For his doctoral project at Uppsala University, Rafael Waters, has designed and built a wave power facility on the bottom of the sea, two kilometers off the west coast of Sweden, near Lysekil.
Electricity is produced using a linear generator that works with the slow movements of the waves. A conventional generator transforms rotational energy to electricity and it needs to turn at about 1500 rpm to be efficient – which means that the slow wave movement needs complicated gears of hydraulics to convert it into a rapid rotating movement.
“Instead of trying to adapt conventional energy technology to the special challenges of wave energy, we developed a technology that is adapted to the ocean from the start,” says Rafael Waters. “Our generator has functioned without any trouble every time we started it up over the years, even though it has received no maintenance and has sometimes stood still for months.”
Next year the wave power facility in Lysekil will be complemented by two more plants and connected to one of the world’s first wave energy parks which will eventually include ten plants.
The researchers estimate that wave energy should be able to supply Sweden with about 10TWh of electricity per year, comparable to 12 nuclear power plants – but Raphael Waters points out that many other countries have much more wave energy potential than Sweden.