Wave power

waves overtopping a test wave generator of the so-called Wave Dragon in Nissum-Bedding, Denmark

Wave power is a method of electrical generation, where energy from waves moving in water is transferred into an electrical current; the electricity thus produced is coined as renewable energy.

Wave power generation is not a widely employed technology with only a few experimental sites in existence. Wave power has however an advantage in comparition with many other renewable energy sources, because of its stability in production. Where for instance the amount of wind power being produced relies heavily on how strong winds there are locally, which fluctuates heavily from day to day and from season to season, the amount of wave power being produced wouldn't fluctuate so heavily, since the amount of energy stored in waves is more constant, and not so heavily dependent on the local weather conditions.

The problems sketched is one of the heaviest barriers in making an entire area dependent on renewable energy, for instance in a country like Denmark where approximately 20% of the power being produced originates from windmills, when the wind is strong, however over 100% of the consumption of the danish energy grid is being produced by windmills, and the surplus is being sold to other nearby countries, such as Sweden and Germany at a low price (since these countries also have a high production of wind and river energy at windy times in Denmark), when there is no wind, Denmark has to buy power from its neighbouring countries at a much higher price. These conditions make wind power less profitable, and many experts are of the opinion that Denmark has reached its maximal percentage of wind power being generated, unless some sort of storage of energy can be used. Wave power could, when fully developed, be another key for expanding the amount of renewable energy being produced, because of its much more stable production.

Many different system designs are currently being developed.

In one system, floating blocks are driven by wave action to push or pull a generator lying in the water. Water pushing through tubes will push a turbine which drives the generator.
With another method, wave action compresses air in a tunnel which drives the vanes of the generator. The bigger the difference between wave top and wave valley, the more power potential there is.
In yet another design, the overtopping of the waves are being led to a reservoir, the water, being pulled downwards through a tube by gravity, drives a generator.