A bicycle pump-like device that harnesses wave power to generate electricity could be coming to the United Kingdom’s coast within the next few years. The surprisingly simple system gets around a huge hurdle facing wave power: corrosion.
The “Searaser” device works a little like an air pump for a bike, only it’s much larger and pushes water around. Searaser contains a piston between two buoys, a larger one that floats on the ocean surface, and a smaller one suspended underwater that’s weighted to the seafloor. When ocean waves pass by, the motion causes the piston to pump seawater through a pipe toward the shore.
British engineer Alvin Smith was inspired to create the device while playing with an inflatable ball at a swimming pool, according to the BBC.
Once ashore, Searaser sends the water uphill through the pipe to a reservoir. That seawater then gets released and comes downhill to an on-shore turbine, where electricity is produced. The BBC has a short animation showing how this works.
Some might see similarities between the Searaser and other buoy-like systems. OPT’s PowerBuoy system also uses buoys to capture wave power but relies on an underwater cable to transmit the power ashore. The ocean environment is especially tough on electrical equipment, though. It corrodes a lot of the materials needed to make an underwater wave-power system work.
By focusing on pumping seawater alone, Smith’s design neatly avoids subjecting power generation and transmission equipment to the corrosive ocean:
Searaser was acquired by the British energy firm Ecotricity, which already created a prototype and plans to have the device ready for market in two years. A full-sized Searaser would be about 3.5 feet wide and 40 feet deep. Smith told the BBC he thinks that one will cost around $385,000.
Ideally, the system would be placed near a cliff that has a reservoir at the top. Fortunately for the British, the U.K. has more than 150 such reservoirs around the southwest. How well will it work? For now it’s hard to tell, but 200 Searasers could power more than 230,000 homes. That’s quite the cycle.