Glossary
M-N
Last Updated Monday, July 24, 2000
compiled by Nick Sundt


M, N

M

M85. a blend of 85 percent methanol and 15 percent unleaded regular gasoline, used as a motor fuel. (Source: California Energy Commission, 1999a.)

M100. 100 percent (neat) methanol used as a motor fuel in dedicated methanol vehicles, such as some heavy-duty truck engines. (Source: California Energy Commission, 1999a.)

Magma. Molten or partially molten rock at temperatures ranging from 1,260 F to 2,880 F (700 C to 1600 C). Some magma bodies are believed to exist at drillable depths within the Earth's crust, although practical technologies for harnessing magma energy have not been developed. If ever utilized, magma represents a potentially enormous resource. (Source: US Department of Energy, 1999a).

Magnetic Ballast. A type of florescent light ballast that uses a magnetic core to regulate the voltage of a florescent lamp. (Source: US Department of Energy, 1999a).

Make-Up Air. Air brought into a building from outside to replace exhaust air. (Source: US Department of Energy, 1999a).

Manual J. The standard method for calculating residential cooling loads developed by the Air-Conditioning and Refrigeration Institute (ARI) and the Air Conditioning Contractors of America (ACCA) based largely on the American Society of Heating, Refrigeration, and Air-Conditioning Engineer's (ASHRAE) "Handbook of Fundamentals." (Source: US Department of Energy, 1999a).

Manufacturing Sector. The universe of manufacturing establishments within the 50 States and the District of Columbia. Standard Industrial Classification (SIC) codes used to classify an establishment as a manufacturer are 20 through 39.

Marginal Cost. The cost of producing one additional unit of a product. (Source: US Department of Energy, 1999a).

market clearing price. The price at which supply equals demand. The Day Ahead and Hour Ahead Markets. (Source: California Energy Commission, 1999a.)

marsh. A type of wetland that does not accumulate appreciable peat deposits and is dominated by herbacious vegetation. Marshes may be fresh- or saltwater, tidal or nontidal. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Masonry. Material such as brick, rock, or stone. (Source: US Department of Energy, 1999a).

Masonry Stove. A type of heating appliance similar to a fireplace, but much more efficient and clean burning. They are made of masonry and have long channels through which combustion gases give up their heat to the heavy mass of the stove, which releases the heat slowly into a room. Often called Russian or Finnish fireplaces. (Source: US Department of Energy, 1999a).

mass balance. The application of the principle of the conservation of matter. For example, the mass of a glacier is not destroyed or created; the mass of a glacier and all its constitutive components remains the same despite alterations in their physical states. The mass balance of a glacier is calculated with the input/output relationships of ice, firn, and snow, usually measured in water equivalent. Output includes all ablation processes of surface melting, basal melting, evaporation, wind deflation, calving, and internal melting. Input includes direct precipitation, avalanching, and the growth of superimposed ice. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Mass Burn Facility. A type of municipal solid waste (MSW) incineration facility in which MSW is burned with only minor presorting to remove oversize, hazardous, or explosive materials. Mass burn facilities can be large, with capacities of 3000 tons (2.7 million kg) of MSW per day or more. They can be scaled down to handle the waste from smaller communities, and modular plants with capacities as low as 25 tons (22.7 thousand kg) per day have been built. Mass burn technologies represent over 75% of all the MSW-to-energy facilities constructed in the United States to date. The major components of a mass burn facility include refuse receiving and handling, combustion and steam generation, flue gas cleaning, power generation (optional), condenser cooling water, residue ash hauling and landfilling. (Source: US Department of Energy, 1999a).

Mcf. An abbreviation for one thousand cubic feet of natural gas with a heat content of 1,000,000 Btus, or 10 therms. (Source: US Department of Energy, 1999a).

mean sea level. The average height of the sea surface, based upon hourly observation of the tide height on the open coast or in adjacent waters that have free access to the sea. In the United States, it is defined as the average height of the sea surface for all stages of the tide over a nineteen-year period. Mean sea level, commonly abbreviated as MSL and referred to simply as "sea level", serves as the reference surface for all altitudes in upper atmospheric studies. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Mechanical Systems. Those elements of building used to control the interior climate. (Source: US Department of Energy, 1999a).

