Glossary

Energy glossary

747 definitions · page 7 of 13.

HOT DRY ROCK: A geothermal resource created when impermeable, subsurface rock structures, typically granite rock 15,000 feet or more below the earth's surface, are heated by geothermal energy. The resource is being investigated as a source of energy production.
HSPF (Heating Seasonal Performance Factor): A measure of heating efficiency for the total heating output of a central air-conditioning heat pump. Efficiency is derived according to federal test methods by using the total Btus during its normal usage period for heating divided by the total electrical…
HVAC (Heating Ventilation and Air Conditioning): A system that provides heating, ventilation and/or cooling within or associated with a building.
HYBRID VEHICLE: Usually a hybrid EV, a vehicle that employs a combustion engine system together with an electric propulsion system. Hybrid technologies expand the usable range of EVs beyond what an all-electric-vehicle can achieve with batteries only.
HYDROELECTRIC POWER: Electricity produced by falling water that turns a turbine generator. Also referred to as HYDRO.
HYDROELECTRIC SPILL GENERATION: Hydroelectric generation in existence prior to January 1, 1998, that has no storage capacity and that, if backed down, would spill. This term also refers to a hydro resource that has exceeded or has inadequate storage capacity and is spilling, even though…
HYDRONIC HEATING: A system that heats a space using hot water which may be circulated through a convection or fan coil system or through a radiant baseboard or floor system.
HYDROTHERMAL SYSTEMS: Underground reservoirs that produce either dry steam or a mixture of steam and water.
HYGAS: A process that uses water to help produce pipeline-quality gas from coal.
ILEV (Inherently Low Emission Vehicle): Term used by federal government for any vehicle that is certified to meet the California Air Resources Board's Low Emission Vehicle (LEV) standards for non-methane organic gases and carbon monoxide, ULEV standards for nitrogen oxides and does not emit any…
IMBALANCE ENERGY: The real-time change in generation output or demand requested by the ISO to maintain reliability of the ISO-controlled grid. Sources of imbalance energy include regulation, spinning and non-spinning reserves, replacement reserve, and energy from other…
IMPORTS (Electric utility): Power capacity or energy obtained by one utility from others under purchase or exchange agreement.
IMPOUNDMENT: A body of water confined by a dam, dike, floodgate or other artificial barrier.
IN-SITU COMBUSTION: An experimental means of recovering hard-to-get petroleum by burning some of the oil in its natural underground reservoir. Also called FIREFLOODING.
IN-SITU GASIFICATION: Converting coal into synthetic gas at the place where the coal is found in nature.
INCANDESCENT LAMP: An electric lamp in which a filament is heated by an electric current until it emits visible light.
INDEPENDENT POWER PRODUCER: An Independent Power Producer (IPP) generates power that is purchased by an electric utility at wholesale prices. The utility then resells this power to end-use customers. Although IPPs generate power, they are not franchised utilities, government agencies…
INDIGENOUS ENERGY RESOURCES: Power and heat derived from sources native to California. These include geothermal, hydro, biomass, solar and wind energy. The term usually is understood to include cogeneration facilities.
INFILTRATION: The uncontrolled inward leakage of air through cracks and gaps in the building envelope, especially around windows, doors and duct systems.
INFILTRATION BARRIER: A material placed on the outside or the inside of exterior wall framing to restrict inward air leakage, while permitting the outward escape of water vapor from the wall cavity. [See California Code of Regulations, Title 24, Section 2-5302]
INFRASTRUCTURE: generally refers to the recharging and refueling network necessary to successful development, production, commercialization and operation of alternative fuel vehicles, including fuel supply, public and private recharging and refueling facilities, standard…
INJECTION: (Petroleum) -- Forcing gas or water into an oil well to increase pressure and cause more oil to come to the surface. See THERMALLY ENHANCED OIL RECOVERY.
INSOLATION: The total amount of solar radiation (direct, diffuse, and reflected) striking a surface exposed to the sky.
Installed (or Nameplate) Capacity: The total manufacturer-rated capacities of equipment such as turbines, generators, condensers, transformers, and other system components.
INSULATION THERMAL: A material having a relatively high resistance of heat flow and used principally to retard heat flow. See R-VALUE.
INSULATION, THERMAL: A material having a relatively high resistance of heat flow and used principally to retard heat flow. See R-VALUE.
INTEGRATED RESOURCE PLANNING PRINCIPLES: The underlying principles of IRP can be distinguished from the formal process of developing an approved utility resource plan for utility investments in supply- and demand-side resources. A primary principle is to provide a framework for comparing a variety…
INTEGRATED RESOURCE PLANNING(IRP): A public planning process and framework within which the costs and benefits of both demand- and supply-side resources are evaluated to develop the least-total-cost mix of utility resource options. In many states, IRP includes a means for considering…
INTERCHANGE (Electric utility): The agreement among interconnected utilities under which they buy, sell and exchange power among themselves. This can, for example, provide for economy energy and emergency power supplies.
