Frisian company SeaQurrent recently started a test project for generating sustainable energy in the Wadden Sea. They are doing this with a kind of kite they developed themselves that uses underwater currents.
The kite, called TidalKite, uses tidal action, the current created by the alternation of ebb and flood. "Water them wind actually have the same properties, although water is much heavier," SeaQurrent's Youri Wentzel tells Omroep Friesland. "When water moves, there is a lot of kinetic energy in it. We capture that kinetic energy with the kite and convert it into sustainable electricity."
The kite
It is the TidalKit that does the heavy lifting underwater. Youri: "The kite pulls very hard. The final model we are going to develop pulls with 120,000 kilos. It pulls on a system and we eventually convert that pulling power into electricity. The pulling force is first converted into rotational force, this causes a generator to start turning and that generator generates electricity. There is a cable connected to a cylinder, the current fuels that cylinder, and that is how you generate energy."
The technology of the TidalKite is made to generate usable energy even at low currents, but more current is always better, Youri told Omroep Friesland. "With the TidalKite you can generate a lot of energy, but it depends on how much energy there is in the water. It's just like with wind: when it blows hard, the windmills give a lot of energy and when it doesn't blow they do nothing. It is the same with flowing water. In areas where it flows nicely, for example in the estuaries, on the mud flats, in Zealand or stretches of the North Sea, you can generate a lot of energy. One TidalKite kite system can generate around 500kW of energy. That is enough energy to supply 700 households with renewable electricity."
First worldwide
According to SeaQurrent, their TidalKite is the first truly useful technology to generate energy in water. "The sea is a huge source of energy, which is actually very little used at the moment. This is also because current technologies are actually not good enough. That is why we have developed this technology. Of course, it is a bit crazy to go kite flying under water, which is a special technology after all. But only with this technology is it possible to start providing reliable electricity as well as affordable electricity. That is a nice step that we will now take here on the mud flats in Friesland."
What eventually comes out of it remains to be seen. "It is and will remain an exciting experiment. It is the first technology we are developing like this worldwide, so our experiences are purely based on scientific research and tests we have done in laboratories. But now it is going to happen in real life. We have full confidence in it, but it is very exciting for sure."
Near Cornwerd, a TidalKite will be installed at two locations. If the test period goes well, perhaps more places in the sea will have these kites.
Source + photo: Omroep Friesland/SeaQurrent
