tidal Energy Wave Energy Floating PV Offshore Wind Ocean Energy Ocean Thermal Energy Salinity Gradient Conversion (OTEC) 4 Current Deployment and Outlook Current Deployment (MW): Ocean Energy Forecast (GW) IRENA REmap forecast 10 GW of installed capacity by 2030 Total: 535.1 MW Total: 13.55 MW Ocean Energy Pipeline Capacity (MW) 5 IRENA Analysis for Upcoming Report Mapping deployed and planned projects, visualizing by technology, country, capacity, etc. Examples: Announced wave energy capacity and projects by device type Announced ocean energy additions by technology in 2020 Countries in ocean energy market (deployed and / or pipeline projects) Filed tidal energy patents by country 6 Innovative Business Models Coupling with other Renewable Energy Sources
    [Show full text]
  • Concentrating Solar Power: Energy from Mirrors
    DOE/GO-102001-1147 FS 128 March 2001 Concentrating Solar Power: Energy from Mirrors Mirror mirror on the wall, what's the The southwestern United States is focus- greatest energy source of all? The sun. ing on concentrating solar energy because Enough energy from the sun falls on the it's one of the world's best areas for sun- Earth everyday to power our homes and light. The Southwest receives up to twice businesses for almost 30 years. Yet we've the sunlight as other regions in the coun- only just begun to tap its potential. You try. This abundance of solar energy makes may have heard about solar electric power concentrating solar power plants an attrac- to light homes or solar thermal power tive alternative to traditional power plants, used to heat water, but did you know there which burn polluting fossil fuels such as is such a thing as solar thermal-electric oil and coal. Fossil fuels also must be power? Electric utility companies are continually purchased and refined to use. using mirrors to concentrate heat from the sun to produce environmentally friendly Unlike traditional power plants, concen- electricity for cities, especially in the trating solar power systems provide an southwestern United States. environmentally benign source of energy, produce virtually no emissions, and con- Photo by Hugh Reilly, Sandia National Laboratories/PIX02186 Photo by Hugh Reilly, This concentrating solar power tower system — known as Solar Two — near Barstow, California, is the world’s largest central receiver plant. This document was produced for the U.S. Department of Energy (DOE) by the National Renewable Energy Laboratory (NREL), a DOE national laboratory.
    [Show full text]
  • On Alternative Energy Hydroelectric Power
    Focus On Alternative Energy Hydroelectric Power What is Hydroelectric Power (Hydropower)? Hydroelectric power comes from the natural flow of water. The energy is produced by the fall of water turning the blades of a turbine. The turbine is connected to a generator that converts the energy into electricity. The amount of electricity a system can produce depends on the quantity of water passing through a turbine (the volume of water flow) and the height from which the water ‘falls’ (head). The greater the flow and the head, the more electricity produced. Why Wind? Hydropower is a clean, domestic, and renewable source of energy. It provides inexpensive electricity and produces no pollution. Unlike fossil fuels, hydropower does not destroy water during the production of electricity. Hydropower is the only renewable source of energy that can replace fossil fuels’ electricity production while satisfying growing energy needs. Hydroelectric systems vary in size and application. Micro-hydroelectric plants are the smallest types of hydroelectric systems. They can generate between 1 kW and 1 MW of power and are ideal for powering smaller services such as processing machines, small farms, and communities. Large hydroelectric systems can produce large amounts of electricity. These systems can be used to power large communities and cities. Why Hydropower? Technical Feasibility Hydropower is the most energy efficient power generator. Currently, hydropower is capable of converting 90% of the available energy into electricity. This can be compared to the most efficient fossil fuel plants, which are only 60% efficient. The principal advantages of using hydropower are its large renewable domestic resource base, the absence of polluting emissions during operation, its capability in some cases to respond quickly to utility load demands, and its very low operating costs.
    [Show full text]