INTERCONNECTION (Electric utility): The linkage of transmission lines between two utilities, enabling power to be moved in either direction. Interconnections allow the utilities to help contain costs while enhancing system reliability.
INTERESTED PARTY: any person whom the commission finds and acknowledges as having a real and direct interest in any proceeding or action carried on, under, or as a result of the operation of, this division.
INTERNAL COMBUSTION ENGINE: An engine in which fuel is burned inside the engine. A car's gasoline engine or rotary engine is an example of a internal combustion engine. It differs from engines having an external furnace, such as a steam engine.
INTERRUPTIBLE SERVICE (Electric utility): Electricity supplied under agreements that allow the supplier to curtail or stop service at times.
INTERTIE: A transmission line that links two or more regional electric power systems.
INVESTOR-OWNED UTILITIES: A private company that provides a utility, such as water, natural gas or electricity, to a specific service area. The investor-owned utility is regulated by the California Public Utilities Commission. In California the investor owned utilities supplying…
ION: An atom or group of atoms that is electrically charged
IOU: An investor owned utility. A company, owned by stockholders for profit, that provides utility services. A designation used to differentiate a utility owned and operated for the benefit of shareholders from municipally owned and operated utilities and rural…
IPP: INDEPENDENT POWER PRODUCER. An private entity that operates a generation facility and sells power to electric utilities for resale to retail customers.
ISDN: INTEGRATED SERVICES DIGITAL NETWORK. A 128 Kbps(kilobytes per second) digital telephone service available in many parts of the country though not universally available thatmay be able to substitute for fiber optic cable in every respect except possibly…
ISO -- INDEPENDENT SYSTEM OPERATOR: A neutral operator responsible for maintaining instaneous balance of the grid system. The ISO performs its function by controlling the dispatch of flexible plants to ensure that loads match resources available to the system.
JOULE: A unit of work or energy equal to the amount of work done when the point of application of force of 1 newton is displaced 1 meter in the direction of the force. It takes 1,055 joules to equal a British thermal unit. It takes about 1 million joules to make a…
KEROSENE: Certain colorless, low-sulfur oil products that burn without producing much smoke.
KILOVOLT (kv): One-thousand volts (1,000). Distribution lines in residential areas usually are 12 kv (12,000 volts).
KILOWATT (kW): One thousand (1,000) watts. A unit of measure of the amount of electricity needed to operate given equipment. On a hot summer afternoon a typical home, with central air conditioning and other equipment in use, might have a demand of four kW each hour.
KILOWATT-HOUR (kWh): The most commonly-used unit of measure telling the amount of electricity consumed over time. It means one kilowatt of electricity supplied for one hour. In 1989, a typical California household consumes 534 kWh in an average month.
LADWP: The acronym for Los Angeles Department of Water and Power an electric, municipal utility serving the greater Los Angeles, California, region.
LANDFILL GAS: Gas generated by the natural degrading and decomposition of municipal solid waste by anaerobic microorganisms in sanitary landfills. The gases produced, carbon dioxide and methane, can be collected by a series of low-level pressure wells and can be processed…
LASER: A very intense, uniform beam of electromagnetic radiation. Acronym for Light Amplification by Simulated Emission of Radiation.
LATENT HEAT: A change in the heat content that occurs without a corresponding change in temperature, usually accompanied by a change of state (as from liquid to vapor during evaporation).
LATENT LOAD: The cooling load caused by moisture in the air.
LATITUDE: The angular distance north or south of the equator, measured in degrees of arc.
LAY UP: Lay up is another term for cold storage and describes the status of equipment (such as a power plant) that has been placed in storage ("mothballed") for latter use.
LAYOFF (Electric utility): Excess capacity of a generating unit, available for a limited time under the terms of a power sales agreement.
LEADED GASOLINE: Gasoline containing tetraethyl lead, an important constituent in antiknock gasoline. Leaded gasoline is no longer sold in the United States.
LIFE EXTENSION: A term used to describe capital expenses which reduce operating and maintenance costs associated with continued operation of electric utility boilers. Such boilers usually have a 40 year operating life under normal circumstances.
LIFE-CYCLE COST: Amount of money necessary to own, operate and maintain a building over its useful life.
LIFELINE RATES: Rates charged by a utility company for the low income, the disadvantaged and senior citizens. The rates provide a discount for minimum necessary utilities, such as electricity requirements of typically 300 to 400 kilowatt/hours per month.
LIGHT WATER REACTOR (LWR): A nuclear power unit that uses ordinary water to cool its core. The LWR may be a boiling water reactor or a pressurized water reactor.
LIGNITE: Brownish black coal having qualities in between those of bituminous coal and peat. The texture of the original wood often is visible in lignite.
LIQUEFACTION: The process of making synthetic liquid fuel from coal. The term also is used to mean a method for making large amounts of gasoline and heating oil from petroleum.