Glossary
AC See Alternating Current.
Acceleration The rate of change of velocity with time.
Adiabatic Process A thermodynamic process in which the net heat transfer to or from the working fluid is zero.
Alternating Current Electrical current that alternates directions in a repetitive pattern.
Anaerobic Environment An environment that does not contain any oxygen.
Atomic Vapor Laser Isotope Separation A method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions.
Auto Refrigeration A process in which liquefied natural gas (LNG) is kept at its boiling point so that any heat that is conducted through the tanker walls is countered by the latent heat of vaporization, energy that is lost from the LNG as it vaporizes.
AVLIS See Atomic Vapor Laser Isotope Separation.
Bagasse The fibrous matter that remains after sugarcane or sorghum stalks are crushed to extract their juice. It is currently used as a biofuel and in the manufacture of pulp and paper products and building materials.
Base Gas The volume of gas intended as permanent inventory in a gas storage reservoir needed to maintain adequate pressure and flow rates throughout the winter withdrawal season. It is also called cushion gas.
Betz Law The theory which details the maximum possible energy to be derived from a wind turbine. According to Betz's law, no turbine can capture more than 59.3% of the kinetic energy in wind.
Betz Limit See Betz Law.
Binary Cycle Power Plants A type of geothermal power plant that allows cooler geothermal reservoirs to be used than with dry steam and flash steam plants.
Biomass Biological material from living, or recently living, organisms. As an energy source, it can either be used directly or converted into other energy products such as biofuel.
Breeder Reactor A nuclear reactor that is capable of generating more fissile material than it consumes because its neutron energy is high enough to breed fissile from fertile material like uranium-238 and thorium 232.
Caloric Theory of Heat An obsolete scientific theory that heat consists of a self-repellent fluid called caloric that flows from hotter bodies to colder bodies.
Calorie A unit of energy of French origin that, as originally defined, was the amount of energy needed to heat 1 g of water by 1 °C. Its value can vary depending on the temperature.
Cap and Trade An environmental policy tool that delivers results with a mandatory cap on emissions while providing sources flexibility in how they comply.
Carbon Capture See Carbon Capture and Storage.
Carbon Capture and Storage (CCS) The technology that prevents large quantities of CO2 from being released into the atmosphere during the use of fossil fuel in power generation and other industries. The process is based on capturing CO2 from large point sources and storing it in such a way that it does not enter the atmosphere.
Carbon Dioxide Miscible Flooding The process by which carbon dioxide is injected into an oil reservoir in order to increase the output when extracting oil.
CFCs See Chlorofluorocarbons.
Chlorofluorocarbons Organic compounds that contain carbon, chlorine, and fluorine, produced as a volatile derivative of methane and ethane. They have been implicated in the accelerated depletion of the ozone layer.
Clean Coal Technologies The collection of technologies that are being developed to reduce the environmental impact of coal energy generation. Technologies include chemically washing minerals and impurities from the coal; gasification; treating the flue gases with steam to remove sulfur dioxide; carbon capture and storage technologies to capture the carbon dioxide from the flue gas; and, dewatering lower rank coals (brown coals) to improve the calorific value and thus the efficiency of the conversion into electricity.
Coal-Bed Methane Gas A type of natural gas extracted from coal beds.
Coal to Liquids Technologies Processes for converting coal to liquid fuels.
Compression Ignition Engine An internal combustion engine that uses pressure to initiate ignition to burn the fuel which is injected into the combustion chamber. It was developed by Rudolf Diesel in 1893 and is also known as a diesel engine.
Concentrated Solar Power A type of solar power system that uses mirrors or lenses to concentrate a large area of sunlight, or solar thermal energy, onto a small area.
Conduction The transfer of heat between two substances that are in direct contact with one another.
Conservation of Energy The law which states that the total amount of energy in an isolated system will remain constant over time.
Conservation of Mass The law which states that the mass of an isolated system (closed to all matter and energy) will remain constant over time.
Conservation of Momentum The law which states that if no external force acts on a closed system of objects, the momentum of the closed system will remain constant.
Convection The primary method by which heat moves through gases and liquids. It is essentially the up and down movement of gases and liquids caused by heat transfer.
Critical Point The set of conditions under which the properties of a liquid and its vapor become identical.
Critical Pressure The pressure required to liquefy a gas at its critical temperature.
