Glossary
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
A
Alternating Current
An alternating current is a flow of electricity that reverses its direction at regular intervals or cycles, unlike a direct current that flows in only one direction. Alternating current is typically abbreviated as AC. In the United States, AC reverses direction 120 times per second.
Ampere
An ampere of "amp" is a unit of measure of an electrical current. One amp is equal to the flow of one coulomb per second or the current produced by one volt across a resistance of one ohm.
B
Barrel (of oil)
A unit of volume equal to 42 U.S. gallons. One barrel weights 306 pounds or 5.80 million Btu of crude oil. Barrel is abbreviated as bbl.
Biodiesel
An alternative fuel that can be made from any fat or vegetable oil. It can be used in any diesel engine with few or no modifications. Although biodiesel does not contain petroleum, it can be blended with diesel at any level or used in its pure form.
Biofuel
Biofuel is any liquid, gas, or solid fuel made from one or more biological materials, including plants, municipal waste, and animal waste. Examples of biofuels are methane , ethanol , and biodiesel. Biofuels, unlike fossil fuels are generally classified as renewable fuels.
Biomass
Biomass is any biological material from recently living organisms including, but not limited to plants, animals, and agricultural waste. Biomass is the term generally used in reference to input materials in the biofuel production process. Biomass is generally classified as a renewable energy source. Biomass may be a by-product of other processes such as biodegradable wastes from agriculture, forestry, and municipal landfills. Biomass may also be specifically grown for biofuel production. Examples of biomass products grown for biofuel production include corn, soybeans, rapeseed, sugar beet, and sugar cane.
Bitumen
Bitumen is a flammable mixture of hydrocarbons. Bitumens may range from solids to light volatile naphtha. Bitumens can exist naturally or can be made by distilling coal or petroleum.
Boiling Water Reactor
A boiling water reactor is a nuclear reactor in which water is allowed to boil in the core. The resulting steam is used to drive a turbine generating electric power.
British Thermal Unit (Btu)
The amount of heat required to raise the temperature of one pound of water one degree Fahrenheit; equal to 252 calories.
C
Calorie
A unit for measuring heat energy. This unit is equal to 4.184 joules. Often used instead of joules when dealing with the energy released from food.
Carbon
Carbon is an abundant non-metallic element. Carbon's symbol is C and its atomic number is 6. It occurs in all organic compounds. It naturally exists in three forms, diamond, graphite, and amorphous. Diamond and graphite are pure forms of carbon. Carbon is a major component of coal, oil, and crude oil.
Carbon Dioxide
Carbon dioxide is a chemical compound with the formula CO2. Each molecule of carbon dioxide consists of one carbon atom and two oxygen atoms. At room temperature, CO2 is a gas. When frozen, CO2 becomes a solid also called "dry ice." Carbon dioxide may be produced by several means, including organic and inorganic. It is produced by the respiration of living organisms. It is also produced when organic materials decompose or are combusted. CO2 is used by plants in the photosynthesis process. Carbon dioxide is considered a greenhouse gas, due in part because of its capacity to absorb infrared light.
Carbon Sequestration
Carbon sequestration is the intentional long-term storage of carbon to prevent its release into the atmosphere as carbon dioxide. There are two types of carbon sequestration: terrestrial and geologic. Terrestrial carbon sequestration may be accomplished through natural processes such as reforestation and crop farming practices. These processes can trap carbon with plants and slow decomposing plants from releasing carbon dioxide into the atmosphere. Geologic sequestration is accomplished by separating and capturing carbon dioxide from industrial and energy-related sources before it enters the atmosphere. The captured carbon is then stored in geologically stable underground or undersea rock formations. This type of carbon sequestration is also referred to as "carbon capture and storage."
Circuit(s)
A circuit is a conductor or a system of conductors through which electric current flows.
Clean Coal
Clean coal refers to a broad range of technologies, processes, and equipment used to reduce, eliminate, or contain specific combustion emissions such as carbon dioxide, sulfur dioxide, and nitrogen oxides. These technologies may "wash" the coal before combustion to reduce emissions and or capture and treat the emissions after combustion.
Climate Change
Climate change is a broad reference to the long-term fluctuations in temperature, precipitation, wind and all other aspects of the Earth's weather. "Global warming" is a common term used to reference an increase in the average temperature of the earth.
Coal Gasification
Coal gasification is the conversion of coal, char, or coke solids to a gas. The process is accomplished by controlled reactions with steam, oxygen, hydrogen, carbon dioxide, air, or a mixture of these. The process can produce hydrogen, methane, and other gases which can be used as synthetic natural gas for fuel and other synthetic gases of chemical and plastic manufacturing processes.
