New Oyster design promises more wave energy output


The new 800-kilowatt device can produce 250 percent more electricity than the original Oyster 1. Photo from Aquamarine Power
Edinburgh, Scotland-based Aquamarine Power has improved its hydroelectric wave energy device to generate clean, renewable electricity from the ocean’s waves more efficiently.
Dubbed the Oyster 2 wave energy converter, the new 800-kilowatt device can produce 25 percent more electricity than the original Oyster 1 and is simpler to install and maintain.
Aquamarine Power claimed that a small farm of 20 Oyster 2 devices can provide enough energy to power more than 12,000 homes. In contrast, a farm with 20 units of Oyster 1 can only power around 9,000 homes.
The first prototype of the original device wasinstalled and tested at the European Marine Energy Center in Orkney, Scotland in 2009.
Aquamarine Power will deploy three units of the improved version at the marine center by June 2011. All three devices will be linked to an onshore 2.4-megawatt hydroelectric turbine.
“When Oyster 2 is installed next summer it will be another step on our journey to building the world’s first commercial wave farm,” said Martin McAdam, chief executive of Aquamarine Power.
The original Oyster device has a mechanical hinged flap anchored to the seabed. Each passing wave activates two hydraulic pistons to deliver high-pressure water onshore via a pipeline. The water is then converted to electricity by hydroelectric generators.
“The design concept remains exactly the same, but we have improved every element of that design, from the size and shape of the Oyster flap, to the hydraulic power take off and pipeline system,” Mr. McAdam says.
Aquamarine Power said its wave hydroelectric device offers various advantages. One benefit is that the device stays onshore, allowing for easier maintenance than when underwater components are used.
The system is also placed at a relatively shallow depth where sea waves are more consistent, making power delivery consistent as well.
Lastly, the device relies only on water for the hydraulic, rather than oil, thus minimizing the environmental risks involved. The Carbon Trust, an independent nonprofit company established by the British government, estimates that each Oyster device can avoid 500 tons of carbon dioxide annually.
Ronan Doherty, chief technical officer of Aquamarine Power, found that coastlines off Spain, Portugal, Ireland, Britain, United States, South Africa, Australia and Chile are ideal places to install the devices. He also predicted that the potential size of the market could be in excess of £50 billion ($71.69 billion).