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.