Cogeneration
Cogeneration is the simultaneous generation of electrical energy and heat for other uses. For example, the generation of electricity with the creation of steam which is used for space heating would be cogeneration.
Coke
Coke is the solid residue of coal after destructive distillation (heating in an airless chamber) has removed much of the volatile materials. Coke is primarily carbon. Coke is used a fuel in blast furnace and foundry processes such as steel manufacturing.
D
Direct Current
Direct current or "DC" is a flow of electricity the moves in only one direction through the circuit, unlike an alternating current where the electricity flows in both directions. The electricity from a battery is an example of DC.
E
Electricity
Electricity is energy characterized by the movement of charged particles generated by friction, induction, or chemical change.
Electricity Generation
Electricity generation is the process of producing electric energy by transforming or converting other forms of energy. Electricity generation is commonly expressed as generation capacity and measured in kilowatts (kW) or megawatt (MW).
Electron
An electron is a subatomic particle with a negative electric charge. Electrons form part of an atom and move around its nucleus.
Energy
Energy is the ability to do work or the ability to move an object. Electrical energy is usually measured in kilowatt hours (kWh), while heat energy is usually measured in British thermal units (Btu).
Energy Education
Energy education is the interdisciplinary instruction of all aspects of energy including creation, distribution, use, economics, and policy. Instruction ranges from primary education through graduate degree granting programs. Among the disciplines of energy education are chemical, mechanics, biology, sociology, systems design, environmental science, economics, public policy, civil engineering, and architecture. Energy education includes the release and dispersing of the results of energy related research. Energy education also includes focused instruction and research assistance for professional and policymakers seeking specific information regarding energy.
Energy Efficiency
Energy efficiency in an entirely technical sense refers to the comparison of the amount of fuel (including, but not limited to electricity, gas, oil, solar, or wind) input into an appliance or system relative to the output achieved. The smaller the ratio of energy input to energy out, the greater the energy efficiency.
Energy Policy
Energy policy is the rules, regulations, laws, and technical standards that govern the production, transportation, distribution, sale, and consumption of energy and energy related products and systems. Energy policy affects all aspects of the fuel and electricity cycles. Energy policy affects the exploration for fuel sources, the efficiency requirements of a household hot water heater, the type of fuel used to generate electricity, the price of energy, and more.
Energy Storage
Energy storage generally refers to the temporary containment of electricity or heat in a suitable device or facility that can then release the held electricity or heat on demand. The primary example of energy storage is a battery. Energy storage can be used to make energy more portable or to take advantage of intermittent energy production systems such as wind turbines or photovoltaic systems.
Energy Systems
Energy systems refer to the ways in which power is generated, transmitted, and distributed, to meet industrial and consumer energy needs.
Environmental Assessment and Monitoring
Environmental assessment and monitoring refers to the continual collection of data and use of the collected data in the evaluation of the condition of the environment including but not limited to atmospheric, stratospheric, surface water, sub-surface water, wildlife, surface air, and weather.
Environmental Mitigation
Environmental mitigation is the technology concerned with the reduction of pollution, contamination, and deterioration of the surroundings related to the production of energy. Energy related-environmental mitigation and management research ranges from the study of fossil fuel extraction techniques to power plant emissions and water runoff management.
Ethanol
Ethanol or ethyl alcohol is a flammable colorless liquid solvent at room temperature. Ethanol is produced through the fermentation of sugars or starches or chemical synthesis using ethylene gas and sulfuric or phosphoric acid. Ethanol produced through fermentation produces the alcohol in beer, wine, and liquors. Ethanol is also used in automotive fuels for its clean burning properties.
F
Fischer-Tropsch Process
The Fischer-Tropsch process is a method to convert a hydrogen and carbon monoxide gas mixture from coal or biomass, into liquid hydrocarbon fuels. The exothermic conversion process uses an iron or cobalt catalyst. The process using coal is often referred to as "coal-to-liquids."
Fission
Fission is the splitting apart of atoms. This splitting releases large amounts of energy and one or more neutrons. Nuclear power plants split the nuclei of uranium atoms in a process called fission.
Fossil Fuels
Fossil fuels are the accumulated ancient remains of organic matter that consist largely of carbon and hydrogen (also known as hydrocarbon deposits). Buried organic materials such as plants and animals are converted into fossil fuels by pressure and or heat over geological periods. Fossil fuels can be solid, liquid, or gaseous, including coals, petroleum, heavy oils, bitumens, and natural gas (methane, ethane, and other components). Fossil fuels are used to produce electricity, gasoline, plastics, fertilizers, and many other products. Fossil fuels, currently, account for the largest percentage of the world's energy production. The combustion of fossil fuels produces carbon dioxide and other greenhouse gases.
