Renewable Energy Certificate (United States)
Renewable Energy Certificates (RECs), also known as Green tags, Renewable Energy Credits, Renewable Electricity Certificates, or Tradable Renewable Certificates (TRCs), are tradable, non-tangible energy certificates in the United States that represent proof that 1 megawatt-hour (MWh) of electricity was generated from…
Net metering in the United States
Net metering is a policy by many states in the United States designed to help the adoption of renewable energy. Net metering was pioneered in the United States as a way to allow solar and wind to provide electricity whenever available and allow use of that electricity whenever it was needed, beginning with utilities…
Power purchase agreement
A power purchase agreement (PPA), or electricity power agreement, is a long-term contract between an electricity generator and a customer, usually a utility, government or company. PPAs may last anywhere between 5 and 20 years, during which time the power purchaser buys energy at a pre-negotiated price.
Feed-in tariff
A feed-in tariff (FIT, FiT, standard offer contract, advanced renewable tariff, or renewable energy payments) is a policy mechanism designed to accelerate investment in renewable energy technologies by offering long-term contracts to renewable energy producers. This means promising renewable energy producers an…
Ice storage air conditioning
Ice storage air conditioning is a form of thermal energy storage in which cooling capacity is stored by freezing water and recovered later by melting the ice. In building applications, the storage can be charged when cooling demand or electricity prices are lower and discharged during periods of higher cooling demand,…
Concentrated solar power
Concentrated solar power (CSP), also called concentrating solar power or concentrated solar thermal, involves systems that collect solar heat for multiple purposes like cooking, desalination, or the generation of electric solar power, by using mirrors to concentrate a large area of sunlight toward a receiver. …
Phoenix Energy
Phoenix Energy (formerly Phoenix Natural Gas) is the largest gas distribution business in Northern Ireland, being the owner and operator of the licence for the distribution network in the Greater Belfast area. The distribution business is responsible for the development of the pipeline network and also for providing a…
Energy in the United States
Energy in the United States is obtained from a variety of sources, although the majority came from fossil fuels in 2025: 37% of the nation's energy originated from petroleum, 36% from natural gas, and 9% from coal. Electricity from nuclear power supplied 9% and renewable energy supplied 9%, which includes biomass,…
Pure Planet
Pure Planet was a British energy supply company 24% owned by BP. The company, which was founded in 2015 and based in Bath, England, supplied electricity and gas to domestic customers in the UK. It ceased trading on 13 October 2021 following BP's withdrawal of support. On 17 October, Ofgem appointed Shell Energy (a…
Energy superpower
An energy superpower is a country that supplies large amounts of energy resources (crude oil, natural gas, coal, etc.) to a significant number of other countries - and therefore has the potential to influence world markets for political or economic gains. Energy superpower status might be exercised, for example, by…