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Accreditation: Procedure by which an authoritative body gives formal recognition that a body is impartial and technically competent to carry out specific tasks such as certification, tests, specific types of tests etc. Note: Accreditation is awarded following successful assessment and is followed by appropriate surveillance.

Acid Rain: Also called "acid precipitation" or "acid deposition," acid rain is precipitation containing harmful amounts of nitric and sulfuric acids formed primarily by nitrogen oxides and sulfur oxides released into the atmosphere when fossil fuels are burned. It can be wet precipitation (rain, snow, or fog) or dry precipitation (absorbed gaseous and particulate matter, aerosol particles, or dust). Acid rain has a pH below 5.6. Normal rain has a pH of about 5.6, which is slightly acidic. (The pH value is a measure of acidity or alkalinity, ranging from 0 to 14. A pH measurement of 7 is regarded as neutral. Measurements below 7 indicate increased acidity, and those above 7 indicate increased alkalinity.)

Activation Energy: Activation energy of a reaction is the amount of energy needed to start the reaction.

Active Heating System: A solar water or space-heating system that moves heated air or water using pumps or fans.

Air-Conditioning - Cooling and dehumidifying the air in a building by a refrigeration unit by a refrigeration unit powered by electricity or natural gas. This definition excludes fans, blowers, or evaporative cooling systems (swamp coolers) that are not connected to a refrigeration unit.

Alternating Current: An electric current that reverses its direction at regularly recurring intervals, usually 50 or 60 times per second.

Alternative Fuel - A popular term for "non-conventional" transportation fuels made from natural gas (propane, compressed natural gas, methanol, etc.) or biomass materials (ethanol, methanol).

Alternative-Fuel Vehicle (AFV) - A vehicle designed to operate on an alternative fuel (e.g., compressed natural gas, methane blend, electricity). The vehicle could be either a vehicle designed to operate exclusively on alternative fuel or a vehicle designed to operate on alternative fuel and/or a traditional fuel.

Amorphous Silicon: An alloy of silica and hydrogen, with a disordered, non-crystalline internal atomic arrangement, that can be deposited in thin-layers (a few micrometers in thickness) by a number of deposition methods to produce thin-film photovoltaic cells on glass, metal, or plastic substrates.

Ampere - A unit of measure for an electrical current; the amount of current that flows in a circuit at an electromotive force of one Volt and at a resistance of one Ohm. Abbreviated as amp.

Annualized Growth Rates: Calculated as follows:(xn / x1) *1/n where x is the value under consideration and n is the number of periods and * means to multiply.

Avoided Costs: The incremental costs of energy and/or capacity, except for the purchase from a qualifying facility, a utility would incur itself in the generation of the energy or its purchase from another source.

Baghouse: A woven or felted fabric bag-like device that lets gas through but removes suspended particles.

Barrel: 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.

Base:The structure below the generator of a wind turbine that supports the turbine, houses the meters and wires, and keeps the turbine high above the ground level to protect the surrounding area and people from the force of the blades.Also, to get the turbine above the surrounding buildings which could otherwise block the wind.

Battery: An energy storage device made up of one or more electrolyte cells.

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.

Biofuels - Liquid fuels and blending components produced from biomass (plant) feedstocks, used primarily for transportation.

Bioreactor - A landfill where the waste actively decomposes rather being simply buried in a "dry tomb."

Boiler - a tank in which water is heated to produce either hot water or steam that is circulated for the purpose of heating and power.

Biomass -- Wood waste, agricultural wastes, methane gases from landfills, and crops grown specifically for energy production.

Biota: The flora and fauna of a region.

Black Liquor: A byproduct of the paper production process that can be used as a source of energy.

Blades: Usually flat ojbects connected to a center shaft that converts the push of the wind into a circular motion in a wind turbine.

Bleached Board: A wood product used for printed and graphically enhanced card stock, books, and packaging such as food cartons, microwave trays, beverages, candy, cosmetics, pharmaceuticals, and consumer electronic items. Pollutants, such as dioxins and furans, can result from processes that use chlorine in the manufacture of bleached board.

Brake (WT): Device capable of reducing the rotor speed or stopping rotation

Brine: A highly saline solution. A solution containing appreciable amounts of sodium chloride and other salts.

British Thermal Unit (BTU): A unit of energy; 1055 Joules is equal to 1 BTU.

Busbar Cost: The cost per kilowatthour to produce electricity, including the cost of capital, debt service, operation and maintenance, and fuel. The power plant "bus" or "busbar" is that point beyond the generator but prior to the voltage transformation point in the plant switchyard.

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.

Capacity: The maximum power that a machine such as an electrical generator or a system such as a transmission line can safely produce or handle.

Capacity Factor: The amount of energy a facility generates in one year divided by the total amount it could generate if it ran at full capacity:A capacity factor of one implies that the system ran at full capacity the entire year; a typical wind farm will operate at 0.25 capacity factor, or 25%.

Capacity, Gross: The full-load continuous rating of a generator, prime mover, or other electric equipment under specified conditions as designated by the manufacturer. It is usually indicated on a nameplate attached to the equipment.

Capital Cost: The cost of field development and plant construction and the equipment required for the generation of electricity.

Carbon Dioxide: A colorless, odorless noncombustible gas with the formula CO2 that is present in the atmosphere. It is formed by the combustion of carbon and carbon compounds (such as fossil fuels and biomass) and by respiration, which is a slow combustion in animals and plants, and by the gradual oxidation of organic matter in the soil.

Cast Silicon: Crystalline silicon obtained by pouring pure molten silicon into a vertical mold and adjusting the temperature gradient along the mold volume during cooling to obtain slow, vertically-advancing crystallization of the silicon. The polycrystalline ingot thus formed is composed of large, relatively parallel, interlocking crystals. The cast ingots are sawed into wafers for further fabrication into photovoltaic cells. Cast-silicon wafers and ribbon-silicon sheets fabricated into cells are usually referred to as polycrystalline photovoltaic cells.

Certificate holder: Entity holding a provisional certificate after the certificate is issued.

