Overview of Energy Usage in the United States and the World

CHAPTER ONE Overview of Energy Usage in the United States and the World To begin, take a moment to stop and listen. Try to observe Understanding Energy all sounds: the tick of a clock, the hum of a computer, the whirl of a passing car, the whisper of a heater, or perhaps Energy, by definition, is the ability to do work on a physi- the growl of an airplane overhead. These sounds, so com- cal system. Yet, what does this really mean? Since energy is mon that they often go unnoticed, would likely sound the capacity to do work, one must first understand the con- thunderous to societies living 200 years ago. What makes cept of work. Work is defined as force multiplied by dis- society today so different from those historical societies? tance. A force alone is not enough to constitute work; it must be combined with a movement, a term equivalent to The answer is simple: fossil fuel. The availability of easily accessible and cheap energy has the distance component of the equation. Consider the breathed technological life into society. It has influenced example of someone pushing a shopping cart and running the way we transport ourselves, the houses we live in, the into a wall. No matter how hard this person pushes the cart offices we work in, the classrooms we study in, and even the or how much force he or she exerts, if the cart is not chang- food we eat. Energy has single-handedly changed the face ing position then no work is being done. Therefore, a source of society from one of short walking commutes, locally of energy needs to allow for both force and motion. In addi- farmed foods, and face-to-face personal communication tion, this energy source must be replaced to maintain the to a society where travel distances are unlimited, fresh work that is occurring. The energy is replaced in a car by foods are always available regardless of season, and commu- filling the tank with gasoline, or in a body by eating food, nication, over even vast distances, is instantaneous and such as an apple. The apple is a source of energy because it done using battery-operated handheld devices. Although provides nutrients powering the body with food calories these technological changes have led to a society of con- and allowing for continued work. venience, they have not come without cost to our energy Energy is measured in many different ways. In the previ- supply, our food security, national security, and the ous example of food, energy was measured as the number environment. of food calories in the apple. Food calories are really kilo- Today, fossil-fuel-based energy is critical to sustaining calories (and take the capitalized form, Calories); one Calo- the lifestyle that many countries have become accustomed rie is equal to 1,000 calories. A calorie is defined as the to. And the numbers can be overwhelming; today in 2015 amount of energy that will raise the temperature of one we burn 93 million barrels of oil per day, or 1.4 trillion gal- gram of water by one degree Celsius. In addition to the food lons of oil per year, and oil is only about one-third of the calorie and calorie, there are many other metrics of energy energy we consume every year. To maintain this level, let important to our understanding of the concept of energy as alone allow for increased energy use, we will need to shown in Table 1. Energy is often measured in terms of develop new alternative sources of energy if we are going joules. A joule is equivalent to a Newton times a meter to preserve this lifestyle and prevent further reduction to (remember force times distance). In this book, energy will energy supply, security, and the environment. As a basis for also be referred to in British thermal units (BTU). A BTU is this entire book, this introductory chapter will explore the equivalent to 1,055 joules and is often used when discuss- basic concepts of energy production and utilization and its ing energy sources used to heat water or other substances. critical role in modern society. In many cases, energy is produced or consumed at such a 1 table 1 Energy conversion units J kWh BTU kcal 1 joule (J) 1 2.8 × 10−7 9.5 × 10−4 2.4 × 10−4 1 kilowatt-hour (kWh) 3.6 × 106 1 3,412 860 1 British thermal unit (BTU) 1,054 2.9 × 10−4 1 0.252 1 kilocalorie (kcal) 4,184 1.2 × 10−3 3.97 1 1 tonne oil equivalent (toe) 4.5 × 1010 11,630 4.2 × 107 1.1 × 107 note: Each publication may discuss energy in terms of different units such as J, BTU, kcal, kWh, and toe. This table is designed to help understand the relationship between these units and allow for the conversion between different energy- related units. data from: