Wind power company SeaTwirl has obtained an approved concession for installation of the Company’s S2x floating wind turbine in Bokn Municipality, Norway. The approval marks an important milestone for the Company. SeaTwirl, together with Marin Energi Testsenter AS (MET), applied for a concession period of five years. The installation site for S2x is planned to be located in Boknafjorden, northeast of Lauplandsholmen.
The application pertains to the installation of a 1-MW S2x unit, a vertical-axis turbine with mooring system as well as cables for power transmission. S2x has a height of 55 metres above sea level, a depth of 80 metres under the surface and a turbine with a diameter of 50 metres. The facility is to be located approximately 700 metres off the coast, at a sea depth of up to 130 metres. The site intended for the installation of S2x was previously a fish farm. It is planned that S2x will be connected to an existing onshore transformer substation, and it has been confirmed that there is sufficient capacity in the transformer substation to handle the power generated. SeaTwirl has already reported that Haugaland Kraft will purchase the electricity produced.
Peter Laurits, CEO of SeaTwirl, had the following comments: “We are pleased to have received approval from NVE (the Norwegian Water Resources and Energy Directorate), as we have been waiting for the concession in Norway to be able to proceed with the work on the S2x project. While awaiting the approved concession, we have made good use of the time. Our team has focused its efforts to improve the design of the turbine to make it as efficient and optimal as possible, and to review and minimise potential risks.”
SeaTwirl’s wind turbines use a vertical-axis wind turbine with a tower connected to the sub-sea structure, consisting of a floating element and a keel. As the energy of the wind causes the turbine to rotate, the structure maintains its stability by using the keel and the counter turning moment, similar to the function of a keel on a sailboat. The wind turbine, the tower and the sub-sea part are assembled and rotate as one unit. Around the tower, above the water surface but below the wind turbine, is an enclosed, stored generator housing that is static or non-rotating. The generator housing and the wind turbine are anchored safely to the seabed by several catenary mooring lines.
SeaTwirl turbines can be sited in areas that are currently out of reach for offshore wind turbines (that are limited to a depth of about 50-60 metres). SeaTwirl turbines can be anchored much deeper than 50-60 metres (unlike any other wind offshore turbines on the market today). This means that SeaTwirl can be sited where winds are stronger and more reliable. Research and scientific reports also show that vertical-axis wind turbines have a high structural limit and can be built larger than horizontal-axis wind turbines.