Note: This entity may not be the original applicant but nevertheless is responsible for maintenance of the certificate

Certification Body: Body that conducts provisional cerification of conformity

Certification system: System that has specific rules for procedure and management to carry out certification of conformity

Chain Reaction: A self-sustaining nuclear reaction which takes place during fission. A fissionable substance (i.e., uranium) absorbs a neutron and divides, releasing additional neutrons that are absorbed by other fissionable nuclei, releasing still more neutrons.

Chemical Energy: Energy stored in a substance and released during a chemical reaction such as burning wood, coal, or oil.

Circuit(s): A conductor or a system of conductors through which electric current flows.

Climate Change (Greenhouse Effect): The increasing mean global surface temperature of the Earth caused by gases in the atmosphere (including carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbons. The greenhouse effect allows solar radiation to penetrate the Earth’s atmosphere but absorbs the infrared radiation returning to space.

Coal: A fossil fuel formed by the breakdown of vegetable material trapped underground without access to air.

Coal-Fired Power Plant: A power plant that uses coal as the fuel to generate electricity.

Cogeneration: The production of electrical energy and another form of useful energy (such as heat or steam) through the sequential use of energy.

Collector Field: The area where many solar collectors are situated in a solar power plant.

Combustion: Chemical oxidation accompanied by the generation of light and heat.

Combined Cycle: An electric generating technology in which electricity is produced from otherwise lost waste heat exiting from one or more gas (combustion) turbines. The exiting heat is routed to a conventional boiler or to a heat recovery steam generator for utilization by a steam turbine in the production of electricity. Such designs increase the efficiency of the electric generating unit.

Concentrator: A reflective or refractive device that focuses incident insolation onto an area smaller than the reflective or refractive surface, resulting in increased insolation at the point of focus.

Control system (WT): Subsystem that receives information about the condition of the WT and/or its environment and adjusts the turbine in order to maintain it within its operating limits

Convection: Motion in a fluid or plastic material due to some parts being buoyant because of their higher temperature. Convection is a means of transferring heat through mass flow rather than through simple thermal conduction.

Convert: To change from one form to another. In this curriculum, usually wind energy into electrical energy or solor energy into electrical energy or from electrical energy into light energy.

Cooperative: A form of utility in which all users own shares. Cooperatives are common in rural areas that are expensive to serve because of the long distances between users. Frequently, the government contributes in various ways to rural cooperatives to reduce costs to individual owner/users.

Cull Wood: Wood logs, chips, or wood products that are burned.

Cut-in wind speed (Vin) : Lowest mean wind speed at hub-height at which the WT starts to produce power

Cut-out wind speed (Vout): Highest mean wind speed at hub-height at which the WT is designed to produce power

Cyclones: Cyclonic storms in sea gradually reduce in intensity as they approach coastal regions. The zone of influence generally extends up to 60 kms in land.

Note : This effect of reduction on land is already reflected in basic wind speeds as specified by IS 875

Deregulation: The process of removing restrictive regulations on previously regulated companies.

Design limits: Maximum or minimum values used in a design

Diffuse Radiation: Scattered radiation from the sun that comes from all portions of the sky.

Dioxins: A classification of chlorine-containing compounds that are considered extremely toxic carcinogenic agents. Toxic effects include anorexia, hepatotoxicity, chloracne, vascular lesions, and gastric ulcers. Dioxins are byproducts in the manufacture of some chemicals. Causes of dioxin production in combustion begin with chlorine compounds in fuel, inadequate supply of combustion air, too low refractory temperatures, and improper mixing of fuel and air.

Deforestation: The net removal of trees from forested land.

Dormant failure (also known as latent fault): Failure of a component or system which remains undetected during normal operation

Diesel Engine: Diesel engines are internal combustion engines that burn diesel oil rather than gasoline.

Diesel Fuel: A fuel composed of distillates obtained in petroleum refining operation or blends of such distillates with residual oil used in motor vehicles. The boiling point and specific gravity are higher for diesel fuels than for gasoline.

Direct Current: An electric current that flows in a constant direction. The magnitude of the current does not vary or has a slight variation.

Drilling: The act of boring a hole (1) to determine whether minerals are present in commercially recoverable quantities and (2) to accomplish production of the minerals (including drilling to inject fluids). There are three types of drilling : exploratory - drilling to locate probable mineral deposits or to establish the nature of geological structures; such wells may not be capable of production if minerals are discovered; developmental - drilling to delineate the boundaries of a known mineral deposit to enhance the productive capacity of the producing mineral property; and directional - drilling that is deliberately made to depart significantly from the vertical.

Dynamo: A device that changes mechanical energy into electrical energy.

Electrical Energy: The energy associated with electric charges and their movements.

Electrical Light: Light that has been produced by electricity, the source is usually batteries or over wires from a generator.

Electricity: A flow of electrons (very tiny particles) that is used to power lights, motors, tools, and many other devices. We get electricity from batteries or over wires from generators.

Electricity Generation: The process of producing electric energy or the amount of electric energy produced by transforming other forms of energy, commonly expressed in kilowatthours (kWh) or megawatthours (MWh).

Electric Motor: A device that takes electrical energy and converts it into mechanical energy to turn a shaft.

Electric Power: The amount of energy produced per second. The power produced by an electric current.

Electrical power network: Particular installations, substations, lines or cables for the transmission and distribution of electricity

Electromagnetic: Having to do with magnetism produced by an electric current.

Electromagnetic Energy: Energy that travels in waves, such as ultra-violet radiation. It can be thought of as a combination of electric and magnetic energy.

Electromagnetic Waves: Radiation that consists of traveling waves of electric and magnetic disturbances. X-rays, light rays and radio waves are among the many kinds of electromagnetic waves.

Electron:- A subatomic particle with a negative electric charge. Electrons form part of an atom and move around its nucleus.

