WAVE POWER COMES OF AGE

WAVE POWER: The inexhaustible potential of the oceans for energy production is on its way to becoming realised. A wave power machine has proved that it is viable and the way is now open to commercial electricity production

Imagine an enormous, 40 cylinder car engine lying in the water, whose only fuel is the waves. Rows of floats do the job of pistons, raising and lowering as the waves glide through the engine, the motion converting mechanical energy into electrical energy – in one long, infinite sequence that will only stop when the oceans cease to have waves.

 “And that will never happen as long as the earth is structured as it is,” says Per Resen Steenstrup, director of Wave Star Energy. “The weather may be calm or it may be stormy but there are always waves, either high whitecaps or large, lazy swells. Our wave energy machine constantly has something to work with.”

Surviving storms

Wave Star Energy will be among the first in the world to present a full-scale operational wave power machine with an output of 6 MW. So far, the company’s 1:10 scale model has been working without interruption for 10,000 hours. The test machine has survived seven storms, three of which were extreme.

“The test machine has proved that we have got the right technology,” says Steenstrup. “There is constant continuity in the electricity production; we have solved the storm-proofing issue in a simple and effective way and by basing our components on known and thoroughly tested materials and technologies, we have achieved an exploitation level that is better than even the best wind turbines.” Problems regarding storm-proofing have turned out to be especially tricky with other known wave energy machines. In contrast to other machines that float on water, the Wave Star machine is fixed to a steel pile construction. It has a builtin hydraulic system that can lift up the entire construction, so that the movable floats are lifted out of the water during very severe storms. Commercial electricity production “History is filled with spectacular wrecks of wave power machines, which effectively stopped further development,” says Steenstrup. “We have solved that problem, so now we are producing a 1:2 scale machine that will generate electricity out in the North Sea about 10 kilometres off the Danish coast. It will be located near the world’s first large offshore wind turbine park at Horns Rev, have an output of 500 kW and will be directly connected to the wind turbines’ electricity grid.” Wave Star Energy’s objective is to be competitive on price with the largest off-shore wind turbines, which Per Resen Steenstrup sees happening in 10 to 15 years, taking into account that wind turbines have been under development for 25 years to reach where they are today.

“An ordinary offshore wind turbine only exploits around 40% of its capacity because of varying wind. Our machine exploits 50 to 55%, primarily because in addition to functioning when there are ordinary waves, it also exploits the ocean swell which is there all the time.” The 1:2 scale machine at Horns Rev will be ready for operation in 2009. It will be batch-produced and form the model for a later, full-size machine.

http://www.wavestarenergy.com