Outside the white-walled town of Moura in the rolling plans of southern Portugal, more than 240,000 solar panels covering an area equivalent to 150 football pitches are slowly being manoeuvred into position in what will be the world's biggest photovoltaic power plant. A few kilometres away, at Alqueva, the Guadiana river has been dammed to create the largest reservoir in western Europe and one of 18 hydroelectric power projects under way in Portugal's river valleys. In the north-west Alto Minho region, one of the world's biggest wind farms is under construction.

A string of three red steel tubes, each the size of a railway carriage, lies low in the water off the northern coast of Portugal. As the snub-nosed apparatus rises and dips in the Atlantic waves, it becomes immediately clear why this pioneering energy technology is called Pelamis after a mythical giant sea snake. Later this year, these wave energy converters, developed over many years of testing by Edinburgh-based Pelamis Wave Power, will be pumping electricity into Portugal's national grid, making it the first country in the world to harness wave energy on a commercial basis.