| Glossary | Ch01 Ch02 Ch03 Ch04 Ch05 Ch06 Ch07 Ch08 Ch09 Ch10 Ch11 Ch12 Ch13 Ch14 |
| Chapter 6 | |
| active solar heating system | System that uses solar collectors to capture energy from the sun and store it as heat for space heating and water heating. Liquid or air pumped through the collectors transfers the captured heat to a storage system such as an insulated water tank or rock bed. Pumps or fans then distribute the stored heat or hot water throughout a dwelling as needed. Compare passive solar heating system. |
| alpha particle | Positively charged matter, consisting of two neutrons and two protons, that is emitted as a form of radioactivity from the nuclei of some radioisotopes. See also beta particle, gamma rays. |
| animal manure | Dung and urine of animals used as a form of organic fertilizer. Compare green manure. |
| area strip mining | Type of surface mining used where the terrain is flat. An earthmover strips away the overburden, and a power shovel digs a cut to remove the mineral deposit. After removal of the mineral, the trench is filled with overburden, and a new cut is made parallel to the previous one. The process is repeated over the entire site. Compare dredging, mountaintop removal, open-pit mining, subsurface mining. |
| beta particle | Swiftly moving electron emitted by the nucleus of a radioactive isotope. See also alpha particle, gamma rays. |
| biofuel | Gas or liquid fuel (such as ethyl alcohol) made from plant material (biomass). |
| biomass | Organic matter produced by plants and other photosynthetic producers; total dry weight of all living organisms that can be supported at each trophic level in a food chain or web; dry weight of all organic matter in plants and animals in an ecosystem; plant materials and animal wastes used as fuel. |
| bitumen | Gooey, black, high-sulfur, heavy oil extracted from tar sand and then upgraded to synthetic fuel oil. See tar sand. |
| breeder nuclear fission reactor | Nuclear fission reactor that produces more nuclear fuel than it consumes by converting nonfissionable uranium-238 into fissionable plutonium-239. |
| chain reaction | Multiple nuclear fissions, taking place within a certain mass of a fissionable isotope, that release an enormous amount of energy in a short time. See nuclear. |
| coal | Solid, combustible mixture of organic compounds with 30-98% carbon by weight, mixed with various amounts of water and small amounts of sulfur and nitrogen compounds. It forms in several stages as the remains of plants are subjected to heat and pressure over millions of years. |
| coal gasification | Conversion of solid coal to synthetic natural gas (SNG). |
| coal liquefaction | Conversion of solid coal to a liquid hydrocarbon fuel such as synthetic gasoline or methanol. |
| cogeneration | Production of two useful forms of energy, such as high-temperature heat or steam and electricity, from the same fuel source. |
| contour strip mining | Form of surface mining used on hilly or mountainous terrain. A power shovel cuts a series of terraces into the side of a hill. An earthmover removes the overburden, and a power shovel extracts the coal, with the overburden from each new terrace dumped onto the one below. Compare area strip mining, dredging, mountaintop removal, open-pit mining, subsurface mining. |
| core | Inner zone of the earth. It consists of a solid inner core and a liquid outer core. Compare crust, mantle. |
| critical mass | Amount of fissionable nuclei needed to sustain a nuclear fission chain reaction. |
| crude oil | Gooey liquid consisting mostly of hydrocarbon compounds and small amounts of compounds containing oxygen, sulfur, and nitrogen. Extracted from underground accumulations, it is sent to oil refineries, where it is converted to heating oil, diesel fuel, gasoline, tar, and other materials. |
| deuterium (D; hydrogen-2) | Isotope of the element hydrogen, with a nucleus containing one proton and one neutron and a mass number of 2. |
| discount rate | Economic value a resource will have in the future compared with its present value. |
| economic depletion | Exhaustion of 80% of the estimated supply of a nonrenewable resource. Finding, extracting, and processing the remaining 20% usually costs more than it is worth; may also apply to the depletion of a renewable resource, such as a fish or tree species. |
| energy efficiency | Percentage of the total energy input that does useful work and is not converted into low-quality, usually useless heat in an energy conversion system or process. See energy quality, net energy. Compare material efficiency. |
| exhaustible resource | See nonrenewable resource. |
| external cost | Harmful environmental or social effect of producing and using an economic good that is not included in the market price of the good. Compare external benefit, full cost, internal cost. |
| fissionable isotope | Isotope that can split apart when hit by a neutron at the right speed and thus undergo nuclear fission. Examples are uranium-235 and plutonium-239. See nuclear fission. |
| fossil fuel | Products of partial or complete decomposition of plants and animals that occur as crude oil, coal, natural gas, or heavy oils as a result of exposure to heat and pressure in the earth's crust over millions of years. See coal, crude oil, natural gas. |
| fossils | Skeletons, bones, shells, body parts, leaves, seeds, or impressions of such items that provide recognizable evidence of organisms that lived long ago. |
| full cost | Cost of a good when its internal costs and its estimated short- and long-term external costs are included in its market price. Compare external cost, internal cost. |
