Wave-power gets a boost

Pacific Gas & Electric has agreed to buy electricity generated from wave-power farm, Finavera Renewables.

The project hasn’t been approved by the U.S. government yet but finding someone who is willing to buy from the farm is a major step toward making it a reality.

The wave-power farm, scheduled for completion by 2012, will generate electricity from eight specially equipped buoys located off the coast of Northern California and will collectively generate up to two megawatts of power. If all goes as planned and the project is granted the necessary approvals, it could be expanded to produce up to 100 megawatts.

A full-scale buoy from Finavera will be capable of generating 250 kilowatts, enough for 80 homes. The 2-megawatt field will consist of eight devices. The planned 100-megawatt array could be squeezed into a few square miles on the sea.

Another experimental wave generator plant in operation is Pelamis Wave Power operating out of Portugal and Scotland. Pelamis has developed a method of offshore wave energy collection, using a floating tube called "Pelamis". This long, hinged tube (about the size of 5 railway cars) bobs up and down in the waves on hinges that pumps hydraulic fluid which drives generators.

Sea water is more than 800 times denser than air at sea level, which means wave farms or tidal turbines can produce quite a bit of power with only a little equipment and real estate.

Ten years from now, the U.S. could produce 10 gigawatts of wave power and 3 gigawatts of tidal power, said Roger Bedard, ocean energy program leader for the Electric Power Research Institute and an admitted optimist on the subject. That's enough for 4.3 million homes (assuming 3 kilowatts a home).

Wave energy is transferred to electricity by generators placed on the surface of the ocean in the shape of buoys or tubes. Energy output is determined by wave height, wave speed, wavelength, and water density.

Advantages of wave energy is that there is no fuel needed and no waste produced therefore it is energy free. It is not expensive to operate, and can produce a great deal of energy.

Disadvantages are that it depends on waves, sometimes you get a lot of energy other times none. It needs a suitable site where waves are consistently strong and it must be able to withstand very rough weather.

It won’t answer all of the worlds energy needs but this technology is on the cutting edge of being an important part of the patchwork of energy sources the U.S. will need to power our homes and businesses while addressing the ever looming climate change.