The Canary island of El Hierro, which produces most of its electricity from wind, is the focus of the premiere episode of the series, which examines islands that have embraced sustainable energy.

On the Portuguese island of Madeira, the inhabitants are converting an irrigation system from the 15th century into a future-age energy storage facility.

The Orkney Islands, which is studying whether tides and waves can be turned into an energy source, are spotlighted.

A look at the Baltic island of Samso, which produces more energy than it can use from wind turbines and straw-fuelled thermal power stations.

Iceland's embrace of volcanic hydro power and geothermal energy, which provides almost all of its electricity, is detailed. Also: its effort to run all cars and its enormous fishing fleet on hydrogen.