Turning water into watts
Huge technical and financial hurdles face anyone seeking to harness the vast power of the world’s oceans. For a devout band of researchers and hi-tech business pioneers, however, the dream of “blue energy” lives on, as Stephen Ornes discovers
In many ways, the ocean seems like the most obvious place in the world to look for energy.
Water covers about 70% of the planet, and much of it, driven by the Sun, is in constant motion. Surface swells ferry energy from one place to another, while tides and currents, as reliable as the sunrise, move vast volumes of water in very short times. The ocean is essentially a natural engine, converting solar energy into mechanical energy. Hardly surprising, then, that for at least 200 years, visionaries have dreamt of harnessing that constant, reliable motion and using it to power the world.
Numerous proposals have been made in this quest for “blue energy”, ranging from the practical to the outlandish. Perhaps the first known patent was filed in 1799 by a French family who wanted to use a lever – with one end bouncing on ocean waves – to power their sawmill and other machines. Since then, from the straits off northern Scotland to the wind-swept shelf waters near Victoria and Tasmania in Australia, scientists have been searching for the ocean’s “sweet spots”, where energy harvesting is feasible, reliable and cheap.