Who are the big six?
The big six energy suppliers are still the largest companies in the UK's energy sector today. Details on each and their customer numbers are listed below:
British Gas
British Gas is the largest energy company and the greenest supplier of the six. It has now become a branch of Centrica PLC, although in Scotland it is known as Scottish Gas in and in Wales as Nwy Prydain. Its main offices are located in Berkshire. The company supplies gas to 15 million UK households, with 6 million electricity customers.
EDF Energy
This is the British branch of the French company EDF, supplying more than 5.6 million customers. EDF Business Energy has the largest low carbon electricity production with the majority of its supply generated from nuclear sources.
E.ON
E.ON, formerly Powergen, is well known for business and private power supply, currently serving 5 million customers. The company is renowned for its innovative approach and advanced technology focused on harnessing green energy.
Npower
Npower is the smallest of the big six energy suppliers. Outside of domestic supply, it focuses on expanding wind and hydroelectric power. Npower is now a subsidiary of E.ON, although they continue to operate separately. It also cooperates with Sainsbury's Energy.
Scottish Power
Scottish Power is the next largest company above Npower and one of the longest-running provider groups in the UK. It supplies electricity and gas to over 5 million UK households. This is a leading company in renewable energy, after recently closing down its gas and coal plants.
SSE
Scottish and Southern Energy (SSE) is the second-largest supplier in the UK and the second-best provider of renewable power. In 2020, it was bought by supplier OVO but continues to operate under the SSE brand. It specialises in hydropower and electric power.
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