The Association for Decentralised Energy (ADE), formerly the Combined Heat and Power Association, is a trade association that supports the growth of decentralised energy systems, such as district heating systems. The association is based in London.

Emerald Energy plc is an energy exploration subsidiary of Chinese state-owned company Sinochem with headquarters in London but is registered offshore in the Isle of Man. The company specialises in oil exploration and production of hydrocarbons.

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.

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.

A battery energy storage system (BESS), battery storage power station, battery energy grid storage (BEGS) or battery grid storage is a type of energy storage technology that uses a group of batteries in the grid to store electrical energy. Battery storage is the fastest responding dispatchable source of power on…

Pharos Energy Plc, previously SOCO International, is an oil and gas exploration and production company, headquartered in London. The company changed its name to Pharos Energy Plc in October 2019 after coming under fire for illegal activity in Virunga.

Essar Energy plc is Mauritius-based Indian energy company with assets in the power and oil and gas businesses. Headquartered in Port Louis, Mauritius and subsidiary of Essar Group, the firm has interests in both the power generation and petroleum industries.

Ophir Energy plc was an oil and gas exploration and production company based in London. It owned both operating and non-operating assets in Africa, Asia, and Mexico.

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,…