Electric Utility Restructuring: With some notable exceptions, the electric power industry historically has been composed primarily of investor-owned utilities. These utilities have been predominantly vertically integrated monopolies (combining electricity generation, transmission, and distribution), whose prices have been regulated by State and Federal government agencies. Restructuring the industry entails the introduction of competition into at least the generation phase of electricity production, with a corresponding decrease in regulatory control. Restructuring may also modify or eliminate other traditional aspects of investor-owned utilities, including their exclusive franchise to serve a given geographical area, assured rates of return, and vertical integration of the production process.

Electrostatic Precipitator: A number of vertical, parallel metal plates utilizing the mutual attraction of opposite electric charges to remove dust or ash particles or liquid droplets suspended in a gas.

Emergency shutdown (WT): Rapid shutdown of the WT triggered by a protection system or by manual intervention

Emission: The release or discharge of a substance into the environment; generally refers to the release of gases or particulates into the air.

Emissions Trading: With an emissions trading system, a regulatory agency specifies an overall level of pollution that will be tolerated (a cap) and then uses allowances to develop a market to allocate the pollution among sources of pollution under the cap. Emissions permits or allowances become the currency of the market, as pollution sources are free to buy, sell, or otherwise trade permits based on their own marginal costs of control and the price of the permits. In no case can total emissions exceed the cap.

Energy: The capacity for doing work, either in motion (kinetic) or stored up (potential). That which can cause or causes motion.

Energy Consumption: The use of energy as a source of heat or power or as a raw material input to a manufacturing process.

Environmental conditions: Characteristics of the environment (altitude, temperature, humidity, etc.) which may affect the WT behaviour

Ethyl Tertiary Butyl Ether (ETBE): A colorless, flammable, oxygenated hydrocarbon ((CH3)3COC2H5) blend stock formed by the catalytic etherification of isobutylene with ethanol.

Evaluation for conformity: Systematic examination of the extent to which a product, process or service fulfils specified requirements

Evacuated Tube: In a solar thermal collector, an absorber tube, which is contained in an evacuated glass cylinder, through which collector fluids flows.

Exempt: Wholesale Generator (EWG): A non-utility electricity generator that is not a qualifying facility under the Public Utility Regulatory Policies Act of 1978.

External conditions (WT): Factors affecting operation of a WT, including the wind regime, the electrical network conditions, and other climatic factors (temperature, snow, ice, etc.)

Extreme wind speed: Highest average wind speed, averaged over t seconds, that is likely to be experienced within a specified time period of N years (”recurrence period”: N years)

Note: In this standard recurrence periods of N = 50 years and N = 1 year and averaging time intervals of t=3 sec. and t=10 min are used. In popular language, the less precise term ”survival wind speed” is often used. In this standard, however, the WT is designed using extreme wind speeds for design load cases

Externalities: Benefits or costs, generated as a byproduct of an economic activity, that do not accrue to the parties involved in the activity. Environmental externalities are benefits or costs that manifest themselves through changes in the physical or biological environment.

Fail-safe: Design property of an item which prevents its failures from resulting in critical faults

Filament: The fine metal wire in a light bulb that glows when heated by an electric current.

Final evaluation report: Report containing the results of conformity evaluations relating to Provisional Type Certification. It is the basis for the decision to issue the Provisional Type Certificate

Fission: 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.

Flat-Plate Solar Connector: A device designed to capture the suns energy and produce low temperature heat energy. They are commonly used as collectors in solar heating systems.

Flat Plate Pumped: A medium-temperature solar thermal collector that typically consists of a metal frame, glazing, absorbers (usually metal), and insulation and that uses a pump liquid as the heat-transfer medium: predominant use is in water heating applications.

Flow: To move or run smoothly with unbroken continuity, as in the manner characteristic of a fluid.

Flow Control: The laws, regulations, and economic incentives or disincentives used by waste managers to direct waste generated in a specific geographic area to a designated landfill, recycling, or waste-to-energy facility.

Force: Something which changes the state of rest or motion of something.

Forest Residues: Unused wood in the forest including logging residues, cull trees, dead trees, and annual mortality.

Fossil Fuels: Fuels (coal, oil, natural gas, etc.) that result from the compression of ancient plant and animal life formed over millions of years.

Fuel: Any material that can be burned to make energy.

Fuel Cycle: The entire set of stages involved in the utilization of fuel, including extraction, transformation, transportation, and combustion.

Fuel Cells: One or more cells capable of generating an electrical current by converting the chemical energy of a fuel directly into electrical energy. Fuel cells differ from conventional electrical cells in that the active materials such as fuel and oxygen are not contained within the cell but are supplied from outside.

Fuel Oil : An oil that is used for fuel and that usually ignites at a higher temperature than kerosene.

Fuel wood: Wood and wood products, possibly including coppices, scrubs, branches, etc., bought or gathered, and used by direct combustion.

Furnace: An enclosed structure in which heat is produced for the purpose of heating a house or a building.

Fusion: When the nuclei of atoms are combined or "fused" together. The sun combines the nuclei of hydrogen atoms into helium atoms in a process called fusion. Energy from the nuclei of atoms, called "nuclear energy" is released from fusion.

Fumarole: A vent from which steam or gases issue; a geyser or spring that emits gases.

Furans: A class of organic heterocyclic compounds regulated by the U.S. Environmental Protection Agency because of their toxic characteristics. Among other sources, furans can be produced as a byproduct in some pine tar distillation processes. Some derivatives of furans, such as furfuryl alcohol, tetrahydrofurfuryl alcohol, and tetrahydrofuran, are commercially important. Furans can be generated by the same combustion problems described for dioxins.

Gallon: A measure of volume equal to 4 quarts (231 cubic inches). One barrel equals 42 gallons.

Gas: (1) A non-solid, non-liquid (as hydrogen or air) substance that has no fixed shape and tends to expand without limit. (2) A state of matter in which the matter concerned occupies the whole of its container irrespective of its quantity. Includes natural gas, coke-oven gas, blast furnace gas, and refinery gas.

Gasoline: A complex mixture of relatively volatile hydrocarbons with or without small quantities of additives, blended to form a fuel suitable for use in spark-ignition engines.

Gas To Liquids (GTL): A process that combines the carbon and hydrogen elements in natural gas molecules to make synthetic liquid petroleum products, such as diesel fuel.