Medium Btu Gas. Fuel gas with a heating value of between 200 and 300 Btu per cubic foot. (Source: US Department of Energy, 1999a).

Medium Pressure. For valves and fittings, implies that they are suitable for working pressures between 125 to 175 pounds per square inch. (Source: US Department of Energy, 1999a).

Megawatt (MW). One thousand kilowatts, or 1 million watts; standard measure of electric power plant generating capacity. (Source: US Department of Energy, 1999a).

Megawatt-hour (MWh). One thousand kilowatt-hours or 1 million watt-hours. (Source: US Department of Energy, 1999a).

Mercury Vapor Lamp. A high-intensity discharge lamp that uses mercury as the primary light-producing element. Includes clear, phosphor coated, and self-ballasted lamps. (Source: US Department of Energy, 1999a).

Met. An approximate unit of heat produced by a resting person, equal to about 18.5 Btu per square foot per hour. (Source: US Department of Energy, 1999a).

Metal Halide Lamp. A high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements. These lights have the best Color Rendition Index (CRI) of the High-Intensity Discharge lamps. They can be used for commercial interior lighting or for stadium lights. (Source: US Department of Energy, 1999a).

meter. A device for measuring levels and volumes of a customeržs gas and electricity use. (Source: California Energy Commission, 1999a.)

Methane. A colorless, odorless, tasteless gas composed of one molecule of Carbon and four of hydrogen, which is highly flammable. It is the main constituent of "natural gas" that is formed naturally by methanogenic, anaerobic bacteria or can be manufactured, and which is used as a fuel and for manufacturing chemicals. (Source: US Department of Energy, 1999a).

Methanol (CH3OH; Methyl alcohol or wood alcohol). A clear, colorless, very mobile liquid that is flammable and poisonous; used as a fuel and fuel additive, and to produce chemicals. (Source: US Department of Energy, 1999a).

methyl bromide (CH 3 BR). a compound consisting of carbon, hydrogen, and bromine. Methyl Bromide's chemical formula is CH3BR. An effective pesticide, this compound is used to fumigate soil and many agricultural products. Because it contains bromine, it depletes stratospheric ozone and has an ozone depletion potential of 0.6. Production of methyl bromide will end in the U.S. on 12/31/2000. Much more information is available. (Source: US Environmental Protection Agency, 1999b)

Methyl Chloroform (CH3CCl3). a compound consisting of carbon, hydrogen, and chlorine. Methyl chloroform is used as an industrial solvent. Its ozone depletion potential is 0.11. (Source: US Environmental Protection Agency, 1999b).

Metric Ton (Tonne). A unit of mass equal to 1,000 kilograms or 2,204.6 pounds. (Source: US Department of Energy, 1999a).

Microclimate. The local climate of specific place or habitat, as influenced by landscape features. (Source: US Department of Energy, 1999a).

Micrometer. One millionth of a meter (10-6 m). (Source: US Department of Energy, 1999a).

Midsize car. (See Automobile size classifications)

Mill. A common utility monetary measure equal to one-thousandth of a dollar or a tenth of a cent. (Source: US Department of Energy, 1999a).

millibar. A unit of atmospheric pressure. 1 mb = 100 Pa (pascal). Normal surface pressure is approximately 1013 millibars. (Source: National Weather Service, 1999a.)

Minicompact car. (See Automobile size classifications)

mist. Liquid particles 40 to 500 microns in diameter that are formed by condensation of vapor in air. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Mitigation measures (short- and long-term). Measures for reducing GHG emissions. Long-term measures will generally involve removing barriers to the adoption of climate-friendly, commercially available technologies and making technologies more economically available, while short term measures, such as supply-side efficiency or coals-to-gas conversion projects are also useful in mitigation. (Source: Global Environment Facility, 2000a).

Mixing Valve. A valve operated by a thermostat that can be installed in solar water heating systems to mix cold water with water from the collector loop to maintain a safe water temperature. (Source: US Department of Energy, 1999a).

