Octopus Energy has been named the largest domestic energy provider in Great Britain, a year after becoming the biggest electricity supplier.
The utility company’s rise to the top, with a 23.7% share of the available market, is the first time the top position has changed since the energy retail market opened for competition in the 1990s following the deregulation of the energy market in the 1980s.
Although Octopus has been the biggest electricity supplier since April 2024, Centrica-owned British Gas had held the overall largest market share because of its dominance in the gas supply market.
Octopus Energy Group is valued at US$9 billion (£7.2 billion), nine years after launching in the UK market. The company is now active in 26 countries and purports to be one of the largest specialist investors in renewable power in Europe, managing a £7 billion portfolio. Earlier this week, our sister site PV Tech reported that the company had acquired French agrivoltaics (agriPV) developer OX2 France from OX2 AB as part of its plans to invest over €1 billion (£8.4 million) in French clean energy by the end of 2025.
Greg Jackson, founder of Octopus Energy, said the company became Britain’s biggest energy supplier by “relentlessly” delivering on service, cost reductions and innovation. He added: “We have invested heavility in technology to deliver this rare combination of rapid growth and outstanding service.”
Octopus Energy takes biggest UK energy market share
Figures from Cornwall Insight’s Domestic Energy Market Share Survey shows that Octopus serves 12.9 million household energy accounts and its market share is 0.6% higher than the supplier with the second-largest share of the market.
Over half of suppliers left the energy market during the 2020 energy crisis that followed the COVID-19 pandemic, and six energy companies now hold over 90% of the household energy market. In 2019, Cornwall Insight says small and medium energy suppliers held over a 30% share of the domestic energy market; now, only 8.9% of the market is held by small and medium suppliers outside the Big Six.
Octopus’ rise was further aided by the fortunes of Shell Energy Retail and Bulb, both of which took place throughout 2023. Following Octopus’ takeover of the business in late 2023, 1.3 million households transferred over from Shell Energy Retail, and 1.5 million customers were also transferred from failed energy supplier Bulb.
The utility continued to lead the switching market through 2024, with just under one million customers joining from other suppliers.
CEO of Cornwall Insight Dan Morris called the change “quite honestly the biggest development in the domestic retail energy market since it opened”.
He continued: “Octopus Energy started from zero market share in 2015 and has worked its way up to the top spot on this measure in less than a decade. This is a notable achievement in the highly competitive and tightly regulated UK supplier market.”
Still, as Morris noted, an “element of caution” should be maintained. Nationalisation of the transmission and distribution grids, as well as the Big Six suppliers, formed a central part of Labour’s energy pledges in its 2019 manifesto.
The Big Six was, at the time, made up of British Gas, EDF Energy, E.ON, Npower, Scottish Power and SSE. It was effectively reduced to a ‘Big Five’ when E.On acquired Npower in 2019, and in 2020 the original Big Six came to an end when OVO Energy acquired SSE.
At the height of their influence, the Big Six supplied seven out of ten British households with gas and electricity, according to consumer energy comparison guide Uswitch.
Morris said: “Consumer choice remains a critical factor for both households and businesses when selecting their energy supplier. With the household energy market now once again dominated by six major companies – albeit a different set than the Big Six of old – some may argue that consumers aren’t benefiting from the same level of competition or deals seen in the years leading up to the crisis.”