A historic day in the use of the sea to produce electricity. This is the assessment that engineers, businessmen and institutional leaders have made of the start-up of the Demosath floating offshore wind platform, the first prototype to be connected to the grid in Spain and which opens the way to a new technology.
The great depth of the offshore platform off the Spanish coast makes it unfeasible to use wind turbines with fixed foundations in the sea, the usual method used in large shallow continental platforms and installed in 90% of wind farms.
This Monday, two miles off the coast of Armintza (Bizkaia), the Demosath project was launched, on which the Basque engineering company Saitec has been working for 11 years and which still has another years of operating period ahead of it. During this time, while producing electricity, it will be testing the interaction of the wind turbine with the environment, from the prevention of collisions with birds and bats to its effects on fishing resources.
Saitec has launched the prototype in partnership with RWE and Japan's Kepco (Kansai Electric Power).
Clarity in the regulatory and remuneration framework
At the presentation ceremony - which had to be held on land due to weather conditions in Bizkaia on Monday - the business leaders expressed their fears about the "financial bumps" facing offshore wind, especially the small and medium-sized farms that are of no interest to large energy companies.
Saitec's CEO, Javier Urgoti, and RWE's head of floating wind power in Spain, Mikel Garay, have called on the government for "visibility" in auction calendars and locations. "Investors and the entire supply chain have to get organized, and we need time," they insisted.
Saitec Offshore's operations director, David Carrascosa, has been more direct: "A regulatory and remuneration framework is needed".
The government's plans are to reach an offshore wind production of three gigawatts in 2030. But, seven years ahead, companies have to carry out studies and decide on projects; and to do so they need to eliminate uncertainties, say the businessmen, who are calling for tenders to begin, as has already happened in the United States and is going to happen in Australia.
Fixed anchoring, which rotates according to the wind
The SATH (Swinging Around Twin Hull) technology consists of a double-hulled barge with two cylindrical prefabricated modular concrete floats.
The prototype has a floating concrete foundation 30 meters wide and 67 meters long, on which is placed the 2 megawatt wind turbine, whose axis rises 75 meters above the sea surface.
It has hybrid anchoring lines composed of chains and synthetic fibers, which are anchored to the seabed. This anchoring allows a fixed position, but with the capacity to rotate to face the wind.