Glossary by "P"
Cells or batteries connected as follows: all positive terminals are connected together and all negative terminals are connected together. An important effect is that the output current from cells/battery connected in parallel is additive whereas the voltage remains at the characteristic voltage.Source: ESA Technical Working Group
The maximum power draw from end-user loads during specified times. For example, most utilities experience peak demand during hot summer afternoons.Source: ESA Technical Working Group
An electric supply resource, typically a combustion turbine generator or reciprocating engine, whose primary purpose is to generate electricity when peak demand occurs.Source: ESA Technical Working Group
Performance based ratemakingAcronym(s): PBR
Regulated rate-of-return is established primarily based upon the utility’s “performance objectives,” rather than cost.Source: ESA Technical Working Group
Performance-based regulationAcronym(s): PBR
Regulatory provisions that sets a utility’s authorized rate-of-returns and profit based on the degree to which the utility meets or exceeds specified performance criteria which may include emission control, public benefits, labor practices and cost of service, among others. In some cases utilities that meet PBR criteria may be allowed to reduce or maintain energy prices and in other cases the utility may be allowed to operate under fewer regulatory or legal constraints.Source: ESA Technical Working Group
Phasor measurement unitAcronym(s): PMU
A device that enables synchronized measurement of electrical wave forms on the electricity grid. Synchronization is accomplished using a common time source for synchronization (e.g. global positioning system). That synchronization enables real-time measurements of status/conditions for geographically diverse points within the grid. PMUs may be separate devices or they may be incorporated into a protective relay or other device. PMUs are poised/expected to be an important element of the smarter, more diverse, more distributed electricity grid of the future. PMUs are also known as synchrophasors.Source: ESA Technical Working Group
An interruption of electric generation, transmission or distribution operation which is planned.Source: ESA Technical Working Group
The responsible entity that coordinates and integrates transmission facility and service plans, resource plans, and protection systems.
Plug-in electric vehicleAcronym(s): PEV
An electric vehicle that can be connected to the electric grid for charging and/or to supply electricity to the gridSource: ESA Technical Working Group
Plug-in hybrid electric vehicleAcronym(s): PHEV
A hybrid electric vehicle that can be connected to the electric grid for charging and/or to supply electricity to the gridSource: ESA Technical Working Group
Point of deliveryAcronym(s): POD
A location that the Transmission Service Provider specifies on its transmission system where an Interchange Transaction leaves or a Load-Serving Entity receives its energy.
Point of receiptAcronym(s): POR
A location that the Transmission Service Provider specifies on its transmission system where an Interchange Transaction enters or a Generator delivers its output.
Point to point transmission serviceAcronym(s): PTP
The reservation and transmission of capacity and energy on either a firm or non-firm basis from the Point(s) of Receipt to the Point(s) of Delivery.
The terminal of a battery into which electrons flow, through the load, during cell/battery discharge.Source: ESA Technical Working Group
The stored energy associated with a mass that is related to the mass’ position. See also elastic potential energy and gravitational potential energy.Source: ESA Technical Working Group
The rate at which energy is generated, converted, transmitted, distributed or delivered.Source: ESA Technical Working Group
The level of power that a storage system can provide per unit volume occupied by the system.Source: ESA Technical Working Group
Electronic devices, methods and systems used to convert power with a specific form to power with a desired form. For example, power electronics is used to convert direct current electric power to alternating current electric power and vice versa.Source: ESA Technical Working Group
Power exchangeAcronym(s): PX
A marketplace for sale and purchase of wholesale electricity (energy and capacity).Source: ESA Technical Working Group
the ratio of real power to apparent powerSource: ESA Technical Working Group
Power factor adjustment
A charge levied on commercial and industrial electricity end-users that reflects metered power factor that is lower than a specified threshold.Source: ESA Technical Working Group
Power factor correction
Adjusting the power factor towards unity, through the injection or absorption of reactive poweralso provide power factor correction.Source: ESA Technical Working Group
Power qualityAcronym(s): PQ
A measure of the level of voltage and/or frequency disturbances.Source: Power2Switch
A battery comprised of primary cells. A non-rechargeable battery.Source: ESA Technical Working Group
A cell whose an electrochemical reaction is not intended to be reversible (i.e., once the cell is fully discharged it is not or cannot be recharged. Primary cells may be classified based on the electrolyte involved.Source: ESA Technical Working Group
Pro forma tariff
Usually refers to the standard OATT and/or associated transmission rights mandated by the U.S. Federal Energy Regulatory Commission Order No. 888.
Protective relays, associated communication systems, voltage and current sensing devices, station batteries and DC control circuitry.
Services provided or offered by utilities “for the public good.” Public benefits may include, for example, cost reductions associated with energy efficiency programs, use of renewable energy resources, assistance for low-income customers, research and development, programs that improve environmental quality and services which enhance reliability of transmission systems.Source: ESA Technical Working Group
Public benefits charge
A modest charge added to customer’s electricity billing commensurate with costs related to services that a utility provides “in the public interest.” They apply, for example, if a utility is required—by law and/or regulation—to provide public interest services which may include education, assistance for low-income customers, environmental and efficiency programs and research and development. Before deregulation; public interest charges were collected and managed by the utility, with regulatory oversight or public-interest organizations. After deregulation; it is increasingly common for charges to be placed into a public trust, to be managed by an independent third party or advisory board, possibly with regulatory oversight.Source: ESA Technical Working Group
Public utility commissionAcronym(s): PUC
The state agency that regulates the activities of investor-owned utilities (and also municipal utilities in some states).Source: Power2Switch
The entity that purchases or sells, and takes title to, energy, capacity, and Interconnected Operations Services. Purchasing-Selling Entities may be affiliated or unaffiliated merchants and may or may not own generating facilities.