Wave Energy in the North Sea


The Slow Mill is a Wave Energy Converter consisting of a floater with blades variably connected to an anchor on the seabed. Waves push the floater up and the blades away from the anchor. This way not only the up and down movement but also the back and forth movement of the waves is utilised. The blades go as deep as 4-5 m to extract wave power from below the surface as well. When the wave recedes, it takes the Slow Mill back to its starting position and a winch reels in the cable, preparing the device for the next work stroke. The entire unit follows the orbital or sometimes elliptical wave path but moves a bit slower than the wave, hence its name: Slow Mill.

The floater can be entered via an air tight lock as inside the climate is controlled. The floater is kept under a constant over pressure of ca. 0,1 bar to prevent salt water or vapours to enter. This way the hydraulic and electric systems are protected and can be maintained in a controlled environment. If any leak might occur, it'll be instantly noticed by a pressure drop but water still can't enter due to the over pressure. The leaking air will be supplanted by a compressor until repairs are ffinished.