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.

Enphase Energy, Inc. is an American energy technology company headquartered in Fremont, California, that develops and manufactures solar micro-inverters, battery energy storage, and EV charging stations primarily for residential customers.

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.

Fox ESS Co., Ltd. (Chinese: 麦田能源股份有限公司), trading as Fox ESS, is a Chinese manufacturer of photovoltaic inverters and battery energy storage systems headquartered in Wenzhou, Zhejiang.

Co-op Energy is a membership-owned British energy supply company based in Warwick that began trading in 2010. It sells renewable electricity (some from community-owned sources) and gas to its ethically concerned member owner/customers and is an established large operator, an alternative to the Big Six energy suppliers.

SolaX Power Network Technology (Zhejiang) Co., Ltd. (Chinese: 艾罗能源), commonly known as SolaX Power or SolaX, is a Chinese manufacturer of solar inverters and energy-storage products headquartered in Hangzhou, Zhejiang.

Robin Hood Energy was a not-for-profit energy company launched in September 2015 by Nottingham City Council as a competitor to the "big six" energy suppliers in the United Kingdom. The company supplied gas and electricity nationally to homes and businesses until September 2020, when its customer accounts were sold to…

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,…