Definition: Any marketer, broker, public agency, city, county, or special district that combines loads of multiple end-use customers in facilitating the sale and purchase of electric energy, transmission, and other services on behalf of these customers.




Definition: A UK medium-range gas storage facility.


American Gas Association (AGA)


Definition: An association that represents companies involved in all areas of the transmission and distribution of natural gas in the United States of America.


American Petroleum Institute 2 (API 2)


Definition: The benchmark price reference for coal imported into northwest Europe. The API 2 price is the primary price reference for physical and over-the-counter (OTC) coal contracts in northwest Europe. Some 90% of the world’s coal derivatives are priced against the Argus/McCloskey API 2 and API 4 indexes.


American Petroleum Institute 4 (API 4)


Definition: The price index for coal shipments free-on-board Richards Bay. Can be seen in Argus/IHS McCloskey Coal Price Index, and the South African Coal Report. Utilized less frequently than the API 2 Index for forward purchases of coal.


Amsterdam Power Exchange (APX)


Definition: An exchange that runs spot market platforms across Europe (formerly UKPX in the UK).


Amsterdam Rotterdam Antwerp (ARA)


Definition: A coal pricing hub


Anaerobic Digestion (AD)


Definition: A natural process in which micro-organisms break down the organic matter found in wet biomass waste (such as sewage sludge, animal manure and slurry, and waste food) in the absence of oxygen, to produce biogas (mainly a mixture of around 60% methane and 40% carbon dioxide) and digestate (a nitrogen-rich fertilizer).


Ancillary Service


Definition: Necessary service that must be provided in the generation and delivery of electricity. As defined by the Federal Energy Regulatory Commission, they include coordination and scheduling services (load following, energy imbalance service, control of transmission congestion), automatic generation control (load frequency control and the economic dispatch of plants), contractual agreements (loss compensation service), and support of system integrity and security (reactive power, or spinning and operating reserves).


APX Reference Price Data (APX RPD)


Definition: A market data product that provides a volume-weighted reference price for each half-hour settlement period each day where such data is available.




Definition: The practice of taking advantage of a price difference between two or more markets.


Associated Gas


Definition: Natural gas found in a crude oil reservoir, separated from or in solution with the oil.




Definition: The percentage of the time that an electricity generating plant is available to produce electricity.