An old fishing trawler has been given another shot in Norway, where it resides anchored offshore in the area of Stadthavet and plays the role of a wave power plant. It is the product of a project which aims for larger, purpose-built vessels to transform wave motion into useful electricity.

Norway's Kvernevik Engineering AS leads the project, even though the primary concept for the first fishing boat conversion belongs to Geir Arne Solheim, who is the founder of wave power company (and joint-project partner) Havkraft AS.

fishing boat power plant

Image: Kvernevik Engineering AS/ Facebook

The ship in question, Havkraft, uses an existing system better known as the "fluctuating water column" concept. Basically there are four vertical chambers that are installed in the vessel’s bow, which the surrounding sea water can easily flow in and out of. Each of the chambes is capped by a connected turbine, that is located on the deck of the boat.

As the waves hit the ship, they go right into the chambers and thus cause the water level inside each chamber to go up. This on the other hand causes a chain reaction as the air pressure in the chamber’s top part begins to increase, and thus drives the turbine which generates electricity. This method is also applied when the water flows back out of each respectful chamber as the lowered air pressure sucks air in through the turbine which again causes it to spin and generate electrical power.

The effect of the inward as well as of the outward flow of water is accentuated actually by the vessel itself, as it pitches up and down in the waves. A special anchoring system was designed that makes sure the boat is facing into the oncoming waves at all times.

According to several computer generated models which were created by project partner Marintek, the fishing boat should manage to produce aproximately 320,000 kWh annually. Kvernevik’s next plans revolve around the installion of a hydrogen production plant aboard the boat, so that the produced electricity can be successfully stored in the form of hydrogen gas that will be suitable for use in fuel cell vehicles.

The project partners then have hopes to construct a 5-chamber 1,000-kW plant, via the use of a bigger existing vessel or a purpose-built barge. In the end what they would like to see is a semi-submersible vessel that will have a 4-megawatt wave power plant to go along with a 6-MW wind turbine on top of it.