Erhvervsbladet reports that on Wednesday 8 April, yet another Danish pilot scale wave energy machine will be placed in the waters of the Limfjord in northern Jutland, close to the little island of Venø. The company behind the initiative is called Dexa Wave Energy, whose 1:10 scale model has previously been under study in a test tank at nearby Aalborg University.
Dexa's wave machine is quite simple in concept, consisting of two rigid pontoons hinged down the middle so that the one can pivot in relation to the other, with a hydraulic power take-off system placed in between. The test machine to be installed in the Limfjord is a scaled step along the way to a full scale 250 kW model.
The floating pontoon design from Dexa is the fourth Danish wave machine concept to be tested, the others being Wave Dragon, Wave Star Energy and Floating Power Plant. Being a floating design, Dexa's concept is in principal best suited for deep water locations with their commensurately larger waves.
The energy in waves is affected by many more factors than the energy in wind. This explains why there are many more designs and technologies being explored compared with wind energy, which is essentially based on a single technology. It also explains why wave energy is a generally more slowly evolving renewable energy sector than the wind industry.
On the subject of pilot scale vs. full scale plants, readers may like to know that wind turbines and wave power machines do not share the same scalability factor. If you double the diameter of a wind turbine rotor, you get four times more power. But if you double the size of a wave power plant, you get 11 times more power.