Gas Turbine Plant: A plant in which the prime mover is a gas turbine. A gas turbine consists typically of an axial-flow air compressor and one or more combustion chambers where liquid or gaseous fuel is burned and the hot gases are passed to the turbine and where the hot gases expand drive the generator and are then used to run the compressor.

Generator: A device that turns mechanical energy into electrical energy. The mechanical energy is sometimes provided by an engine or turbine.

Generation (Electricity): The process of producing electric energy from other forms of energy; also, the amount of electric energy produced, expressed in watt hours (Wh).

Generating Capacity: The amount of electrical power a power plant can produce.

Geopressured: A type of geothermal resource occurring in deep basins in which the fluid is under very high pressure.

Geothermal Energy: As used at electric utilities, hot water or steam extracted from geothermal reservoirs in the Earth’s crust that is supplied to steam turbines at electric utilities that drive generators to produce electricity.

Geopressured Geothermal: Type of geothermal resource occurring in deep basins in which fluid is under pressure.

Geothermal Plant: A plant in which a turbine is driven either from hot water or by natural steam that derives its energy from heat found in rocks or fluids at various depths beneath the surface of the earth. The fluids are extracted by drilling and/or pumping.

Geyser: A special type of thermal spring that periodically ejects water with great force.

Giga: One billion.

GIS: Geographic Information System.

Global Warming: An effect caused by the greenhouse effect characterized by a slight, continuous rise in the average temperature throughout the earth. This would cause extreme changes in climate, polar ice melt, and ecological havoc.

Gravity: The natural force of attraction of the mass of a heavenly body (as the earth) for bodies at or near its surface.

Greenhouse Effect: The increasing mean global surface temperature of the Earth caused by gases in the atmosphere (including carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbons). The greenhouse effect allows solar radiation to penetrate the Earth’s atmosphere but absorbs the infrared radiation returning to space.

Green Liquor: The raw mill effluent that results from the pulping and/or bleaching process in pulp and paper mills. Black liquor can be recovered from green liquor by evaporation and membrane processing.

Green Pricing: In the case of renewable electricity, green pricing represents a market solution to the various problems associated with regulatory valuation of the non-market benefits of renewables. Green pricing programs allow electricity customers to express their willingness to pay for renewable energy development through direct payments on their monthly utility bills.

Grid: The layout of an electrical distribution system.

Grid Availability: Grid availability in simple terms means the availability of electrical transmission system of a utility for carrying the energy generated by a turbine or a group of turbines. It represents as a percentage factor that needs to be applied to the gross energy to account the loss of energy associated with the down time of the grid connection.

Groundwater: Water occurring in the subsurface zone where all spaces are filled with water under pressure greater than that of the atmosphere.

Gust: Temporary change in the wind speed

Note: A gust may be characterised by its rise –time, its magnitude and its duration.

Heat Exchanger: Any device that transfers heat from one fluid (liquid or gas) to another or to the environment.

Heliostat: Flat sun-tracking mirrors used to reflect and concentrate the suns' energy onto a central receiver tower.

High-Temperature Collector: A solar thermal collector designed to operate at a temperature of 180 degrees Fahrenheit or higher.

Horizontal axis WT: WT whose rotor axis is substantially parallel to the wind flow

Horsepower: A unit for measuring the rate of work (or power) equivalent to 33,000 foot-pounds per minute or 746 watts.

Hot Dry Rock: Heat energy residing in impermeable, crystalline rock. Hydraulic fracturing may be used to create permeability to enable circulation of water and removal of the heat.

Hub (WT): Fixture for attaching the blades or blade assembly to the rotor shaft

Hub-height (WT): Height of the centre of the swept area of the WT rotor above the terrain surface

Hydroelectric Power Plant: A power plant that uses moving water to power a turbine generator to produce electricity.

Hydraulic Fracturing: Fracturing of rock at depth with fluid pressure. Hydraulic fracturing at depth may be accomplished by pumping water into a well at very high pressures. Under natural conditions, vapor pressure may rise high enough to cause fracturing in a process known as hydrothermal brecciation.

Hydrogen: A colorless, odorless, highly flammable gaseous element. It is the lightest of all gases and the most abundant element in the universe, occurring chiefly in combination with oxygen in water and also in acids, bases, alcohols, petroleum, and other hydrocarbons.

Hydropower: Energy that comes from moving water.

Independent Power Producer (IPP): A wholesale electricity producer (other than a qualifying facility under the Public Utility Regulatory Policies Act of 1978), that is unaffiliated with franchised utilities in the area in which the IPP is selling power and that lacks significant marketing power. Unlike traditional utilities, IPPs do not possess transmission facilities that are essential to their customers and do not sell power in any retail service territory where they have a franchise.

Induction: The process of producing an electrical or magnetic effect through the influence of a nearby magnet, electric current, or electrically charged body.

Inertia: A property of matter by which it remains at rest or in uniform motion in the same straight line unless acted upon by some outside force.

Insolation: Amount of solar energy reaching a surface per unit of time.

Inspection: Systematic examination of the extent to which a product, process or service fulfils specified requirements by means of measuring, observing, testing or gauging the relevant characteristics

Installation: Process that encompasses on site fabrication, assembly, erection and commissioning

Internal Collector Storage (ICS): A solar thermal collector in which incident solar radiation is absorbed by the storage medium.

Investor: owned utility (IOU): A utility with stock-based ownership.

Joule: A standard international unit of energy; 1055 Joules is equal to 1 BTU.

Kerosene: A thick oil obtained from petroleum and used as a fuel and solvent.

Kilowatt-hour (kWh): A unit of energy equal to one kW applied for one hour; running a one kW hair dryer for one hour would dissipate one kWh of electrical energy as heat.

Kilowatt (kW): One thousand watts of electricity (See Watt).

Kilowatthour (kWh): One thousand watt hours.

Kinetic Energy: Energy possessed by virtue of an object's motion.

Kinetic Theory of Gases: The theory that physical properties of a gas are due to the rapid motion in a straight line of its molecules, to their impacts against each other and the walls of the container, and to weak attraction forces between the molecules.