| gangue | Waste or undesired material in an ore. See ore. |
| geothermal energy | Heat transferred from the earth's underground concentrations of (1) dry steam (steam with no water droplets), (2) wet steam (a mixture of steam and water droplets), or (3) hot water trapped in fractured or porous rock. |
| half-life | Time needed for one-half of the nuclei in a radioisotope to emit its radiation. Each radioisotope has a characteristic half-life, which may range from a few millionths of a second to several billion years. See radioisotope. |
| high-quality energy | Energy that is concentrated and has great ability to perform useful work. Examples are high-temperature heat and the energy in electricity, coal, oil, gasoline, sunlight, and nuclei of uranium-235. Compare low-quality energy. |
| hydroelectric power plant | Structure in which the energy of falling or flowing water spins a turbine generator to produce electricity. |
| hydropower | Electrical energy produced by falling or flowing water. See hydroelectric power plant. |
| identified resources | Deposits of a particular mineral-bearing material of which the location, quantity, and quality are known or have been estimated from direct geological evidence and measurements. Compare undiscovered resources. |
| internal cost | Direct cost paid by the producer and the buyer of an economic good. Compare external benefit, external cost, full cost. |
| ionizing radiation | Fast-moving alpha or beta particles or high-energy radiation (gamma rays) emitted by radioisotopes. They have enough energy to dislodge one or more electrons from atoms they hit, forming charged ions in tissue that can react with and damage living tissue. Compare nonionizing radiation. |
| kerogen | Solid, waxy mixture of hydrocarbons found in oil shale rock. Heating the rock to high temperatures causes the kerogen to vaporize. The vapor is condensed, purified, and then sent to a refinery to produce gasoline, heating oil, and other products. See also oil shale, shale oil. |
| kilowatt (kW) | Unit of electrical power equal to 1,000 watts. See watt. |
| life cycle cost | Initial cost plus lifetime operating costs of an economic good. Compare full cost. |
| liquefied natural gas (LNG) | Natural gas converted to liquid form by cooling to a very low temperature. |
| liquefied petroleum gas (LPG) | Mixture of liquefied propane (C3H8) and butane (C4H10) gas removed from natural gas and used as a fuel. |
| LPG | See liquefied petroleum gas. |
| manure | See animal manure, green manure. |
| meltdown | Melting of the core of a nuclear reactor. |
| micropower systems | Systems of small-scale decentralized units that generate 1-10,000 kilowatts of electricity. Examples include (1) microturbines, (2) fuel cells, and (3) household solar panels and solar roofs. |
| mineral | Any naturally occurring inorganic substance found in the earth's crust as a crystalline solid. See mineral resource. |
| mineral resource | Concentration of naturally occurring solid, liquid, or gaseous material in or on the earth's crust in a form and amount such that extracting and converting it into useful materials or items is currently or potentially profitable. Mineral resources are classified as metallic (such as iron and tin ores) or nonmetallic (such as fossil fuels, sand, and salt). |
| mountaintop removal | Type of surface mining that uses explosives, massive shovels, and even larger machinery called draglines to remove the top of a mountain to expose seams of coal underneath a mountain. Compare area strip mining, contour strip mining. |
| natural gas | Underground deposits of gases consisting of 50-90% by weight methane gas (CH4) and small amounts of heavier gaseous hydrocarbon compounds such as propane (C3H8) and butane (C4H10). |
| natural ionizing radiation | Ionizing radiation in the environment from natural sources. See ionizing radiation. |
| natural radioactive decay | Nuclear change in which unstable nuclei of atoms spontaneously shoot out particles (usually alpha or beta particles) or energy (gamma rays) at a fixed rate. |
| net energy | Total amount of useful energy available from an energy resource or energy system over its lifetime, minus the amount of energy (1) used (the first law of thermodynamics), (2) automatically wasted (the second law of thermodynamics), and (3) unnecessarily wasted in finding, processing, concentrating, and transporting it to users. |
| nonionizing radiation | Forms of radiant energy such as radio waves, microwaves, infrared light, and ordinary light that do not have enough energy to cause ionization of atoms in living tissue. Compare ionizing radiation. |
| nonrenewable resource | Resource that exists in a fixed amount (stock) in various places in the earth's crust and has the potential for renewal by geological, physical, and chemical processes taking place over hundreds of millions to billions of years. Examples are copper, aluminum, coal, and oil. We classify these resources as exhaustible because we are extracting and using them at a much faster rate than they were formed. Compare renewable resource. |
| nuclear change | Process in which nuclei of certain isotopes spontaneously change, or are forced to change, into one or more different isotopes. The three principal types of nuclear change are natural radioactivity, nuclear fission, and nuclear fusion. Compare chemical change, physical change. |
| nuclear energy | Energy released when atomic nuclei undergo a nuclear reaction such as the spontaneous emission of radioactivity, nuclear fission, or nuclear fusion. |
