Glossary

Energy glossary

747 definitions · page 3 of 13.

CO-OP: This is the commonly used term for a rural electric cooperative. Rural electric cooperatives generate and purchase wholesale power, arrange for the transmission of that power, and then distribute the power to serve the demand of rural customers. Co-ops…
COAL: Black or brown rock, formed under pressure from organic fossils in prehistoric times, that is mined and burned to produce heat energy.
COAL CONVERSION: Changing coal into synthetic gas or liquid fuels. See GASIFICATION.
COAL OIL: Oil that can be obtained by distilling bituminous coal.
COAL SEAM: A mass of coal, occurring naturally at a particular location, that can be commercially mined.
COAL SLURRY PIPELINE: A pipe system that transports pulverized coal suspended in water.
COGENERATION: Cogeneration means the sequential use of energy for the production of electrical and useful thermal energy. The sequence can be thermal use followed by power production or the reverse, subject to the following standards:
COGENERATOR: Cogenerators use the waste heat created by one process, for example during manufacturing, to produce steam which is used, in turn, to spin a turbine and generate electricity. Cogenerators may also be QFs.
COKE: A porous solid left over after the incomplete burning of coal or of crude oil.
COKE OVEN GAS: Gas given off by coke ovens. Coke oven gas is interchangeable with goal gas.
COMBINED CYCLE PLANT: An electric generating station that uses waste heat from its gas turbines to produce steam for conventional steam turbines.
COMBINED HYDRONIC SPACE/WATER HEATING: a system in which both space heating and domestic water heating are provided by the same water heater(s).
COMBUSTION Burning: Rapid oxidation, with the release of energy in the form of heat and light.
COMFORT CONDITIONING: The process of treating air to simultaneously control its temperature, humidity, cleanliness, and distribution to meet the comfort requirements of the occupants of the conditioned space.
COMFORT ZONE: The range of temperatures over which the majority of persons feel comfortable (neither too hot nor too cold).
COMMERCIALIZATION: Programs or activities that increase the value or decrease the cost of integrating new products or services into the electricity sector. (See "Sustained Orderly Development.")
COMPETITIVE TRANSMISSION CHARGE: A non-bypassable charge that customers pay to a utility for the recovery of its stranded costs.
COMPRESSED NATURAL GAS (CNG): natural gas that has been compressed under high pressure, typically between 2,000 and 3,600 pounds per square inch, held in a container. The gas expands when released for use as a fuel.
CONDENSATE: Liquid fuel obtained by burning gas or vapor produced from oil and gas wells.
CONDENSER: A heat exchanger in which the refrigerant, compressed to a hot gas, is condensed to liquid by rejecting heat.
CONDITIONED FLOOR AREA: The floor area of enclosed conditioned spaces on all floors measured from the interior surfaces of exterior partitions for nonresidential buildings and from the exterior surfaces of exterior partitions for residential buildings. [See California Code of…
CONDITIONED SPACE: Enclosed space that is either directly conditioned space or indirectly conditioned space. [See California Code of Regulations, Title 24, Section 2-5302]
CONDITIONED SPACE, DIRECTLY: An enclosed space that is provided with heating equipment that has a capacity exceeding 10 Btus/(hr-ft2), or with cooling equipment that has a capacity exceeding 10 Btus/(hr-ft2). An exception is if the heating and cooling equipment is designed and…
CONDUCTANCE: The quantity of heat, in Btu's, that will flow through one square foot of material in one hour, when there is a 1 degree F temperature difference between both surfaces. Conductance values are given for a specific thickness of material, not per inch thickness.
CONDUCTION: The transfer of heat energy through a material (solid, liquid or gas) by the motion of adjacent atoms and molecules without gross displacement of the particles.
CONDUCTIVITY (k): The quantity of heat that will flow through one square foot of homogeneous material, one inch thick, in one hour, when there is a temperature difference of one degree Fahrenheit between its surfaces.
CONGESTION: A condition that occurs when insufficient transfer capacity is available to implement all of the preferred schedules simultaneously.
CONGESTION MANAGEMENT: Alleviation of congestion by the ISO.
CONSERVATION: Steps taken to cause less energy to be used than would otherwise be the case. These steps may involve improved efficiency, avoidance of waste, reduced consumption, etc. They may involve installing equipment (such as a computer to ensure efficient energy…
CONTINENTAL SHELF: The portion of the sea bottom that slopes gradually from the edge of a continent. Usually defined as areas where water is less than 200 meters or 600 feet deep.
CONTINGENCY PLANNING: The Energy Commission's strategy to respond to impending energy emergencies such as curtailment or shortage of fuel or power because of natural disasters or the result of human or political causes, or a clear threat to public health, safety or welfare. The…