Levelized Cost: The present value of the total cost of building and operating a generating plant over its economic life, converted to equal annual payments. Costs are levelized in real dollars (i.e., adjusted to remove the impact of inflation).

Light: A form of radiation that is visible to the human eye enabling sight. The light source is called radiant and is caused by one form of energy converted into radiation or radiant light,

Liquid Collector: A medium-temperature solar thermal collector, employed predominantly in water heating, which uses pumped liquid as the heat-transfer medium.

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.

Low-Temperature Collectors: Metallic or nonmetallic solar thermal collectors that generally operate at temperatures below 110 degrees Fahrenheit and use pumped liquid or air as the heat transfer medium. They usually contain no glazing and no insulation, and they are often made of plastic or rubber, although some are made of metal.

Machine Availability: This factor defines the expected average turbine availability of the wind farm over the life of the project. It represents, as a percentage, the facto which needs to be applied to the gross energy to account for the loss of energy associated with the amount of time the turbines are unavailable to produce electricity.

Magma: Naturally occurring molten rock, generated within the earth and capable of intrusion and extrusion, from which igneous rocks are thought to have been derived through solidification and related processes. It may or may not contain suspended solids (such as crystals and rock fragments) and/or gas phases.

Magnet: Any piece of iron, steel, etc., that has the property of attracting iron or steel.

Manufacture: Process that encompassess fabrication and assembly in a workshop

Manufacturer: Entity manufacturing the WT or, where relevant, main components of the WT.

Marginal Cost: The change in cost associated with a unit change in quantity supplied or produced.

Mass Burner: A relatively large one-chamber combustion system used to incinerate municipal solid waste under conditions of excess air; it is built on site and consumes fuel without prior processing or sorting.

Maximum power (WT): Highest level of net electrical power delivered by a WT in normal operation.

Mean wind speed: Statistical mean of the instantaneous value of the wind speed averaged over a given time period which can vary from a few seconds to many years.

Mechanical Energy: The energy of motion used to perform work.

Mechanical Power: The power produced by motion.

Medium-Temperature Collectors: Solar thermal collectors designed to operate in the temperature range of 140 degrees to 180 degrees Fahrenheit, but that can also operate at a temperature as low as 110 degrees Fahrenheit. The collector typically consists of a metal frame, metal absorption panels with integral flow channels (attached tubing for liquid collectors or integral ducting for air collectors), and glazing and insulation on the sides and back.

Megajoule (MJ): One million Joules.

Megawatt (MW): One Million Watts; a modern coal plant will have a capacity of about 1,000 MW.

Mercaptan: An organic chemical compound that has a sulfur like odor that is added to natural gas before distribution to the consumer, to give it a distinct, unpleasant odor (smells like rotten eggs). This serves as a safety device by allowing it to be detected in the atmosphere, in cases where leaks occur.

Merchant Facilities: High-risk, high-profit facilities that operate, at least partially, at the whims of the market, as opposed to those facilities that are constructed with close cooperation of municipalities and have significant amounts of waste supply guaranteed.

Methane: The most common gas formed in coal mines; a major component of natural gas.

Methyl Tertiary Butyl Ether (MTBE): A color- less, flammable, liquid oxygenated hydrocarbon ((CH3)3COCH3) that contains 18.15 percent oxygen and has a boiling point of 55.2 degrees Celsius. It is a fuel oxygenate produced by reacting methanol with isobutylene.

Miles Per Gallon (MPG): A measure of vehicle fuel efficiency. MPG is computed as the ratio of the total number of miles traveled by a vehicle to the total number of gallons consumed.

Mobile Home: A trailer that is used as a permanent dwelling.

Modular Burner: A relatively small two-chamber combustion system used to incinerate municipal solid waste without prior processing or sorting; usually fabricated at a factory and delivered to the incineration site.

Molecule: Particles that normally consist of two or more atoms joined together. An example is a water molecule that is made up of two hydrogen atoms and one oxygen atom.

Multifamily Dwellings: Apartment building and condominiums.

Municipal Solid Waste (MSW): Urban refuse collected for landfilling and including paper, organic matter, metals, plastic, etc., but not certain agricultural or industrial wastes.

Municipal utility or Muni: A utility owned by a city. Generally, surpluses in revenues over expenditures are contributed to the city budget.

Nacelle: Housing which contains the drive-train and other elements on top of a horizontal axis WT tower.

Natural Gas: An odorless, colorless, tasteless, non-toxic clean-burning fossil fuel. It is usually found in fossil fuel deposits and used as a fuel.

Natural Gas Hydrates: Solid, crystalline, wax-like substances composed of water, methane, and usually a small amount of other gases, with the gases being trapped in the interstices of a water-ice lattice. They form beneath permafrost and on the ocean floor under conditions of moderately high pressure and at temperatures near the freezing point of water.

Natural Gas Liquids (NGL): Substances that can be processed as liquids out of natural gas by absorption or condensation.

Net Photovoltaic Cell Shipment: The difference between photovoltaic cell shipments and photovoltaic cell purchases.

Net Photovoltaic Module Shipment: The difference between photovoltaic module shipments and photovoltaic module purchases.

Normal shutdown (WT): Shutdown in which all stages are under the control of the control system

Nonrenewable: Fuels that cannot be easily made or "renewed." We can use up nonrenewable fuels. Oil, natural gas, and coal are nonrenewable fuels.

Non-utility Generation: Electric generation by end-users, independent power producers, or small power producers under the Public Utility Regulatory Policies Act, to supply electric power for industrial, commercial, and military operations, or sales to electric utilities.

Nuclear Energy: Energy that comes from splitting atoms of radioactive materials, such as uranium.

Ocean Thermal Gradient: Differences in the temperature of layers of the ocean potentially useful for running a heat engine

Operation and Maintenance (O&M) Cost: Operating expenses are associated with operating a facility (i.e., supervising and engineering expenses). Maintenance expenses are that portion of expenses consisting of labor, materials, and other direct and indirect expenses incurred for preserving the operating efficiency or physical condition of utility plants that are used for power production, transmission, and distribution of energy.