Critical Temperature The temperature at and above which the vapor of a substance cannot be liquefied, no matter how much pressure is applied.
CSAPR The U.S. Environmental Protection Agency's Cross-State Air Pollution Rule that is due to take effect in 2014.
CSP See Concentrated Solar Power.
Cushion gas See Base Gas.
DC See Direct Current.
Dew Point The temperature at which humid air must be cooled, at constant barometric pressure, for water vapor to condense into liquid water. The condensed water is called dew when it forms on a solid surface.
Direct Current The unidirectional flow of electric charge.
Dry Steam Plants Plants that produce energy directly from the steam that emerges at the earth’s surface.
EIA See U.S. Energy Information Administration.
Electric Power Research Institute The independent, nonprofit organization that conducts research and development relating to the generation, delivery and use of electricity for the benefit of the public.
Electromagnetic Force The fundamental force that is associated with electric and magnetic fields and is responsible for atomic structure, chemical reactions, the attractive and repulsive forces associated with electrical charge and magnetism and all other electromagnetic phenomena. It is carried by the photon.
Endothermic Reaction Chemical reactions that must absorb energy in order to proceed. Endothermic reactions cannot occur spontaneously. Work must be done in order to get these reactions to occur. When endothermic reactions absorb energy, a temperature drop is measured during the reaction. Endothermic reactions are characterized by positive heat flow (into the reaction) and an increase in enthalpy.
Energy The ability a physical system has to do work on other physical systems. Given that work is defined as a force acting through a distance (a length of space), energy is always equivalent to the ability to exert pulls or pushes against the basic forces of nature, along a path of a certain length.
Enhanced Geothermal Systems A type of system in which heat is extracted by creating a subsurface fracture system to which water can be added through injection wells. Creating an enhanced or engineered geothermal system requires improving the natural permeability of rock.
Enhanced Oil Recovery The techniques that can be used to increase the amount of crude oil that can be extracted from an oil field. It may also be termed improved oil recovery or tertiary recovery.
Enthalpy The measure of the total energy of a thermodynamic system.
Entropy The thermodynamic property that can be used to determine the energy not available for work in a thermodynamic process. It is defined as the heat transferred divided by the temperature at which it is transferred.
EOR See Enhanced Oil Recovery.
EPRI See Electric Power Research Institute.
Exothermic Reaction Chemical reactions that release energy in the form of heat, light, or sound. Exothermic reactions may occur spontaneously and result in higher randomness or entropy of the system. They are denoted by a negative heat flow (heat is lost to the surroundings) and decrease in enthalpy.
External Combustion Engine A type of heat engine where an internal working fluid is heated by combustion in an external source, through the engine wall or a heat exchanger.
Fast Breeder Reactor A nuclear reactor that utilizes fast neutrons to split atoms of uranium or thorium as part of the process. Fast neutrons have an energy level of approximately 1 MeV (100 TJ/kg), resulting from a particular neutron velocity of 14,000 km/s. Like all breeder reactors it is capable of generating more fissile material than it consumes because it generates additional neutrons that are able to breed fissile atoms from fertile material like uranium-238 and thorium-232.
Federal Energy Regulatory Commission The independent agency that regulates the interstate transmission of electricity, natural gas, and oil. The agency also reviews proposals to build LNG terminals and interstate natural gas pipelines as well as licensing hydropower projects.
FERC See Federal Energy Regulatory Commission.
First Law of Thermodynamics The law which dictates the specifics for the movement of heat and work. Energy cannot be created or destroyed; it can only be transformed from one type of energy to another. The total energy output (as that produced by a machine) is equal to the amount of heat supplied. As energy (generally) can neither be created nor destroyed, the sum of mass and energy is always conserved.
Fischer-Tropsch Synthesis A set of chemical reactions that convert a mixture of carbon monoxide and hydrogen into liquid hydrocarbons.
Flash Steam Plant The most common form of geothermal power plant where hot water is pumped under great pressure to the surface. When it reaches the surface, the pressure is reduced and as a result some of the water changes to steam. This produces a “blast” of steam. The cooled water is returned to the reservoir to be heated by geothermal rocks again.
Flue Gas The gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler, or steam generator.
Force Any influence that causes an object to undergo a change in speed, a change in direction or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity or which can cause a flexible object to deform.
Fracking See Hydraulic Fracturing Process.
