New Advances in Gleaning Energy From Water

In the race to commercialize renewable energy technologies, the various newer forms of hydro-energy aren’t even contenders. Watery environments are chaotic special cases that modern engineering has yet to defeat.

Still, there are occasionally advances that might give one a glimmer of hope. As it happens, there are three new items to report, one for each of the three big areas of hydro (besides dams): wave power, tidal power, and osmotic power.

• Wave power — Queens University Belfast, in Northern Ireland, is touting their new Oyster generator, which they just turned on, as the “largest wave energy device in the world”.

  The Oyster looks significantly different from most other wave power generators: A flat base rests on the seabed, supporting a stiff upper chamber that’s pushed back and forth by the waves. A hydraulic pump pushes water through a tube to an on-shore generator, which produces electricity. The University is starting work on a second version of the Oyster.

• Tidal power – Sometimes, tidal power means the device is sitting right on the beach catching incoming waves, but for OpenHydro (also an Irish company) it means three kilometers offshore. The company just installed a turbine in Canada’s Bay of Fundy with Nova Scotia Power; when it’s operating (as the tide goes in or out) it generates a megawatt of power. Greentech Media has a video on the company.

• Osmotic power — This one is definitely the weirdest of the bunch, and the least tested. There are slight differences in the charge and volume of salty and fresh water; the theory is that a power plant situated where salty and fresh meet, such as the mouth of a river, could harvest some of this energy.

  Norway’s Statkraft uses a membrane that draws fresh water through, creating pressure that can drive a turbine. Their launch, unlike the two mentioned above, is only a tiny pilot project. But the Statkraft executive in charge of the project is urging fast development, with the claim that osmosis could provide half of Europe’s power.