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.