Fuel Cells
Fuel cells are electrochemical assemblies in which the energy of a reaction between a fuel and an oxidant is converted directly and continuously into electrical energy. Many fuel cells use hydrogen as the fuel source. The hydrogen is converted to electricity and heat. The by-product of the conversion process is water.
Fusion
Fusion is the combining of the nuclei of atoms. Energy from the nuclei of atoms, called "nuclear energy" is released from fusion.
G
Geothermal
Geothermal power is the use of natural heat sources from the Earth to heat or cool indoor environments, generate electricity, or to improve the efficiency of other environmental heating and cool systems. Geothermal energy is collected in a number of ways, including direct use of water from hot springs, electricity generation by power plants built on natural heat reservoirs, and individual building temperature control by geothermal heat pumps that collect or disperse heat using sub-surface piping.
Generating Capacity
Generating (or generation) capacity is the amount of electrical power a power plant can produce. Generation capacity is generally expressed in kilowatts (kW) or megawatts (MW).
Greenhouse Effect
The effect of the Earth's atmosphere, due to certain gases, in trapping heat from the sun; the atmosphere acts like a greenhouse.
Greenhouse Gases
Greenhouse gases trap the heat of the sun in the Earth's atmosphere, producing the greenhouse effect. The two major greenhouse gases are water vapor and carbon dioxide. Lesser greenhouse gases include methane, ozone, chlorofluorocarbons, and nitrogen oxides.
Grid
The grid is nickname for the physical system for electricity transmission and distribution. The grid includes all the components between the generation plant and the local distribution poles such as poles, towers, wires, transformers, and substations.
H
Heat Content
The gross heat content is the number of British thermal units (Btu) produced by the combustion, of a volume of gas under certain with air of the same temperature and pressure as the gas, when the products of combustion are cooled to the initial temperature of gas and air and when the water formed by combustion is condensed to the liquid state.
Hydrocarbon
Hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are abundant in nature and are the principle components in oil.
Hydrogen
Hydrogen is a nonmetallic element, with the atomic symbol H and atomic number 1. Hydrogen is the lightest and most abundant element, but is normally found only in combination with other elements. Hydrogen gas is a highly reactive colorless gas. The most abundant source of hydrogen is water. Hydrogen is used to produce ammonia, refine metals, and other industrial processes. It can also be used as a fuel source for combustion engines.
Hydropower
Hydropower is energy derived from harnessing the kinetic energy of moving water. Hydropower may be as simple as using a flowing stream to turn a paddle wheel that is connected to a rotary machine such as a grain mill. On a larger scale, hydropower is used to turn electricity generating turbines to convert the kinetic energy into electric energy.
I
J
Joule
A joule is the metric unit for measuring work and energy, named after James Joule. It is equal to the work done when a one ampere current is passed through a resistance of one ohm for one second.
K
Kilowatt (kW)
A kilowatt is a unit of power measurement usually used to measure electric power. A kilowatt equals 1000 watts.
Kilowatthour (kWh)
A killowatthour A measure of electricity defined as a unit of work or energy, measured as 1 kilowatt (1,000 watts) of power expended for 1 hour. One kWh is equivalent to 3,412 Btu or 3.6 million joules. Kilowatthour may also be seen written as kilowatt hour or kilowatt-hour.
L
Liquefied Petroleum Gas (LPG)
A group of hydrocarbon-based gases derived from crude oil refining or natural gas fractionation. They include ethane, ethylene, propane, propylene, normal butane, butylene, isobutane, and isobutylene. For convenience of transportation, these gases are liquefied through pressurization.
Load
 The power and energy requirements of users on the electric power system in a certain area or the amount of power delivered to a certain point is referred to as the load.
M
Materials Science
Material science as it relates to energy is the study of the properties and applications of substances used in photovoltaics, electronics, and nanostructures and how advanced functional materials and nanostructures can advance energy efficiency and energy resources.
Megawatt
A megawatt is a unit of electrical power equal to 1000 kilowatts or one million watts.
Methane
Methane is a highly flammable odorless colorless gas at room temperature. It is the primary component of "natural gas," approximately 97% by volume. The chemical symbol for methane is CH4. Methane is classified as a greenhouse gas, however when combusted it burns relatively cleanly as compared to coal or oil.