MMcf. One million cubic feet.

model year. Refers to the "sales" model year; for example, vehicles sold during the period from October 1 to the next September 31 is considered one model year.(Source: US Environmental Protection Agency, 1999a)

modeling. An investigative technique that uses a mathematical or physical representation of a system or theory that accounts for all or some of its known properties. Models are often used to test the effects of changes of system components on the overall performance of the system. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Modified Degree-Day Method. A method used to estimate building heating loads by assuming that heat loss and gain is proportional to the equivalent heat-loss coefficient for the building envelope. (Source: US Department of Energy, 1999a).

Module. The smallest self-contained, environmentally protected structure housing interconnected photovoltaic cells and providing a single dc electrical output; also called a panel. (Source: US Department of Energy, 1999a).

Moisture Content. The water content of a substance (a solid fuel) as measured under specified conditions being the: Dry Basis, which equals the weight of the wet sample minus the weight of a (bone) dry sample divided by the weight of the dry sample times 100 (to get percent); Wet Basis, which is equal to the weight of the wet sample minus the weight of the dry sample divided by the weight of the wet sample times 100. (Source: US Department of Energy, 1999a).

Moisture Control. The process of controlling indoor moisture levels and condensation. (Source: US Department of Energy, 1999a).

Monolithic. Fabricated as a single structure. (Source: US Department of Energy, 1999a).

Monoculture. The planting, cultivation, and harvesting of a single species of crop in a specified area. (Source: US Department of Energy, 1999a).

monsoon. A name for seasonal winds, first applied to the winds over the Arabian Sea that blow for six months from the northeast and for six months from the southwest. The term has been extended to similar winds in other parts of the world (i.e., the prevailing west to northwest winds of summer in Europe have been called the European monsoon). The primary cause for these seasonal winds is the much greater annual variation of temperature over large land areas compared with neighboring ocean surfaces, causing an excess of pressure over the continents in winter and a deficit in summer, but other factors, such as topography of the land, also have an effect. The monsoons are strongest in the southern and eastern sides of Asia, but also occur along the coasts of tropical regions wherever the planetary circulation is not strong enough to inhibit them. The monsoon climate can be described as a long winter-spring dry season, which includes a cold season followed by a short hot season just preceding the rains; a summer and early autumn rainy season, which is generally very wet but may vary greatly from year to year; and a secondary warming immediately after the rainy season. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Montreal Protocol On Substances That Deplete The Ozone Layer. the international treaty governing the protection of stratospheric ozone. The Montreal Protocol on Substances That Deplete the Ozone Layer and its amendments control the phaseout of ODS production and use. Under the MP, several international organizations report on the science of ozone depletion, implement projects to help move away from ODS, and provide a forum for policy discussions. In addition, the Multilateral Fund provides resources to developing nations to promote the transition to ozone-safe technologies. The full text of the MP is available online and it is part of the OzonAction Information Clearinghouse database. (Source: US Environmental Protection Agency, 1999b).

Motor. A machine supplied with external energy that is converted into force and/or motion. (Source: US Department of Energy, 1999a).

motor gasoline. A complex mixture of relatively volatile hydrocarbons, with or without small quantities of additives, obtained by blending appropriate refinery streams to form a fuel suit-able for use in spark-ignition engines. Motor gasoline includes both leaded and unleaded grades of finished gasoline, blending components, and gasohol.(Source: US Environmental Protection Agency, 1999a)

Motor Speed. The number of revolutions that the motor turns in a given time period (i.e. revolutions per minute, rpm). (Source: US Department of Energy, 1999a).

Movable Insulation. A device that reduces heat loss at night and during cloudy periods and heat gain during the day in warm weather. A movable insulator could be an insulative shade, shutter panel, or curtain. (Source: US Department of Energy, 1999a).

MTBE. Methyl Tertiary Butyl Ether (MTBE) is an ether compound used as a gasoline blending component to raise the oxygen content of gasoline. MTBE is made by combining isobutylene (from various refining and chemical processes) and methanol (usually made from natural gas). (Source: US Department of Energy, 1999a).

Multi-Zone System. A building heating, ventilation, and/or air conditioning system that distributes conditioned air to individual zones or rooms. (Source: US Department of Energy, 1999a).

