Glossary

Energy glossary

747 definitions · page 10 of 13.

POWER POOL: An entity established to coordinate short-term operations to maintain system stability and achieve least-cost dispatch. The dispatch provides backup supplies, short-term excess sales, reactive power support, and spinning reserve. Historically, some of these…
PPM (PARTS PER MILLION): The unit commonly used to represent the degree of pollutant concentration where the concentrations are small.
PREFERRED DAY-AHEAD SCHEDULE: A Scheduling Coordinator's preferred schedule for the ISO day-ahead scheduling process.
PREFERRED HOUR-AHEAD SCHEDULE: A Scheduling Coordinator's preferred schedule for the ISO hour-ahead scheduling process.
PREFERRED SCHEDULE: The initial schedule produced by a Scheduling Coordinator that represents its preferred mix of generation to meet demand. The schedule includes the quantity of output (generators) and consumption (loads), details of any adjustment bids, and the location of…
PRESSURIZED WATER REACTOR (PWR): A nuclear power unit cooled by water that is pressurized to keep it from boiling when it reaches high temperatures.
PRIMARY FUEL: Fuel consumed in the original production of energy, before conversion takes place.
PROGRAMMABLE CONTROLLER: A device that controls the operation of electrical equipment (such as air conditioning units and lights) according to a preset time schedule.
PROPANE: A gas that is both present in natural gas and refined from crude oil. It is used for heating, lighting and industrial applications. See also LPG.
PROVIDER OF LAST RESORT: A legal obligation(traditionally given to utilities) to provide service to a customer where competitors have decided they do not want that customer's business.
PUBLIC ADVISER: A appointee of the governor who attends all meetings of the California Energy Commission and provides assistance to members of the public and intervenors in cases before the Commission.
PUBLIC INTEREST GOALS: Public interest goals of electric utility regulation include: 1) inter-and intra-class and intergenerational equity); 2) the equal treatment of equals (horizontal equity); 3)balancing long- and short-term goals that have the potential to affect…
PUHCA: The Public Utility Holding Company Act of 1935. This act prohibits acquisition of any wholesale or retail electric business through a holding company unless that business forms part of an integrated public utility system when combined with the utility's…
PUMPED HYDROELECTRIC STORAGE: Commercial method used for large-scale storage of power. During off-peak times, excess power is used to pump water to a reservoir. During peak times, the reservoir releases water to operate hydroelectric generators.
Purchased Capacity: The amount of energy and capacity available for purchase from outside the system.
PURPA: The Public Utility Regulatory Policy Act of 1978. Among other things, this federal legislation requires utilities to buy electric power from private "qualifying facilities," at an avoided cost rate. This avoided cost rate is equivalent to what it would have…
PX: The California Power Exchange Corporation, a state chartered, non-profit corporation charged with providing Day-Ahead and Hour-Ahead markets for energy and ancillary services, if it chooses to self-provide, in accordance with the PX tariff. The PX is a…
PX GENERATION: Generation being scheduled by the PX.
PX LOAD: Load that has been scheduled by the PX, and which is received through the use of transmission or distribution facilities owned by participating transmission owners.
PX PARTICIPANT: An entity that is authorized to buy or sell energy or ancillary services through the PX, and any agent authorized to act on behalf of such an entity.
QUAD: One quadrillion (1015 or 1,000,000,000,000,000) British thermal units (Btus). An amount of energy equal to 170 million barrels of oil. Total U.S. consumption of all forms of energy is (in the 1990s) about 83 quads in an average year.
QUALIFYING FACILITY: A cogenerator or small power producer which under federal law, has the right to sell its excess power output to the public utility.
QUALIFYING FACILITY (QF): Under PURPA, QFs were allowed to sell their electric output to the local utility at avoided cost rates. To become a QF, the independent power supplier had to produce electricity with a specified fuel type (cogeneration or renewables), and meet certain…
R-VALUE: A unit of thermal resistance used for comparing insulating values of different material. It is basically a measure of the effectiveness of insulation in stopping heat flow. The higher the R-value number, a material, the greater its insulating properties and…
RAD: A unit of measure of absorbed radiation. Acronym for radiation absorbed dose. One rad equals 100 ergs of radiation energy per gram of absorbing material.
RADIANT BARRIER: A device designed to reduce or stop the flow of radiant energy.
RADIANT ENERGY: Energy transferred by the exchange of electromagnetic waves from a hot or warm object to one that is cold or cooler. Direct contact with the object is not necessary for the heat transfer to occu.
RADIATION: The flow of energy across open space via electromagnetic waves such as light. Passage of heat from one object to another without warming the air space in between.
RANKINE CYCLE: The steam-Rankine cycle employing steam turbines has been the mainstay of utility thermal electric power generation for many years. The cycle, as developed over the years uses superheat, reheat and regeneration. Modern steam Rankine systems operate at a…
RATE-BASING: refers to practice by utilities of allotting funds invested in utility Research Development Demonstration and Commercialization and other programs from ratepayers, as opposed to allocating these costs to shareholders.
RAW FUEL: Coal, natural gas, wood or other fuel that is used in the form in which it is found in nature, without chemical processing.