N
Natural Gas
Natural gas is an odorless, colorless, tasteless, non-toxic clean-burning fossil fuel. It is usually found in fossil fuel deposits and used as a fuel. The primary element of natural gas is methane.
Nuclear Energy
Nuclear energy is power derived from the fission (splitting) or fusion (joining) of atomic nuclei present in radioactive elements, such as uranium and thorium. The fission or fusion produces heat. The heat is turn is used to create sufficient steam to drive the turbines of an electricity generator.
O
Ohm
An Ohm is a unit of resistance to the flow of an electric current.
P
Photovoltaic Cells
A photovoltaic (PV) cell is a device, usually made from silicon, which converts some of the energy from light (radiant energy) into electrical energy. Another name for PV cells is solar cells
Pressurized Water Reactor
A pressurized water reactor is a nuclear reactor in which water, heated by nuclear energy, is kept a high pressure to prevent the water from boiling. Steam is then generated in a secondary coolant loop.
Q
Quadrillion Btu
One quadrillion (1015= 10 to the 15th power) British thermal units (Btu).
R
R-Value
R-value is the measure of a material's resistance to heat flow in units of Fahrenheit degrees by hours by square feet per Btu. The higher the R-value of a material, the greater its insulating capability.
Reactor Core
The reactor core is the part of a nuclear power plant that houses the nuclear fuel assemblies and where the nuclear fission occurs.
Renewable Fuels
Renewable fuels are fuels that are generally considered to be infinitely abundant or that can easily replenished on an infinite or nearly infinite scale relative to fossil fuels that are considered non-renewable. Examples of renewable fuels include sunlight, wind, biomass, and ocean waves. Sunlight is infinitely abundant. Biomass may be nearly infinitely replenished through agricultural operations.
S
Short ton
A unit of weight equal to 2,000 pounds often used to measure coal.
Solar Cell
A solar cell is a device that changes radiant energy from the sun into electrical energy by the photovoltaic process.
Solar Energy
Solar energy refers to the conversion of sunlight into useable heat or electricity. Solar energy may be used passively through methods such as building designs that place windows and water heating elements to take advantage of the solar energy properties of sunlight. Active solar energy use involves the conversion of sunlight into electrical energy either through the photovoltaic effect, or the collection of solar heat to produce steam to run an electricity generator.
Spent Fuel
Spent fuel is leftover material used to fuel a nuclear reactor. The fuel assemblies remain radioactive and must be stored as radioactive waste or reprocessed for additional use. A common unit of measurement for spent fuel is either in metric tons of heavy metal.
T
Transmission (Electric)
Transmission is the movement or transfer of electric energy at high voltages over an interconnected group of lines and associated equipment between points of supply and points at which it is transformed (or stepped down in voltage) for distribution to consumers.
Transportation
Transportation is any means of carrying something (e.g. people, goods, animals, natural gas) from one location to another. The study of transportation includes automotive design, fuel research, environmental science, civil engineering, and urban planning among other disciplines. Transportation systems include highways, railroads, waterways, pipelines, electrical transmission lines, airways, public transits operations, long-haul trucking operations, private automobiles, and bicycle paths among others.
U
Uranium
Uranium is a radioactive heavy metal element. The atomic symbol for uranium is U and it number on the periodic table is 92. Uranium has 14 known isotopes. U238 is the most abundant naturally occurring uranium isotope. Uranium can be processed for use as a nuclear fuel.
V
Volt (V)
The volt is the International System of Units (SI) measure of electric potential or electromotive force. A potential of one volt appears across a resistance of one ohm when a current of one ampere flows through that resistance. Reduced to SI base units, 1 V = 1 kg times m2 times s-3 times A-1 (kilogram meter squared per second cubed per ampere).
Voltage
Voltage is the difference in electrical potential between any two conductors or between a conductor and ground. It is a measure of the electric energy per electron that electrons can acquire and/or give up as they move between the two conductors.
W
Wind Energy
Wind energy is the conversion of air currents into electricity. Generally, wind energy is captured by the blades of windmill or turbine. The blades or turbine are connected to electricity generators. Without the use of energy storage , the availability of wind energy is dependent upon weather conditions. Most wind turbines only operate when the wind speed is within a specified range. The power available from wind is limited by the size of the turbine blades and the velocity of the wind.
Watt
A watt is a metric unit of power, usually used in electric measurements, which gives the rate at which work is done or energy used.
X
Y
Z
Yellowcake
Yellowcake is a uranium concentrate with yellow color and cake like texture. Yellowcake is generally between 70 and 90 percent uranium oxide (U3O8 ). Yellowcake is used in the nuclear power plant fuel enrichment and fabrication process