The government has awarded a £6.5 million grant to a geothermal energy project in Wales.
The project in Bridgend will pump naturally-heated water from an old coal mine called the Caerau Colliery and use it to heat 150 homes.
The scheme, which is estimated to cost a total of around £9.4 million, will pump water at a temperature of 20.6°C from a depth of 230 metres into a heat exchanger, where it will warm the water used in people’s homes.
The mine water then flows back underground to be heated again.
The British Geological Survey suggests the scheme could eventually heat 1,000 households and help slash energy bills by up to £100 a year per person.
Construction work is expected to start in 2020 with the first 150 homes being heated by late 2021.
Cabinet Secretary for Energy, Lesley Griffiths, said: “This is a cutting-edge model of generating a clean source of renewable energy, drawing on the legacy of our coal mining heritage.”