APS Panel on Public Affairs (2014). table 2 Comparison of energy content for varying energy sources including fossil fuels and common food sources using differing units of comparison J kWh BTU kcal 1 barrel oil (42 gallons) 6.1 × 109 1,713 5.8 × 106 1,468,800 1 ton coal 2.7 × 1010 7,560 2.5 × 107 6,480,000 1 therm gas 1.1 × 108 29 1.0 × 105 25,200 1 gallon gasoline 1.3 × 108 36.0 1.2 × 105 31,248 1 bushel corn (56 pounds) 8.6 × 107 24.5 8.1 × 104 20,453 1 fast-food hamburger 2.8 × 106 0.8 2.7 × 103 670 data from: APS Panel on Public Affairs (2014); US Department of Energy (2014). large scale that a very large standard of measurement is other substance, the solid wood or coal is broken down and needed. An example of such a large consumption of energy heat and ash are created. As the chemical bonds are broken is the consumption or production of fossil fuels around the within the wood or coal, energy is released in the form of world. Energy on this very large scale is often measured by heat. This heat can be used simply for direct warmth or it comparing it to the burning of 1 ton of petroleum also can be used to heat another substance like water to produce known as a tonne of oil equivalent (toe). One toe is equiva- steam, a key reaction in the production of electrical power. lent to about 42 gigajoules of energy (APS Panel on Public Although a slice of pizza is not burned in the same way that Affairs, 2014). In order to get a better grasp on how these wood or coal is burned, it is also broken down through various energy measurements relate to one another, Table 2 digestion into smaller components like amino acids, carbo- shows energy equivalents of some common energy sources. hydrates, and lipids, changing the pizza’s chemical state. The various ways of measuring energy are due in large This change in chemical state results in the biological com- part to the many different forms of energy. There are fun- ponents needed for metabolic respiration and the creation damentally five forms of energy: chemical, electromag- of adenosine triphosphate (ATP), a molecule that provides netic, mechanical, nuclear, and electrical. The first form of fuel for the reactions occurring within the body. energy, chemical energy, is energy that occurs due to a Electromagnetic energy is another form of energy. Elec- chemical transformation or chemical reaction. The notion tromagnetic energy (or radiation) is the energy of light. Most of a chemical reaction might bring to mind a picture of of the natural light received on Earth comes from the sun. flasks containing colored liquid bubbling over a Bunsen Electromagnetic radiation results from oscillating energy burner. Nevertheless, chemical energy is actually quite var- particles called photons moving in wavelike patterns. These ied and common, and includes things like burning wood in photons are a result of thermonuclear reactions that occur a campfire for warmth or eating a slice of pizza to satisfy within the core of the sun and then radiate outward toward one’s appetite. In the case of burning wood, coal, or any the Earth. Depending on the amount of energy these pho- 2 CHAPTER ONE Visible γ-Rays X-Rays UV IR Microwaves Radiowaves 10–8 10–6 10–4 10–2 1 102 104 λ, cm Gamma (γ-Rays) – Nuclear Fission and Fusion X-Rays – Diagnostic Radiology Ultraviolet (UV) – Formation of Vitamin D and Sunburn Visible – Photosynthesis and Light Infrared Radiation (IR) – Heating, Night Vision, and Short Distance Communication (Remote Controls) Microwaves – Communication, Radar and Power Radiowaves – Communication FIGURE 1.1 Chart showing the wavelength ranges for the various particles of electromagnetic radiation. The amount of energy contained within each of these particles varies based on this wavelength. The longer wavelengths have less energy, while the shorter wavelengths have more energy. Each range of wavelengths has a unique name that can also be associated with different and unique functions. For instance, ultraviolet wavelengths cause sunburns, while radio wavelengths are used for communication. tons contain, the wavelengths change and they are classified production. The first type of nuclear reaction is the fusion as different types of radiation as shown in figure 1.1. For reaction. This reaction takes place in the sun and occurs instance, wavelengths classified as visible radiation (visible when two atomic nuclei fuse to form a single atomic light) allow human beings to see colors, while wavelengths nucleus such as two hydrogen nuclei combining to form a classified as ultraviolet radiation cause their skin to sunburn helium atom.

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