Fracture Stimulation The technology that enables natural gas producers to safely and effectively recover natural gas from hard-to-produce resources trapped in deep shale and other unconventional formations thousands of feet below ground.
F-T synthesis See Fischer-Tropsch Synthesis.
Fuel Cells the device that converts chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent.
Futures Contracts A standardized contract between two parties to exchange a specified asset of standardized quantity and quality for a price agreed today (the futures price or the strike price) with delivery occurring at a specified future date, the delivery date.
Gas Centrifuge The device that performs isotope separations of gas.
Gas Condensate The light, oil-like liquid that drops out of the gas when the pressure drops below the dew point.
GDP See Gross Domestic Product.
Geothermal Energy Thermal energy generated and stored in the earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals.
Geothermal Heat Pump A central heating and/or cooling system that pumps heat to or from the ground.
Global Warming The rising average temperature of the earth’s atmosphere and oceans and its projected continuation.
Gravity The natural phenomenon by which physical bodies attract with a force proportional to their mass.
Greenhouse Gases Gases in the atmosphere that absorb and emit radiation within the thermal infrared range. The primary greenhouse gases in the earth's atmosphere are water vapor, carbon dioxide, methane, nitrous oxide, and ozone.
Gross Domestic Product The market value of all final goods and services produced within a country in a given period.
Ground Source Heat Pumps See Geothermal Heat Pumps.
GSHP See Ground Source Heat Pumps.
Heavy Water Water that is chemically the same as regular (light) water, but with the two hydrogen atoms (as in H2O) replaced with deuterium atoms (hence the symbol D2O).
Horizontal Drilling A type of drilling in which the borehole is drilled at least 80° from vertical so that it penetrates a productive formation in a manner parallel to the formation.
Hubberts Peak Theory M. King Hubbert’s theory that for any given geographical area, the production rate of any finite resource (such as petroleum, coal, or any mineral) tends to follow a bell-shaped curve. It is based on the observation that, because the resource amount in any region is finite, the rate of discovery which initially increases quickly must reach a maximum and decline following a bell-shaped curve.
Hydraulic Fracturing Process A process in which water, chemicals, and proppant material are pumped into the well to release the gas trapped in low permeability formations by creating fractures in the rock and allowing oil or natural gas to flow from the rock into the well.
Hydroelectric Power The production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy. It is also termed Hydroelectricity.
IGCC See Integrated Gasification Combination Cycle.
Integrated Gasification Combination Cycle The technology that turns coal into gas-synthesis gas (syngas). It then removes impurities from the coal gas before it is combusted and attempts to turn any pollutants into re-usable by-products. This results in lower emissions of sulfur dioxide, particulates, and mercury.
Internal Combustion Engine A type of heat engine where the combustion of a fuel (normally a fossil fuel) occurs with an oxidizer (usually air) in a combustion engine.
International Organization for Standardization The organization that is the world’s largest developer and publisher of international standards.
In-Situ Leaching The mining process that is used to recover minerals such as copper and uranium through boreholes drilled into a deposit, in-situ.
Isentropic Process A thermodynamic process that takes place from initiation to completion without an increase or decrease in the entropy of the system. In other words, the entropy of the system remains constant.
ISL See In-Situ Leaching.
ISO See International Organization for Standardization.
Kyoto Accord The international treaty whereby countries agree to reduce the amount of greenhouse gases they emit if their neighbors do likewise.
Liquefied Natural Gas Natural gas that has temporarily been converted to liquid form for ease of storage or transport.
LNG See Liquefied Natural Gas.
MEA See Monoethanolamine.
Mine Safety and Health Administration The federal enforcement agency responsible for the health and safety of the nation's miners.
MLIS See Molecular Laser Isotope Separation.
Molecular Laser Isotope Separation The method of isotope separation where specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions of uranium hexafluoride molecules.
Monoethanolamine An organic chemical compound that is both a primary amine and a primary alcohol (due to a hydroxyl group). Like other amines, monoethanolamine acts as a weak base. It is often used to remove carbon dioxide from flue gas.
MSHA See Mine Safety and Health Administration.
NAFTA See North American Free Trade Agreement.
National Oceanic and Atmospheric Administration A scientific agency within the U.S.Department of Commerce that is focused on the conditions of the oceans and the atmosphere.
