The Big Six were Great Britain's largest retail suppliers of gas and electricity, who dominated the market following liberalisation in the late 1990s. By 2002, six companies – British Gas, EDF Energy, E.ON, RWE npower, Scottish Power and SSE – had emerged from the 15 former incumbent monopoly suppliers (the 14…

E.ON UK is a British energy company and one of the largest suppliers of energy in the UK, following its acquisition of Npower. It is a subsidiary of E.ON of Germany and one of the Big Six energy suppliers.

Outfox Energy, the trading name of Foxglove Energy Supply Limited, is a British energy supplier based in Leicester, United Kingdom. It was founded in 2017.

Utilita Energy is an electricity and gas supplier operating in the United Kingdom. Utilita began trading in 2003, specialising in pay-as-you-go metering.

OVO Energy is an energy supplier based in Bristol, England. It was founded by Stephen Fitzpatrick and began trading energy in September 2009, buying and selling electricity and gas to supply domestic properties throughout the UK. By June 2017, OVO had 680,000 customers, an increase of 10,000 over the previous year,…

A feed-in tariff (FIT) is paid by energy suppliers in the United Kingdom if a property or organisation generates their own electricity using technology such as solar panels or wind turbines and feeds any surplus back to the grid. The FIT scheme was imposed on suppliers by the UK government, and applied to…

Aggreko is a global supplier of mobile and modular power, temperature control equipment and energy services, headquartered in Glasgow, United Kingdom. The business was founded in 1962 and previously listed on the London Stock Exchange from 1997 to 2021.

npower Business Solutions is a British supplier of gas and electricity to large businesses. It has been a subsidiary of E.ON UK since January 2019.

Ferrellgas Partners, L.P. is an American supplier of propane founded in 1939 in Atchison, Kansas by A.C. Ferrell. The nationwide company is headquartered in Liberty, Missouri.

The availability and uptake of green electricity in the United Kingdom has increased in the 21st century. There are a number of suppliers offering green electricity in the United Kingdom.