The energy minister, Charles Hendry, is to visit Iceland in May to discuss connecting the UK to its abundant geothermal energy. "We are in active discussions with the Icelandic government and they are very keen," Hendry told the Guardian. To reach Iceland, which sits over a mid-ocean split in the earth's crust, the cable would have to be 1,000 to 1,500km long and by far the longest in the world.

Hendry has already met the head of Iceland's national grid about the plan. The web of sea-floor cables – called interconnectors – planned for the next decade would link the UK to a Europe-wide supergrid, which is backed by the prime minister. The supergrid would combine the wind and wave power of northern Europe with solar projects such as Desertec in southern Europe and north Africa to deliver reliable, clean energy to meet climate change targets and reduce dependence on fossil fuel imports.