RDF (REFUSE DERIVED FUEL): The fuel component of municipal solid waste (MSW), which is the by-product of shredding MSW to a uniform size, screening out oversized materials and isolating ferrous material in magnetic separation. The resulting RDF can be burned as a fuel source.
REACTOR: A device in which a controlled nuclear chain reaction can be maintained, producing heat energy.
REAL-TIME MARKET: The competitive generation market controlled and coordinated by the ISO for arranging real-time imbalance energy.
REAL-TIME PRICING: The instantaneous pricing of electricity based on the cost of the electricity available for use at the time the electricity is demanded by the customer.
RECLAIMED OIL: Lubricating oil that is processed to be used over again.
RECOOL: The sensible cooling of air that has been previously heated by HVAC systems serving the same building. [See California Code of Regulations, Title 24, Section 2-5302]
RECOVERED ENERGY: Reused heat or energy that otherwise would be lost. For example, a combined cycle power plant recaptures some of its own waste heat and reuses it to make extra electric power.
RECOVERY EFFICIENCY: (Thermal efficiency) Ia water heater, a measure of the percentage of heat from the combustion of gas which is transferred to the water as measured under specified test conditions. California Code of Regulations, Section 2- 1602(e)(7).
REFINER: means any person who owns, operates, or controls the operations of one or more refineries.
REFINERY: A facility that separates crude oil into varied oil products. The refinery uses progressive temperature changes to separate by vaporizing the chemical components of crude oil that have different boiling points. These are distilled into usable products such…
REFORMULATED GASOLINE (RFG): A cleaner-burning gasoline that has had its compositions and/or characteristics altered to reduce vehicular emissions of pollutants. It was sold in California beginning in 1996 with the oxygenate additive MTBE.
REFRIGERANT: A fluid such as freon that is used in cooling devices to absorb heat from surrounding air or liquids as it evaporates.
REGULATION: The service provided by generating units equipped and operating with automatic generation controls that enables the units to respond to the ISO's direct digital control signals to match real-time demand and resources, consistent with establsihed operating…
REGULATORY MUST-RUN GENERATION: Utilities will be allowed to generate electricity when hydro resources are spilled for fish releases, irrigation, and agricultural purposes, and to generate power that is required by federal or state laws, regulations, or jurisdictional authorities. Such…
REGULATORY MUST-TAKE GENERATION: Utilities will be allowed to generate electricity from those resources -- identified by the CPUC -- that are not subject to competition. These resources will be scheduled with the ISO on a must-take basis. Regulatory Must-Take Generation includes QF…
REHEAT: The heating of air that has been previously cooled either by mechanical refrigeration or economizer cooling systems.
REID VAPOR PRESSURE (RVP): a standard measurement of a liquid's vapor pressure in pounds per square inch at 100 degrees Fahrenheit. It is an indication of the propensity of the liquid to evaporate.
RELIABILITY: Electric system reliability has two components-- adequacy and security. Adequacy is the ability of the electric system to supply the aggregate electrical demand and energy requirements of the customers at all times, taking into account scheduled and…
RELIABILITY MUST RUN UNIT: In return for payment, the ISO may call upon the owner of a generating unit to run the unit when required for grid reliability.
RELIABILITY MUST-RUN GENERATION: The ISO will allow utilities to generate power that is needed to ensure system reliability. This includes generation: Required to meet the reliability criteria for interconnected systems operation. Needed to meet load (demand) in constrained areas. Needed to…
RENEWABLE ENERGY: Resources that constantly renew themselves or that are regarded as practically inexhaustible. These include solar, wind, geothermal, hydro and wood. Although particular geothermal formations can be depleted, the natural heat in the earth is a virtually…
RENEWABLE RESOURCES: Renewable energy resources are naturally replenishable, but flow-limited. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Some (such as geothermal and biomass) may be stock-limited in that…
REREGULATION: The design and implementation of regulatory practices to be applied to the remaining regulated entities after restructuring of the vertically-integrated electric utility. The remaining regulated entities would be those that continue to exhibit…
RESEARCH AND DEVELOPMENT (R&D): Research is the discovery of fundamental new knowledge. Development is the application of new knowledge to develop a potential new service or product. Basic power sector R&D is most commonly funded and conducted through the Department of Energy (DOE), its…
RESERVE: The extra generating capability that an electric utility needs, above and beyond the highest demand level it is required to supply to meet its users¼ needs.
Reserve Capacity: Extra generating capacity available to meeet peak or abnormally high demands for power and to generate power during scheduled or unscheduled outages. Units available for service, but not maintained at operating temperature, are termed "cold." those units…
RESERVE GENERATING CAPACITY: The amount of power that can be produced at a given point in time by generating units that are kept available in case of special need. This capacity may be used when unusually high power demand occurs, or when other generating units are off-line for…
RESERVE MARGIN: The differences between the dependable capacity of a utility's system and the anticipated peak load for a specified period.
RESIDENTIAL BUILDING: means any hotel, motel, apartment house, lodging house, single and dwelling, or other residential building which is heated or mechanically cooled.