Wave Energy

Moving water stores massive amounts of energy. The trick is how to get at it and use it. Building water wheels on fast flowing rivers to grind grain is one of the few ideas mankind has come up with — not too helpful if you don’t live near fast flowing water. Damming rivers and using the released water to turn turbines is an obvious spin-off –again you need rivers, though not necessarily fast flowing. The environmental damage caused by dams, however, has been more and more noticed in recent decades — from depleted downstream run off, to earthquakes caused by the weight of the dammed up water.

With rising concern about climate change caused by the re-release of old CO2 back into the atmosphere, attention has turned to the largest sources of water energy — the oceans. How to harness the waves, tides and currents? Lot’s of interesting ideas being floated (heh heh), from bioWave turbines that mimic kelp, swaying on the ocean floor, to watermills that spin with the inflow and outflow of the tides, to Finavera’s aquabouys which rise and fall on the waves and tides there are a surge of innovative ideas.

Add Green Ocean’s WaveTreader to the list.

wave_treader

The WaveTreader is a further development of the initial OceanTreader, attaching the free standing design to fixed columns supporting windmills at sea, to get a double hit from wind and water.

The Treader comprises a Sponson at the front, a Spar Buoy in the center and a second Sponson at the aft end. As the wave passes along the device first the forward Sponson lifts and falls, then the Spar Buoy lifts and falls slightly less and finally the aft Sponson lifts and falls. The relative motion between these three floating bodies is harvested by hydraulic cylinders mounted between the tops of the arms and the Spar Buoy. The cylinders pressurise hydraulic fluid which, after smoothing by accumulators, spins hydraulic motors and then electric generators. The electricity is exported via a cable piggy-backed to the anchor cable..

Eco Geek

New website with some uplifting content: EcoGeek.org [And look in the center column for a list of related web-sites.]

Finavera AquaBouy

Finavera Renewables has just successfully deployed its second generation AquaBuOY, a wave generation plant that weighs nearly 40 tons and is 75 feet long. Only about ten feet of the device shows above the water. As the buoy rocks up and down in the surf, it generates power with an internal generator.

That power can then be shipped back to shore via an underwater transmission cable. The bouy’s huge size allows it to harness a great deal of the moving water’s massive energy. No word, however, on how much energy each of these will produce. But, as with wind and solar, wave power only has up-front costs. Once the project is in place, the “fuel” that creates the power is free.

Finavera alraedy has about 250 megawatts of wave power planned or under development in America. The AquaBuOY 2.0 wave farm off the coast of Oregon could be underway as soon as 2010.