| nuclear fission | Nuclear change in which the nuclei of certain isotopes with large mass numbers (such as uranium-235 and plutonium-239) are split apart into lighter nuclei when struck by a neutron. This process releases more neutrons and a large amount of energy. Compare nuclear fusion. |
| nuclear fusion | Nuclear change in which two nuclei of isotopes of elements with a low mass number (such as hydrogen-2 and hydrogen-3) are forced together at extremely high temperatures until they fuse to form a heavier nucleus (such as helium-4). This process releases a large amount of energy. Compare nuclear fission. |
| oil | See crude oil. |
| oil shale | Fine-grained rock containing various amounts of kerogen, a solid, waxy mixture of hydrocarbon compounds. Heating the rock to high temperatures converts the kerogen into a vapor that can be condensed to form a slow-flowing heavy oil called shale oil. See kerogen, shale oil. |
| open-pit mining | Removing minerals such as gravel, sand, and metal ores by digging them out of the earth's surface and leaving an open pit. Compare area strip mining, contour strip mining, dredging, mountaintop removal, subsurface mining. |
| ore | Part of a metal-yielding material that can be economically and legally extracted at a given time. An ore typically contains two parts: the ore mineral, which contains the desired metal, and waste mineral material (gangue). |
| other resources | Identified and undiscovered resources not classified as reserves. Compare identified resources, reserves, undiscovered resources. |
| overburden | Layer of soil and rock overlying a mineral deposit. Surface mining removes this layer. |
| passive solar heating system | System that captures sunlight directly within a structure and converts it into low-temperature heat for space heating or for heating water for domestic use without the use of mechanical devices. Compare active solar heating system. |
| petrochemicals | Chemicals obtained by refining (distilling) crude oil. They are used as raw materials in manufacturing most industrial chemicals, fertilizers, pesticides, plastics, synthetic fibers, paints, medicines, and many other products. |
| petroleum | See crude oil. |
| photovoltaic cell (solar cell) | Device which converts radiant (solar) energy directly into electrical energy. |
| radioactive decay | Change of a radioisotope to a different isotope by the emission of radioactivity. |
| radioactive isotope | See radioisotope. |
| radioactive waste | Waste products of nuclear power plants, research, medicine, weapon production, or other processes involving nuclear reactions. See radioactivity. |
| radioactivity | Nuclear change in which unstable nuclei of atoms spontaneously shoot out "chunks" of mass, energy, or both at a fixed rate. The three principal types of radioactivity are gamma rays and fast-moving alpha particles and beta particles. |
| radioisotope | Isotope of an atom that spontaneously emits one or more types of radioactivity (alpha particles, beta particles, gamma rays). |
| reserve-to-production ratio | Number of years reserves of a particular nonrenewable mineral will last at current annual production rates. See reserves. |
| shale oil | Slow-flowing, dark brown, heavy oil obtained when kerogen in oil shale is vaporized at high temperatures and then condensed. Shale oil can be refined to yield gasoline, heating oil, and other petroleum products. See kerogen, oil shale. |
| smelting | Process in which a desired metal is separated from the other elements in an ore mineral. |
| solar cell | See photovoltaic cell. |
| solar collector | Device for collecting radiant energy from the sun and converting it into heat. See active solar heating system, passive solar heating system. |
| strip mining | Form of surface mining in which bulldozers, power shovels, or stripping wheels remove large chunks of the earth's surface in strips. See area strip mining, contour strip mining, surface mining. Compare subsurface mining. |
| subsurface mining | Extraction of a metal ore or fuel resource such as coal from a deep underground deposit. Compare surface mining. |
| superinsulated house | House that is heavily insulated and extremely airtight. Typically, active or passive solar collectors are used to heat water, and an air-to-air heat exchanger is used to prevent buildup of excessive moisture and indoor air pollutants. |
| surface mining | Removing soil, subsoil, and other strata and then extracting a mineral deposit found fairly close to the earth's surface. See area strip mining, contour strip mining, mountaintop removal, open-pit mining. Compare subsurface mining. |
| synfuels | Synthetic gaseous and liquid fuels produced from solid coal or sources other than natural gas or crude oil. |
| synthetic natural gas (SNG) | Gaseous fuel containing mostly methane produced from solid coal. |
| tar sand | Deposit of a mixture of clay, sand, water, and varying amounts of a tarlike heavy oil known as bitumen. Bitumen can be extracted from tar sand by heating. It is then purified and upgraded to synthetic crude oil. See bitumen. |
| true cost | See full cost. |
| undiscovered resources | Potential supplies of a particular mineral resource, believed to exist because of geologic knowledge and theory, although specific locations, quality, and amounts are unknown. Compare identified resources, reserves. |
| watt | Unit of power, or rate at which electrical work is done. See kilowatt. |
| wind farm | Cluster of small to medium-sized wind turbines in a windy area to capture wind energy and convert it into electrical energy. |