Newton’s Laws of Motion The three laws of motion composed by Sir Isaac Newton. The first law states that an object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. The second law explains how the velocity of an object changes when it is subjected to an external force. The third law states that for every action (force) in nature there is an equal and opposite reaction.
NOAA See National Oceanic and Atmospheric Administration.
North American Free Trade Agreement The agreement signed by the governments of Canada, Mexico, and the United States to create a trilateral trade bloc in North America.
Nuclear Fission Either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), and releasing a very large amount of energy.
Nuclear Force The force between two or more nucleons. It is responsible for the binding of protons and neutrons into atomic nuclei. The energy released causes the masses of nuclei to be less than the total mass of the protons and neutrons which form them.
Nuclear Fusion The process by which two or more atomic nuclei join together, or “fuse,” to form a single heavier nucleus. This is usually accompanied by the release or absorption of large quantities of energy.
Nuclear Power The use of sustained nuclear fission to generate heat and electricity.
Occupational Safety and Health Administration The main federal agency charged with the enforcement of safety and health legislation.
Octane Rating The standard measure of the performance of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand before detonating. In broad terms, fuels with a higher octane rating are used in high-compression engines that generally have higher performance.
OPEC See Organization Of The Petroleum Exporting Countries.
Operating Temperature The temperature at which an electrical or mechanical device operates.
Organization of the Petroleum Exporting Countries The global organization that is dedicated to stability in and shared control of the petroleum markets.
OSHA See Occupational Safety and Health Administration.
Otto Cycle Engine A type of internal combustion engine in which the piston completes four separate strokes—intake, compression, power, and exhaust—during two separate revolutions of the engine's crankshaft and one single thermodynamic cycle.
Oxy-Fuel Combustion The process of burning a fuel using pure oxygen instead of air as the primary oxidant.
Partial Oxidation A process that is used to convert natural gas to syngas.
Peak Oil The point in time when the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline. This concept is based on the observed production rates of individual oil wells, projected reserves and the combined production rate of a field of related oil wells.
Peak Oil Theory The theory proposed by M. King Hubert that any finite resource—oil, gas, coal, or uranium—follows a bell-shaped curve in its production history. At some point, it reaches a peak and begins to decline, and the decline in production will mirror the rise in production on the way up. The peak production rate and the timing of the peak production depend on the total reserves that exist and are to be discovered in the future.
PEM Fuel Cells See Proton Exchange Membrane Fuel Cell.
Permeability The measure of the ease with which a fluid can move through a porous rock.
Photoelectric effect The principle which states that when a photon of light strikes a solar cell, its energy is transferred to an electron in the semiconductor material in the top layer. If enough energy is absorbed by the electron, it can escape from its normal position in the atom.
Photovoltaic The method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect.
Photovoltaic effect The creation of voltage or electric current in a material upon exposure to light.
Porosity The measure of how much rock is an open space or a void. This space can be between grains or within cracks or cavities of the rock.
Produced Water The term used in the oil and gas industry to describe the water that is produced along with the oil and gas.
Proppants Particles of a particular size that are mixed with fracturing fluid to hold fractures open after a hydraulic fracturing treatment. The most common proppant is sand coated with resin, but other proppants can be aluminum bauxite or special ceramics.
Proton Exchange Membrane Fuel Cell A type of fuel cell that is being developed for transport applications as well as for stationary fuel cell applications and portable fuel cell applications.
Pumped Storage The wind power storage method where the excess energy generated while the wind is blowing is used to pump water from a low-lying reservoir uphill to a higher reservoir. When the wind is not blowing, the water is allowed to flow from the higher reservoir to the lower reservoir, driving a water-powered turbine to generate electricity.
Radiation The process by which electromagnetic waves travel through space. When electromagnetic waves come into contact with an object, heat is transferred to that object.
Rankin Cycle The external combustion steam engine cycle that converts heat from burning fuels such as coal and wood into work. In this case the working fluid is water.
Reserve Life The number of years it would take a country to produce their reserves if they keep producing at the current rates. To obtain this number, you divide their reserves (in barrels) by their producing rate (in barrels/year) to get their reserve life in years.
Ring of Fire An area where large numbers of earthquakes and volcanic eruptions occur in the basin of the Pacific Ocean.
SAGD See Steam-Assisted Gravity Drainage.
Second Law of Thermodynamics The law that puts a limit on how efficient the energy conversion processes can be. It states that it is impossible to convert heat from a heat source totally into work without rejecting some of that heat to a heat sink. There are many alternative statements of the second law of thermodynamics.