Multilateral. Referring to actions or activities involving two or more nations. (Source: Global Environment Facility, 2000a).

Municipal Solid Waste (MSW). Waste material from households and businesses in a community that is not regulated as hazardous. (Source: US Department of Energy, 1999a).

Municipal Waste. As defined in the Energy Security Act (P.L. 96-294; 1980) as "any organic matter, including sewage, sewage sludge, and industrial or commercial waste, and mixtures of such matter and inorganic refuse from any publicly or privately operated municipal waste collection or similar disposal system, or from similar waste flows (other than such flows which constitute agricultural wastes or residues, or wood wastes or residues from wood harvesting activities or production of forest products)." (Source: US Department of Energy, 1999a).

Municipal Waste to Energy Project (or Plant). A facility that produces fuel or energy from municipal solid waste. (Source: US Department of Energy, 1999a).


N

Name Plate. A metal tag attached to a machine or appliance that contains information such as brand name, serial number, voltage, power ratings under specified conditions, and other manufacturer supplied data. (Source: US Department of Energy, 1999a).

Nanometer. a distance of one billionth of a meter. The nanometer, or nm, is a common unit used to describe wavelengths of light or other electromagnetic radiation such as UV. For example, green light has wavelengths of about 500-550 nm, while violet light has wavelengths of about 400-450 nm. One billionth is a tiny number. One foot is about one billionth the distance of 48 round-trips between Los Angeles and Washington, DC. (Source: US Environmental Protection Agency, 1999b).

Natural Cooling. Space cooling achieved by shading, natural (unassisted, as opposed to forced) ventilation, conduction control, radiation, and evaporation; also called passive cooling. (Source: US Department of Energy, 1999a).

Natural Draft. Draft that is caused by temperature differences in the air. (Source: US Department of Energy, 1999a).

Natural Gas. A hydrocarbon gas obtained from underground sources, often in association with petroleum and coal deposits. It generally contains a high percentage of methane, varying amounts of ethane, and inert gases; used as a heating fuel. (Source: US Department of Energy, 1999a).

Natural Gas Steam Reforming Production. A two step process where in the first step natural gas is exposed to a high-temperature steam to produce hydrogen, carbon monoxide, and carbon dioxide. The second step is to convert the carbon monoxide with steam to produce additional hydrogen and carbon dioxide. (Source: US Department of Energy, 1999a).

Natural Ventilation. Ventilation that is created by the differences in the distribution of air pressures around a building. Air moves from areas of high pressure to areas of low pressure with gravity and wind pressure affecting the airflow. The placement and control of doors and windows alters natural ventilation patterns. (Source: US Department of Energy, 1999a).

negative feedback. An interaction that reduces or dampens the response of the system in which it is incorporated. See feedback mechanisms. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Net Energy Production (or Balance). The amount of useful energy produced by a system less the amount of energy required to produce the fuel. (Source: US Department of Energy, 1999a).

Net Generation. Equal to gross generation less electricity consumption of a power plant. (Source: US Department of Energy, 1999a).

Net (Lower) Heating Value (NHV). The potential energy available in a fuel as received, taking into account the energy loss in evaporating and superheating the water in the fuel. Equal to the higher heating value minus 1050W where W is the weight of the water formed from the hydrogen in the fuel, and 1050 is the latent heat of vaporization of water, in Btu, at 77 degrees Fahrenheit. (Source: US Department of Energy, 1999a).

Net Metering. The practice of using a single meter to measure consumption and generation of electricity by a small generation facility (such as a house with a wind or solar photovoltaic system). The net energy produced or consumed is purchased from or sold to the generator, respectively, at the same price. (Source: US Department of Energy, 1999a).

Net Present Value. The value of a personal portfolio, product, or investment after depreciation and interest on debt capital are subtracted from operating income. It can also be thought of as the equivalent worth of all cash flows relative to a base point called the present. (Source: US Department of Energy, 1999a).

net primary production. The part of the gross primary production that remains stored in the producer organism (primarily green plants) after deducting the amount used during the process of respiration. Abbreviated NPP. (Source: Carbon Dioxide Information Analysis Center, 1990a).

