Not every energy supplier has the staying power to survive intense competition, rising wholesale prices, and shifting regulations. Over the past decade, dozens of companies have disappeared — some through insolvency, others through mergers or simple closure. Below are several lesser-known energy firms that once aimed to make their mark but ultimately failed or faded away.
Composite Energy Ltd
Founded in Scotland in 2003, Composite Energy specialised in coal bed methane extraction — a cleaner alternative to traditional fossil fuels. The company operated exploration projects across central Scotland and Wales but struggled with high operational costs and environmental objections. It was acquired by Dart Energy in 2011, which itself was later taken over by Santos Ltd, effectively ending the Composite Energy brand.
7 Energy Ltd
7 Energy Ltd was a small renewable energy developer focused on solar and biomass projects. Based in the Midlands, it supplied sustainable heating and power solutions for commercial and agricultural clients. Despite early success in rural installations, the company went into liquidation in 2016 as subsidy cuts and volatile fuel prices squeezed smaller operators out of the market.
Mongoose Energy
Mongoose Energy was a Bristol-based cooperative that aimed to revolutionise community energy ownership. Established in 2015, it helped local groups build and manage renewable projects such as solar farms and hydro plants. Despite strong ideals, the business model relied heavily on government feed-in tariffs, which were drastically reduced in 2019. Mongoose Energy eventually ceased trading, with its remaining assets absorbed by community partners.
Sapphire Energy Inc
Sapphire Energy, an American biofuel firm with operations linked to UK research partnerships, once attracted major investment for its innovative “green crude” made from algae. The company hoped to commercialise biofuels as a sustainable replacement for petroleum, but the technology proved expensive to scale. By 2017, Sapphire Energy had effectively wound down operations after selling key assets to a biotechnology company.
Billington Bioenergy Ltd
Billington Bioenergy Ltd (BBE), part of the Billington Group, supplied wood pellets and biomass fuel for domestic and business heating. Founded in 2009, it grew alongside the rise of renewable heat incentives but struggled when demand flattened and raw material costs rose. In 2016, BBE was acquired by Drax Group and later integrated into Drax Biomass Supply — marking the end of Billington Bioenergy as a standalone business.
Roar Power
Roar Power launched in 2019 as a partnership between energy supplier Octopus Energy and Exeter City Council. The brand positioned itself as a community-minded, 100% renewable supplier offering fair pricing and local reinvestment. However, the initiative was short-lived; Roar Power was quietly closed in 2021 as energy price volatility made it unsustainable. Customers were moved over to Octopus Energy.
Northumbria Energy
Northumbria Energy was a small UK gas and electricity supplier that entered the domestic and SME markets in 2017. Despite competitive rates, it struggled to establish a foothold against larger brands. Following persistent financial difficulties, the company ceased trading in 2019, with Ofgem appointing British Gas to take over its customer base.
One Select
One Select entered the UK energy market in 2017 offering low-cost tariffs to small households. Like many budget suppliers, it was hit hard by rising wholesale prices and inadequate hedging. Ofgem revoked its licence in December 2018 after financial difficulties, transferring 36,000 customers to Together Energy. The collapse highlighted how quickly small suppliers could fail in a volatile market.
Colorado Energy Ltd
Colorado Energy was a London-based gas and electricity supplier that aimed to provide transparent pricing and better customer service. It launched in 2019 but failed to withstand the extreme price surges of 2021, which saw dozens of energy firms collapse. In October 2021, Colorado Energy ceased trading, with Shell Energy appointed as its supplier of last resort.
Lessons from a turbulent sector
The fall of these companies demonstrates how challenging the UK energy market can be — particularly for smaller or niche suppliers. Volatile wholesale prices, tight margins, regulatory complexity, and the pressure to decarbonise have forced even innovative firms to close.
Yet, each played a part in shaping the current landscape. Their rise and fall underscore the importance of sound financial planning, strong supply partnerships, and adaptability — qualities that today’s leading suppliers must master to avoid becoming the next forgotten name in the energy industry.