Sequestration See Carbon Capture and Sequestration.
Shale The fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable.
Shale Gas Natural gas that is produced from shale.
Slick Water See Slick Water Fracturing.
Slick Water Fracturing A type of fracturing in which chemicals are added to water to lower the viscosity and increase the fluid flow.
Solar Cell A solid-state electrical device that converts the energy of light directly into electricity by the photovoltaic effect.
Solar Collectors Devices that are used to collect heat by absorbing sunlight.
Solar Energy The radiant light and heat from the sun.
Solar Power The conversion of sunlight into electricity, either directly using photovoltaics (PV) or indirectly using concentrated solar power (CSP).
Sour Gas Natural gas or any other gas that contains significant amounts of hydrogen sulfide.
Spot Pricing The price that is quoted for immediate payment and delivery.
Steam-Assisted Gravity Drainage The enhanced oil recovery technology that is used to produce heavy crude oil and bitumen. It is an advanced form of steam stimulation in which a pair of horizontal wells is drilled into the oil reservoir, one a few meters above the other. Low pressure steam is continuously injected into the upper wellbore to heat the oil and reduce its viscosity, causing the heated oil to drain into the lower wellbore, where it is pumped out.
Steam Reforming A process that is used to convert natural gas to syngas. It is carried out in a fired heater with catalyst-filled tubes that produce a syngas with at least 5:1 hydrogen to carbon monoxide ratio. To adjust the ratio, hydrogen can be removed by a membrane or pressure swing adsorption system. This process is widely used if the surplus hydrogen is used in a petroleum refinery or for the manufacture of ammonia in an adjoining plant.
Supercritical Fluid Any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist.
Sweet Gas Natural gas or other gas that does not contain significant amounts of hydrogen sulfide.
Thermodynamic Cycle A series of thermodynamic processes transferring heat and work, while varying pressure, temperature, and other state variables, eventually returning a system to its initial state. In the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine.
Tight Gas Unconventional natural gas which is difficult to access because of the nature of the rock and sand surrounding the deposit.
Tight Oil Petroleum that consists of light crude oil contained in petroleum-bearing formations of relatively low porosity and permeability (shales). It uses the same horizontal well and hydraulic fracturing technology used in the production of shale gas. It should not be confused with oil shale as it differs by the thermal maturity of the oil and the method of extraction.
Towler Principle The principle which states that it not possible to extract energy from the environment without having an impact on the environment.
Trans-Esterfication Reaction The reaction of a triglyceride (fat/oil) with an alcohol to form esters and glycerol.
Triple Point The temperature and pressure of a substance at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.
UCG See Underground Coal Gasification.
Unconventional Oil and Gas Petroleum that is produced or extracted using techniques other than the conventional (oil-well) method. It usually involves the fracture stimulation of very low permeability reservoirs.
Underground Coal Gasification The in-situ gasification process carried out in non-mined coal seams using injection of oxidants and bringing the product gas to surface through production wells drilled from the surface.
Ultrasonic Frequency Generator Any sounds above the frequencies of audible sound and nominally includes anything over 20,000 Hz.
U.S. Department of Energy The government agency whose goal is to advance energy technology and promote related innovation.
U.S. DOE See U.S. Department of Energy.
U.S. Energy Information Administration The government agency that collects, analyzes, and disseminates independent and impartial energy information to promote sound policymaking, efficient markets, and public understanding of energy and its interaction with the economy and the environment.
U.S. Geological Survey The science organization that provides impartial information on the health of our ecosystems and environment, the natural hazards that threaten us, the natural resources we rely on, the impacts of climate and land-use change, and the core science systems that help us provide timely, relevant, and useable information.
USGS See U.S. Geological Survey.
Velocity The speed in a given direction.
Volumetrics The method of determining the amount of oil that was originally in place in a formation by calculating the volume that it occupies.
Wind Power The conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, wind pumps for water pumping or drainage or sails to propel ships.
Wind Turbine A device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator, or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or pumping water, the device is called a windmill, or wind pump.
Work The amount of work done by, or energy transferred, by a force acting through a distance.
Working Gas The volume of gas in a storage gas reservoir above the level of base gas that is available to be withdrawn in the winter. Working gas capacity is equal to the total gas storage capacity minus the base gas.