Net Summer Capability. The steady hourly output, which generating equipment is expected to supply to system load exclusive of auxiliary power, as demonstrated by tests at the time of summer peak demand. (Source: US Energy Information Administration, 1999b)

Net Winter Capability. The steady hourly output which generating equipment is expected to supply to system load exclusive of auxiliary power, as demonstrated by tests at the time of winter peak demand. (Source: US Energy Information Administration, 1999b)

NGV (natural gas vehicle).. vehicles that are powered by compressed or liquefied natural gas. (Source: California Energy Commission, 1999a.)

nitrogen cycle. Cyclic movement of nitrogen in different chemical forms from the environment, to organisms, and then back to the environment.(Source: US Environmental Protection Agency, 1999a)

Nitrogen Dioxide. This compound of nitrogen and oxygen is formed by the oxidation of nitric oxide (NO) which is produced by the combustion of solid fuels. (Source: US Department of Energy, 1999a).

nitrogen fixation. Conversion of atmospheric nitrogen gas into forms useful to plants and other organisms by lightning, bacteria, and blue-green algae; it is part of the nitrogen cycle.(Source: US Environmental Protection Agency, 1999a)

nitrogen oxides (NO x ). Gases consisting of one molecule of nitrogen and varying numbers of oxygen molecules. Nitrogen oxides are produced, for example, by the combustion of fossil fuels in vehicles and electric power plants. In the atmosphere, nitrogen oxides can contribute to formation of photo-chemical ozone (smog), impair visibility, and have health consequences; they are considered pollutants.(Source: US Environmental Protection Agency, 1999a)

Nominal Capacity. The approximate energy producing capacity of a power plant, under specified conditions, usually during periods of highest load. (Source: US Department of Energy, 1999a).

Nominal Price. The price paid for goods or services at the time of a transaction; a price that has not been adjusted to account for inflation. (Source: US Department of Energy, 1999a).

Nocturnal Cooling. The effect of cooling by the radiation of heat from a building to the night sky. (Source: US Department of Energy, 1999a).

non-firm energy. Electricity that is not required to be delivered or to be taken under the terms of an electric purchase contract. (Source: California Energy Commission, 1999a.)

Non-governmental Organization (NGO). Any organization that is not governmental or affiliated with the government, but more generally referring to the many independent organizations in civil society with interest in environment and development activities. (Source: Global Environment Facility, 2000a).

non-point source. Large land area such as crop fields and urban areas that discharge pollutant into surface and underground water over a large area. See point source.(Source: US Environmental Protection Agency, 1999a)

nonbiodegradable. Substance that cannot be broken down in the environment by natural processes. See biodegradable.(Source: US Environmental Protection Agency, 1999a)

nonlinearities. Occur when changes in one variable cause a more than proportionate impact on another variable.(Source: US Environmental Protection Agency, 1999a)

Nonrenewable Fuels. Fuels that cannot be easily made or "renewed," such as oil, natural gas, and coal. (Source: US Department of Energy, 1999a).

Non-Utility Generator/Power Producer. A class of power generator that is not a regulated utility and that has generating plants for the purpose of supplying electric power required in the conduct of their industrial and commercial operations. (Source: US Department of Energy, 1999a).

Normal Recovery Capacity. A characteristic applied to domestic water heaters that is the amount of gallons raised 100 degrees Fahrenheit per hour (or minute) under a specified thermal efficiency. (Source: US Department of Energy, 1999a).

NOx. Oxides of nitrogen that are a chief component of air pollution that can be produced by the burning of fossil fuels. Also called nitrogen oxides. (Source: California Energy Commission, 1999a.)

Nuclear Energy. Energy that comes from splitting atoms of radioactive materials, such as uranium, and which produces radioactive wastes. (Source: US Department of Energy, 1999a).

NUG.A non-utility generator. A generation facility owned and operated by an entity who is not defined as a utility in that jurisdictional area. (Source: California Energy Commission, 1999a.)

nutrient. Any substance assimilated by living things that promotes growth. (Source: Carbon Dioxide Information Analysis Center, 1990a).