Ozone: Three-atom oxygen compound (O3) found in two layers of the Earth’s atmosphere. One layer of beneficial ozone occurs at 7 to 18 miles above the surface and shields the Earth from ultraviolet light. Several holes in this protective layer have been documented by scientists. Ozone also concentrates at the surface as a result of reactions between byproducts of fossil fuel combustion and sunlight, having harmful health effects.

Ohm: The unit of resistance to the flow of an electric current.

Oil: The raw material that petroleum products are made from. A black liquid fossil fuel found deep in the Earth. Gasoline and most plastics are made from oil.

OPEC: The Organization of Petroleum Exporting Countries organized for the purpose of negotiating with oil companies on matters of oil production, prices, and future concession rights. Current members (as of the date of writing this definition) are Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. See OPEC's site at for more information.

Operating limits: Set of conditions defined by the WT designer that govern the activation of the control and protection system.

Organic Waste:- Waste material of animal or plant origin.

Outer Continental Shelf: Offshore Federal domain.

Parabolic Dish: A high-temperature (above 180 degrees Fahrenheit) solar thermal concentrator, generally bowl-shaped, with two-axis tracking.

Parabolic Trough: A high-temperature (above 180 degrees Fahrenheit) solar thermal concentrator with the capacity for tracking the sun using one axis of rotation.

Particulates: Visible air pollutants consisting of particles appearing in smoke or mist.

Passive Solar: A system in which solar energy alone is used for the transfer of thermal energy. Pumps, blowers, or other heat transfer devices that use energy other than solar are not used.

Passive Systems: Systems using the sun's energy without mechanical systems.

Peak Watt: A manufacturer’s unit indicating the amount of power a photovoltaic cell or module will produce at standard test conditions (normally 1,000 watts per square meter at 25 degrees Celsius).

Peak Load Plant: A plant usually housing old, low-efficiency steam units, gas turbines, diesels, or pumped-storage hydroelectric equipment normally used during the peak-load periods.

Photosynthesis: The biochemical process that utilizes radiant energy from sunlight to synthesize carbohydrates from carbon dioxide and water in the presence of chlorophyll.

Photovoltaic Cell: An electronic device consisting of layers of semiconductor materials fabricated to form a junction (adjacent layers of materials with different electronic characteristics) and electrical contacts and being capable of converting incident light directly into electricity (direct current).

Photovoltaic Conversion: Use of semi-conductors or other devices that convert solar radiation (photons) directly to electricity.

Photovoltaic Module: An integrated assembly of interconnected photovoltaic cells designed to deliver a selected level of working voltage and current at its output terminals, packaged for protection against environment degradation, and suited for incorporation in photovoltaic power systems.

Pollution: Any substances in water, soil, or air that degrade the natural quality of the environment, offend the senses of sight, taste, and smell, and/or cause a health hazard. The usefulness of a natural resource is usually impaired by the presence of pollutants and contaminants.

Plasma - A high-temperature, ionized gas composed of electrons and positive ions in such number that it is electrically neutral.

Power:- The rate at which energy is transferred. Electrical energy is usually measured in watts. Also used for a measurement of capacity.

Power Curve: A graph showing power of Wind Turbine Vs Wind Speed.

Power output: Power delivered by a device in a specific form and for a specific purpose.

Note (WT): The electric power delivered by a WT

Power Plant - A facility where power, especially electricity, is generated.

Production Tax Credit (PTC) -- Provides the owner of a qualifying facility with an annual tax credit based on the amount of electricity that is generated. By focusing on the energy produced instead of capital invested, this type of tax incentive encourages projects that perform adequately.

Protection system (WT): System which ensures that a WT remains within the design limits

Provisional Type certificate: Document issued upon the successful completion of provisional type certification

Provisional Type certification: Procedure by which a Certification Body gives written assurance that a WT type conforms to specified requirements, provisionally.

Provisional Type testing: Action of carrying out provisional tests for a given WT type according to specified procedures

Private Activity Bond (PAB): A bond in which more than 10 percent of the proceeds are secured by the interest in the property of a private business or used in a nonpublic business. A PAB can still be tax-exempt if used (at least 95 percent) for qualified investments, such as waste-to-energy facilities, and provided that State allocation caps are not exceeded.

Public Utility Regulatory Policies Act of 1978 (PURPA): One part of the National Energy Act, PURPA contains measures designed to encourage the conservation of energy, more efficient use of resources, and equitable rates. Principal among these were suggested retail rate reforms and new incentives for production of electricity by co-generators and users of renewable resources.

Public Utility Commission (PUC) or Public Services Commission (PSC): A state government agency responsible for the regulation of public utilities within a state or region. A state legislature oversees the PUC by reviewing changes to utility laws, rules and regulations and approving the PUC's budget. The commission usually has five Commissioners appointed by the governor or legislature. The PUC focuses on adequate, safe, universal utility service at reasonable rates while also trying to balance the interests of consumers, environmentalists, utilities, and stockholders.

Pulpwood: Round wood, whole-tree chips, or wood residues.

Pyrolysis: The thermal decomposition of bio-mass at high temperature in the absence of oxygen.

Quad (Q): Unit of energy equivalent to 1015 BTU.

Quadrillion Btu: Equivalent to 10 to the 15th power Btu.

Qualifying Facility (QF): A co-generation or small power production facility that meets certain ownership, operating, and efficiency criteria established by the Federal Energy Regulatory Commission (FERC) pursuant to the Public Utility Regulatory Policies Act of 1978 (PURPA). (See the Code of Federal Regulations, Title 18, Part 292.)

Radiation: Any high-speed transmission of energy in the form of particles or electromagnetic waves.

Radioactive Element: An element whose atoms have unstable nuclei that stabilizes itself by giving off radiation.

Radioactive Waste: Materials left over from making nuclear energy. Radioactive waste can harm people and the environment if it is not stored safely.

Radioactivity: The property possessed by some elements, such as uranium, of giving off alpha, beta, or gamma rays.

