The services necessary to effect a transfer of electricity between purchasing and selling entities that transmission providers must include in their open access transmission tariffs; IOSs are the voluntary services that transmission providers may offer to their customers (FERC Order 888, April 24, 1996). Ancillary services include regulation and frequency response; reactive supply and voltage control from generating sources, economic dispatch, and the like
The measure of time that a generating unit, transmission line or other facility is capable of providing service, whether the unit, line or facility is in service (expressed as a percent available for the time under consideration)
The interconnected operations service that provides the needed capacity and energy to transmission customers to replace the loss of generation and to cover the portion of demand that exceeds generation supplies for more than a short period
Any consumer of electrical energy; also, the amount of power (demand) used by a utility system, electrical device or consumer. Load can be manually or automatically curtailed or shed temporarily during times of high usage (customers have agreed beforehand to such actions) or managed to ensure a reliable electricity supply
Reducing electricity use from the grid during peak periods to increase reliability and moderate the energy-clearing price during system-wide peak demand; reducing electric load or using qualifying emergency generators on the customer side of the meter.
The difference between net capacity (a system's total capacity resources) and net internal demand, that is generally expressed in MW for operating reserves and as a percentage of either system load or installed generating capacity for planning reserves
The cost of providing additional electricity; "The competitive price of a MWh of electricity is equal to the additional amount it would cost to generate an additional MWh, once all current demand is met. This additional cost is commonly referred to as the marginal cost. The marginal cost of generating electricity rises as more electricity is produced, because different generators use different types and amounts of fuel_.under competition, the rising marginal cost of electricity leads to high prices when demand is high and low prices during low-demand periods." (GAO-02-828 Restructured... Read more about Marginal Cost
The measure of performance of a bulk-power system that results in electricity being delivered to consumers within accepted standards and in the amount desired; measured by frequency, duration and magnitude of adverse impacts on the electric supply (also called system reliability). Reliability comprises both generation adequacy and system security.
An agreed-upon transaction size (measured in MW), start and end times, start and end ramp times and rates required for delivery and receipt of power and energy between contracting parties and the control areas involved in the transaction