"It actually takes quite a lot of fossil fuel power to reach the tiny Spanish island of El  Hierro. You have to catch a commercial jet flight, a propeller plane and then a ferry to reach what was once the end of the known world, before Columbus set sail."

"But once you're there, there's no need for fossil fuels at all. The ancient island off the west coast of Africa is now a model for the future, within months of running on 100 percent renewable energy, which consists of a mix of wind and hydro-power."

"El Hierro, the most remote of Spain's Canary Islands, is now billing itself as the world's first energy self-sufficient island that has never been hooked up to a power grid."

"A Danish island, Samso, is also energy-independent, but was previously hooked up to the Danish grid and didn't make the change in isolation, like El Hierro."