Ecomare

In addition to turbines, there are number of other ways to generate tidal energy. It is important that the machines are very durable, since the force of the sea is tremendous. In 2004, a test with the Archimedes Wave Swing (AWS) finally began off the coast of Portugal, after three years of attempts to sink the prototype. The AWS is a kind of giant rusk tin, with a diameter of ten meters, developed by the Dutch company Teamwork Technology. The machine consists of two cylinders. The air inside forces the upper cylinder to move up and down under influence of the wave motions. It slides over the second cylinder, which stands on the sea floor. Magnets transform the movement into electricity. The machine is around 35 meters high and can produce two megawatts. Since September 2001, three attempts have been made to sink the prototype, but it only succeeded in 2004. If the experiment is successful, the producers want to construct an entire park with wave stations.
In 2002, the Wave Rotor was installed off the coast of Denmark, a kind of mixer turned inside out. Sea currents provide the necessary force to make the 'mixers' rotate, independent of the direction of the current, while the waves generate a vertical movement. The machine was developed and tested by the Utrecht advice bureau Ecofys and a Danish partner. It was supported by the Danish Wave Energy Program, which was later discontinued by the conservative Danish government. The Wave Dragon was also developed in Denmark. This is a kind of boat which is washed over by waves. The water runs back out via an outlet pipe containing a turbine. A first test sample was put into use in 2004.

Lastly, Scotland has developed an entirely different machine, called the Pelamis. This is a hinged snake 120 meters long, which floats on the waves. The movements between the hinges are converted into electricity, whereby 0.75 megawatt is produced.