Definition: A middle distillate and form of heating oil used primarily in heating and air conditioning units.


Gas Year


Definition: In the UK, the gas year begins at 6:00am on the 1st of October. This is also known as the contract year, as it is when the purchase of contracts begin.




Definition: The process of producing electrical energy by transforming other forms of energy. The amount of energy produced is expressed in watt-hours.




Definition: Producer of electricity.


German Power Index


Definition: An electricity price index for the whole of Germany, launched by Dow Jones in Jan 2001.


Gigawatt (GW)


Definition: A unit of power equal to 1,000MW/1,000,000kW.


Greenhouse Gas (GHG)


Definition: A gas in an atmosphere that absorbs and emits radiation. The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone.


Grid Supply Point (GSP)


Definition: The point at which energy is taken from the National Grid transmission system into a local distribution system.


Grid Trade Master Agreement (GTMA)


Definition: A legal document that sets out the terms of the agreement with regard to financially settling a contract and physically delivering power.