Receiver Panel (Solar): A panel that contains a battery of solar cells.

Reformulated Gasoline (RFG): Gasoline whose composition has been changed (from that of gasolines sold in 1990) to (1) include oxygenates, (2) reduce the content of olefins, aromatics, and volatile components, and (3) reduce the content of heavy hydrocarbons to meet performance specifications for ozone-forming tendency and for release of toxic substances (benzene, formaldehyde, acetaldehyde, 1,3-butadiene, and polycyclic organic matter) into the air from both evaporation and tailpipe emissions.

Refuse-Derived Fuel (RDF): Fuel processed from municipal solid waste that can be in shredded, fluff, or densified pellet forms.

Renewable energy: Energy derived from resources that are regenerative or for all practical purposes cannot be depleted. Types of renewable energy resources include moving water (hydro, tidal, and wave power), thermal gradients in ocean water, biomass, geothermal energy, solar energy, and wind energy. Municipal solid waste (MSW) is also considered by many to be a renewable energy resource.

Renewable Energy Sources: Fuels that can be easily made or "renewed." We can never use up renewable fuels. Types of renewable fuels are solar, wind, and hydropower energy.

Renewable Energy Resource: An energy resource that is regenerative or virtually inexhaustible. Typical examples are wind, solar, geothermal, and water power.

Restructuring: The process of changing the structure of the electric power industry from one of guaranteed monopoly over service territories to one of open competition between power suppliers for customers.

Retail Wheeling: An arrangement in which a utility transmits electricity from outside its service territory to a retail customer within its customer service territory.

Rated power: Quantity of power assigned, generally by a manufacturer, for a specified operating condition of a component, device or equipment

Note (WT): Maximum continuous electrical power output which a WT is designed to achieve under normal operating conditions.

Rated wind speed (Vr): Specified wind speed at which a WT’s rated power is achieved

Reference wind speed (Vref): Basic parameter for wind speed used for defining WT classes. Other design related climatic parameters are derived from the reference wind speed and other basic WT class parameters

Note: A WT designed for a WT class with a reference wind speed Vref, is designed to withstand climates for which the extreme 10 min average wind speed with a recurrence period of 50 years at WT hub-height is lower than or equal to Vref..

Resonance: Phenomenon appearing in an oscillating system, in which the period of a forced oscillation is very close to that of free oscillation.

Ribbon Silicon: Single-crystal silicon derived by means of fabricating processes that produce sheets or ribbons of single- crystal silicon. These processes include edge-defined film-fed growth, dendritic web growth, and ribbon-to-ribbon growth.

Rotor speed (WT): Rotational speed of a WT rotor about its axis

Roundwood: Logs, bolts, and other round timber generated from the harvesting of trees.

Salinity Gradient: A change in salinity between bodies of water or layers within a body of water.

Scrubber: An emission control device that adds alkaline reagents to react with and neutralize acid gases.

Silicon: A semiconductor material made from silica, purified for photovoltaic applications.

Single Crystal Silicon (Czochralski): An extremely pure form of crystalline silicon produced by the Czochralski method of dipping a single crystal seed into a pool of molten silicon under high vacuum conditions and slowly withdrawing a solidifying single crystal boule rod of silicon. The boule is sawed into thin wafers and fabricated into single-crystal photovoltaic cells.

Smog: Air pollution associated with oxidants.

Solar Cell: An electric cell which changes radiant energy from the sun into electrical energy by the photovoltaic process.

Solar Dish: A device that receives radiation collected by motorized collectors which track the sun. The collectors focus the radiation the energy at a focal point of the dish.

Solar Energy: The radiant energy of the sun, which can be converted into other forms of energy, such as heat or electricity.

Solar Ponds: Ponds of stratified water that collect and retain heat.

Solar Power Tower: The conceptual method of producing electrical energy from solar rays. It involved the focusing of a large number of solar rays on a single source (boiler), usually located on an elevated tower, to produce high temperatures. A fluid located in or passed through the source changes into steam and used in a turbine generator to produce electrical energy.

Solar Thermal Collector: A device designed to receive solar radiation and convert it into thermal energy. Normally, a solar thermal collector includes a frame, glazing, and an absorber, together with the appropriate insulation. The heat collected by the solar thermal collector may be used immediately or stored for later use.

Solar Thermal Collector, Special: An evacuated tube collector or a concentrating (focusing) collector. Special collectors operate in the temperature (low concentration for pool heating) to several hundred degrees Fahrenheit (high concentration for air conditioning and specialized industrial processes).

Steam: Water in vapor form; used as the working fluid in steam turbines and heating systems.

Stoker Boiler: A boiler in which fuel is burned on a grate with the fuel supplied and the ash removed continuously. Most of the steam is used for process heat, with the remainder being used for electricity if desired.

Stranded Investment: Refers to the financial impairment—not necessary plant closure in the physical sense—when the price of plant output falls to a level at which the owner can no longer earn a sufficient return on investment.

Support structure (WT): Part of a WT comprising the tower and foundation

Surveillance: Continuing monitoring and verification of the status of procedures, products and services, and analysis of records in relation to referenced documents to ensure specified requirements are met

Survival wind speed: Popular name for the maximum wind speed that a construction is designed to withstand.

Note: Design conditions instead refer to extreme wind speed.

Swept area: Projected area perpendicular to the wind direction that a rotor will describe during one complete rotation.

Switch: A device that allows the user to start or stop the flow of electricity or other movement by pressing the device on or off..

TAPS – 2000: Type Approval – Provisional Scheme (TAPS) –2000 is a scheme for provisional certification and corresponding requirements of provisional type Testing and measurements. TAPS will be in use till the formation and issue of final Type Approval Scheme (TAS) and formal accreditation. In this document, TAPS is written in place of TAPS – 2000. The reader may treat that TAPS is synonymous to TAPS - 2000.

Thermal Energy: The total potential and kinetic energy associated with the random motions of the molecules of a material.

Thermostat: A device that adjusts the amount of heating and cooling produced and/or distributed by automatically responding to the temperature in the environment.

