Turning waves into electricity

(Nanowerk News) In 1993, diver Rauno Koivusaari was exploring a wreck in the Gulf of Finland when he realised that waves could be harnessed to generate power. Over two decades on, the WaveRoller energy converter, built by Koivusaari’s company AW-Energy, has demonstrated its effectiveness during a two-year trial off Peniche, Portugal, funded through the EU’s loan programme.
AW-Energy estimates that one converter could provide electricity for 440 homes. With the device now deployed in Chile, France and Ireland, as well as Portugal, the company aims to sell more than 50 units by 2020.
As well as being predictable, experts believe that waves are the largest untapped clean energy resource, with more potential than all of Europe’s fossil fuel plants combined.
“It is calculated that wave energy could satisfy at least one tenth of the world's energy needs,” says AW-Energy communications chief Mikael Martikainen.
However, cost and vulnerability to rough sea have long made finance for the technology difficult to find. “Until the EIB came into the picture, there was no bank financing,” Martikainen explains.
Operating near the shore at depths of 12-14 metres, where it captures surges while avoiding violent storms, WaveRoller consists of an 18x10-metre steel panel hinged to a base on the sea bed. The panel moves back and forth, feeding a power system which drives a generator. Electricity enters the grid through an undersea cable and a ground station. WaveRoller is emission-free and, as it is submerged, has a low visual impact.
“The device moves with the water and thus is not dangerous to animal life,” adds Martikainen.
Maintenance is relatively simple, with no need for diving operations. Tanks filled with air allow the device to be floated to its deployment location. They are then flooded with water to submerge the device, which can be re-floated by emptying them.
The WaveRoller demo project ended in 2014 making way for a 350-kW commercial installation on the same site in 2017.
Source: European Commission