CONTRACT PATH: The most direct physical transmission tie between two interconnected entities. When utility systems interchange power, the transfer is presumed to take place across the "contract path," notwithstanding the electrical fact that power flow in the network will…
CONTRACTS FOR DIFFERENCES (CFD): A type of bilateral contract where the electric generation seller is paid a fixed amount over time which is a combination of the short-term market price and an adjustment with the purchaser for the difference. For example, a generator may sell a distribution…
CONTROL AREA: An electric power system, or a combination of electric power systems, to which a common automatic generation control (AGC) is applied to match the power output of generating units within the area to demand. The control area of the ISO is the state of…
CONVECTION: Transferring heat by moving air, or transferring heat by means of upward motion of particles of liquid or gas heat from beneath.
CONVENTIONAL GAS: Natural gas occurring in nature, as opposed to synthetic gas.
CONVERSION: device or kit by which a conventional fuel vehicle is changed to an alternative fuel vehicle.
CONVERSION FUEL FACTOR: A number stating units of one system in corresponding values of another system.
CONVERTED VEHICLE: a vehicle originally designed to operate on gasoline that has been modified or altered to run on an alternative fuel.
CONVERTER: Any technology that changes the potential energy in a fuel into a different from of energy such as heat or motion. The term also is used to mean an apparatus that changes the quantity or quality of electrical energy.
COOLING CAPACITY LATENT: Available refrigerating capacity of an air conditioning unit for removing latent heat from the space to be conditioned.
COOLING CAPACITY SENSIBLE: Available refrigerating capacity of an air conditioning unit for removing sensible heat from the space to be conditioned.
COOLING CAPACITY TOTAL: Available refrigerating capacity of an air conditioner for removing sensible heat and latent heat from the space to be conditioned.
COOLING CAPACITY, LATENT: Available refrigerating capacity of an air conditioning unit for removing latent heat from the space to be conditioned.
COOLING DEGREE DAY: A unit of measure that indicates how heavy the air conditioning needs are under certain weather conditions.
COOLING LOAD: The rate at which heat must be extracted from a space in order to maintain the desired temperature within the space.
COOLING LOAD TEMPERATURE DIFFERENCE (CLTD): A value used in cooling load calculations for the effective temperature difference (delta T) across a wall or ceiling, which accounts for the effect of radiant heat as well as the temperature difference.
COOLING TOWER: A device for evaporatively cooling water by contact with air.
COOPERATIVE (Electric utility): A joint venture organized by consumers to make electric utility service available in their area.
COP (COEFFICIENT OF PERFORMANCE): Used to rate the performance of a heat pump, the COP is the ratio of the rate of useful heat output delivered by the complete heat pump unit (exclusive of supplementary heating) to the corresponding rate of energy input, in consistent units and under…
CORD: A measure of volume, 4 by 4 by 8 feet, used to define amounts of stacked wood available for use as fuel. Burned, a cord of wood produces about 5 million calories of energy.
CORPORATE AVERAGE FUEL ECONOMY (CAFE): A sales-weighted average fuel mileage calculation, in terms of miles per gallon, based on city and highway fuel economy measurements performed as part of the federal emissions test procedures. CAFE requirements were instituted by the Energy Policy and…
CRUDE OIL: Petroleum as found in the earth, before it is refined into oil products. Also called CRUDE.
CRUDE OIL STOCKS: Stocks held at refineries and at pipeline terminals. Does not include stocks held on leases (storage facilities adjacent to the wells). In California, crude oil stocks in 1990 are approximately 18 million barrels on any given day.
CSE (CALIFORNIA SEASONAL EFFICIENCY): See See Seasonal Efficiency.
CUBIC FOOT: The most common unit of measurement of natural gas volume. It equals the amount of gas required to fill a volume of one cubic foot under stated conditions of temperature, pressure and water vapor. One cubic foot of natural gas has an energy content of…
DAY-AHEAD MARKET: The forward market for energy and ancillary services to be supplied during the settlement period of a particular trading day that is conducted by the ISO, the PX, and other Scheduling Coordinators. This market closes with the ISO's acceptance of the final…
DAY-AHEAD SCHEDULE: Day-ahead Schedule A schedule prepared by a Scheduling Coordinator or the ISO before the beginning of a trading day. This schedule indicates the levels of generation and demand scheduled for each settlement period of that trading day.
DAYLIGHTING: The use of sunlight to supplement or replace electric lighting.
DAYLIGHTING CONTROL: A control system that varies the light output of an electric lighting system in response to variations in available daylight.