Thermosiphon System: A solar collector system for water heating in which circulation of the collection fluid through the storage loop is provided solely by the temperature and density difference between the hot and cold fluids.

Tidal Range: The vertical distance between the high and low tide.

Tipping Fee: Price charged to deliver municipal solid waste to a landfill, waste-to-energy facility, or recycling facility.

Transformer: A device which converts the generator's low-voltage electricity to higher-voltage levels for transmission to the load center, such as a city or factory.

Transmission (Electric): The movement or transfer of electric energy over an interconnected group of lines and associated equipment between points of supply and points at which it is transformed for delivery to consumers or is delivered to other electric systems. Transmission is considered to end when the energy is transformed for distribution to the consumer.

Transmission Line: A set of conductors, insulators, supporting structures, and associated equipment used to move large quantities of power at high voltage, usually over long distances between a generating or receiving point and major substations or delivery points.

Transmission System (Electric): An interconnected group of electric transmission lines and associated equipment for moving or transferring electric energy in bulk between points of supply and points at which it is transformed for delivery over the distribution system lines to consumers or is delivered to other electric systems.

Transportation Sector (of the Economy): The part of the economy having to do with the how people and goods are transported (moved) from place to place.. The transportation sector is made up of automobiles, airplanes, trucks, and ships. trains, etc.

Transformer: An electrical device that changes the flow of electrons to match the needs of the tool being used, or the most efficient transmission (see below).

Transmission System (Electric): An interconnected group of electric transmission lines and associated equipment for moving or transferring electric energy in bulk between points of supply and points at which it is transformed for delivery over the distribution system lines to consumers, or is delivered to other electric systems.

Turbine: A machine for generating rotary mechanical power from the energy of a moving force (such as water, hot gas, wind, or steam). Turbines convert the kinetic energy to mechanical energy through the principles of impulse and reaction, or a mixture of the two.

Turbulence intensity: Ratio of the wind speed standard deviation to the mean wind speed, determined from the same set of measured data samples of wind speed, and taken over a specified period of time.

Turbulence scale parameter: Wave length where the non-dimensional, longitudinal power spectral density is equal to 0.05.

Note: The wave length is thus defined as A1 = Vhub/f0, where f0S1 (f0)/s12 = 0,05

Ultimate limit state: Limit states which generally correspond to maximum load carrying capacity (ISO 2394).

Upwind: In the direction opposite to the main wind vector

Utility Generation: Generation by electric systems engaged in selling electric energy to the public.

Vapor-Dominated Geothermal System: A conceptual model of a hydrothermal system where steam pervades the rock and is the pressure-controlling fluid phase.

Volcanic Energy: Energy produced from volcanic action.

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: 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.

Voltaic Electricity: Electricity produced by chemical action.

Waste Energy: Municipal solid waste, landfill gas, methane, digester gas, liquid acetonitrile waste, tall oil, waste alcohol, medical waste, paper pellets, sludge waste, solid byproducts, tires, agricultural byproducts, closed loop biomass, fish oil, and straw used as fuel.

Water Cycle: Water constantly moves through a vast global cycle, in which it evaporates from lakes and oceans, forms clouds, precipitates as rain or snow, then flows back to the ocean. The energy of this water cycle, which is driven by the sun, is tapped most efficiently with hydropower.

Water Heater: An automatically controlled, thermally insulated vessel designed for heating water and storing heated water at temperatures less than 180 degrees Fahrenheit.

Water Turbine: A turbine that uses water pressure to rotate its blades. Primarily used to power an electric generator.

Watt (Electric): The electrical unit of power. The rate of energy transfer equivalent to 1 ampere of electric current flowing under a pressure of 1 volt at unity power factor.

Watt (Thermal): A unit of power in the metric system, expressed in terms of energy per second, equal to the work done at a rate of 1 joule per second.

Watthour (Wh): The electrical energy unit of measure equal to 1 watt of power supplied to, or taken from, an electric circuit steadily for 1 hour.

Wavelength - The distance, measured in the direction of progression of a wave, from any given point to the next point in the same phase.

Wellhead - The point at which the crude (and/or natural gas) exits the ground.

Wheeling: The use of the transmission facilities of one system to transmit power and energy by agreement of, and for, another system with a corresponding wheeling charge, e.g., the transmission of electricity for compensation over a system that is received from one system and delivered to another system).

Wind: Air in motion. From still (no wind) to a breeze (slight wind) to a gale (mighty wind). The term given to any natural movement of air in the atmosphere. A renewable source of energy used to turn turbines to generate electricity.

Wind Machine: Devices powered by the wind that produce mechanical or electrical power.

Wind speed: At a specified point in space the wind speed is the speed of motion of a minute amount of air surrounding the specified point.

Note: The wind speed is also the magnitude of the local wind velocity (vector).

Wind Tower: Devices, some as tall as 120 feet, which lift wind turbine blades high above the ground to catch stronger wind currents.

Wind Turbine: A turbine, which converts the force of the wind into Electricity

Wind Turbine Generator System (s) – WT: System which converts kinetic energy in the wind into electrical energy.

Wind velocity: Vector pointing in the direction of motion of a minute amount of air surrounding the point of consideration, the magnitude of the vector being equal to the speed of motion of this air ”parcel” (i.e. the local wind speed).

Note: The vector at any point is thus the time derivative of the position vector of the air ”parcel” moving through the point.

Wood Energy: Wood and wood products used as fuel, including round wood (cord wood), limb wood, wood chips, bark, sawdust, forest residues, charcoal, pulp waste, and spent pulping liquor.

WT type: WT of a common design, materials and major components, subject to a common manufacturing process and uniquely described by specific values or ranges of machine parameters and design conditions

Yawing: Rotation of the rotor axis about a vertical axis (for horizontal axis WT only)

Yaw misalignment: Horizontal deviation of the WT rotor axis from the wind direction

Yellowcake: A natural uranium concentrate that takes its name from its color and texture. Yellowcake typically contains 70 to 90 percent U3O8 (uranium oxide) by weight. It is used as feedstock for uranium fuel enrichment and fuel pellet fabrication.