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.

Canadian Solar Inc. (NASDAQ: CSIQ) is a global renewable energy company.

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.

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.

Energy Conversion Devices, Inc. (ECD) was an American photovoltaics manufacturer of thin-film solar cells made of amorphous silicon used in flexible laminates and in building-integrated photovoltaics.

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,…

Renewable energy (also called green energy) is energy made from renewable natural resources that are replenished on a human timescale. The most widely used renewable energy types are solar energy, wind power, bioenergy/biomass, and hydropower.