Scottish Power Limited is a vertically integrated energy company based in Glasgow, Scotland. It is a subsidiary of Spanish utility firm Iberdrola.
Centrica plc is a British multinational energy and services company with its headquarters in Windsor, Berkshire. Its principal activity is the supply of electricity and gas to consumers in the United Kingdom and Ireland.
The Office of Gas and Electricity Markets (Ofgem), supporting the Gas and Electricity Markets Authority, is the government regulator for the electricity and downstream natural gas markets in Great Britain. It was formed by the merger of the Office of Electricity Regulation (OFFER) and Office of Gas Supply (Ofgas).
Good Energy Group PLC is a British energy company based in Chippenham, Wiltshire that provides services in the electrification of transport and decentralised renewable energy generation such as domestic solar panels. The company is also an energy retailer, and built a portfolio of wind and solar generation which was sold in 2022. Founded by Juliet Davenport, its CEO is Nigel Pocklington.
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. It was founded in 1989 as Powergen, and was listed on the London Stock Exchange and was once a constituent of the FTSE 100 Index. It has been a subsidiary of E.ON since 1 July 2002.
Southern Electric plc was a public limited energy company in the United Kingdom between 1990 and 1998, when it merged with Scottish Hydro-Electric plc to form Scottish and Southern Energy plc. The company had its origins in the southern England region of the British nationalised electricity industry. Created in 1948 as the Southern Electricity Board, in 1990 it was privatised by being floated on the London Stock Exchange.
Npower Limited is a British supplier of gas and electricity to businesses. It has been a subsidiary of E.ON UK since January 2019. The company was formerly known as Innogy plc and was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index.
Utility Warehouse is a multiservice provider based in London, England that uses multi-level marketing to obtain customers through independent distributors. It is a brand name of its parent company, Telecom Plus. It currently handles approximately 1 million customer accounts. Utility Warehouse supplies customers with landline telephony, mobile telephony, broadband, gas, and electricity. The Utility Warehouse brand is the primary engine of revenue generation for Telecom Plus.
Uswitch Limited is a UK-based price comparison service and switching website founded in 2000. The site allows consumers to compare prices for a range of energy, personal finance, insurance, and communications services.
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. In theory these types of tariffs help to lower carbon dioxide emissions by increasing consumer demand for green electricity and encouraging more renewable energy plant to be built. Since Ofgem's 2014 regulations there are now set criteria defining what can be classified as a green source product. As well as holding sufficient guarantee of origin certificates to cover the electricity sold to consumers, suppliers are also required to show additionality by contributing to wider environmental and low carbon funds.
OVO Energy is a major energy supplier based in Bristol, England.
100Green, operating as Green Energy (UK) Ltd, is a British independent-energy company based in Ware, Hertfordshire. It was established in 2001 by CEO Douglas Stewart. The company provides Ofgem-certified renewable electricity and green gas to a variety of customers, including homes, businesses, and organizations throughout England, Wales, and Scotland. It is currently the only energy supplier in the UK to offer 100% green gas.
Co-op Energy is a membership-owned British energy supply company based in Warwick that began trading in 2010. It sells renewable electricity and gas to its ethically concerned member owner/customers and is a established large operator, an alternative to the Big Six energy suppliers. Constituting half or more of the Your Co-op Utilities division of its parent society Midcounties Co-operative, Co-op Energy is the only co-operative supplier in the British market, meaning supplied customers can voluntarily acquire an ownership share and thereby receive rights to influence the governance of the business, stand for election and have a say in formulating the products it offers.
The Big Six were the United Kingdom'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.
Solarplicity Energy Limited was a renewable energy company based in Hertfordshire, England. In August 2019 the company became the 13th energy supplier to collapse since 2018, affecting around 7,500 domestic and 500 business customers.
Spark Energy was an electricity and gas supplier in the United Kingdom, established in 2007 and headquartered in Selkirk, Scottish Borders. Its operating company Spark Energy Supply Ltd entered administration in November 2018, and industry regulator Ofgem appointed OVO Energy to take over Spark Energy's 290,000 customer accounts; OVO continues to run Spark as a separate brand, but is in the process of migrating all its customers to the SSE brand.
Extra Energy Supply Ltd was an independent retail energy supplier based in Birmingham, England. It supplied gas and electricity to domestic and small business customers. Extra Energy was part of Extra Holding, which operates in industries including telecoms, travel, insurance and energy.
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 Centrica, the parent company of British Gas.
Octopus Energy Group is a British renewable energy group specialising in sustainable energy. It was founded in 2015 with the backing of British fund management company Octopus Group, a British asset management company. Headquartered in London, the company has operations in the United Kingdom, France, Germany, Italy, Spain, Australia, Japan, New Zealand and the United States. Following the acquisition of Shell Energy on 1 December 2023, Octopus Energy is the UK's second largest domestic energy provider.
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 as the new supplier of Pure Planet's customers.
