Flow Energy was an energy supplier in the United Kingdom owned by Co-op Energy. Its headquarters were in Ipswich, Suffolk. The company was launched as a small independent domestic energy supply company in April 2013, supplying gas and electricity to homes throughout the UK. Flow Energy was acquired by Co-op Energy in May 2018, and the Flow brand continued to be used until August 2019 when the customers were acquired by Octopus Energy.
Flow Energy also developed a household electricity-generating gas boiler, the Flow boiler, which provided heating and hot water and also generated electricity, using patented technology.