The world’s first floating offshore wind farm, located roughly 25 kilometers off the coast of Peterhead, Scotland, powered up on October 18, delivering electricity to the Scottish grid.
Hywind Scotland was developed by Norwegian oil company Statoil based on the results of an eight-year demonstration project located off the shore of Karmøy, Norway. The new farm (Figure 5) consists of five 6-MW floating wind turbines covering about four square kilometers of water at depths between 95 meters and 129 meters. The farm has a total installed capacity of 30 MW. According to Statoil, the wind farm will power approximately 20,000 households.
Each turbine is 253 meters high, 78 meters of which are below the surface. The turbines have a rotor diameter of 154 meters with blades that are 75 meters long. Each turbine weighs about 12,000 tonnes and is secured to the sea floor with 15 suction anchors, each of which is connected to the turbine by 2,400-meter-long chains.
Statoil partnered with Masdar on the Hywind Scotland project, investing a combined $2 billion. Hywind Scotland’s price tag represents a 60% to 70% cost reduction from the Hywind Demo project.
The Hywind turbines are suitable for water up to 800 meters deep, opening up areas previously inaccessible for offshore wind. Conventional offshore wind turbines must be embedded in the sea floor, limiting their use to relatively shallow areas near shore. Areas with a narrow continental shelf, such as the West Coast of the U.S., are all but inaccessible to conventional offshore wind.
Advances in floating offshore wind, therefore, open up new, potentially lucrative markets to the offshore wind industry. According to Statoil’s floating offshore wind market outlook, key markets for Hywind technology are in Europe, Japan, and the U.S. West Coast. The company’s estimates show that the technical potential for floating wind power is 6,959 GW for Europe, the U.S., and Japan combined. Of high potential markets, Statoil believes Japan can have 3.5 GW installed by 2030, followed by 2.9 GW in France, 2 GW in the U.S., and 1.9 GW in Ireland/UK.
The outlook notes that not only would floating wind introduce a new product in places like the U.S. and Japan, but that there is an existing demand just waiting to be filled. “Here, floating installations could be a game changer, and the key to meeting renewables ambitions. For example, California has set a target of 50% renewable energy, while in Japan, the shift away from nuclear power will drive the need for new and reliable energy supplies,” the outlook says.
Statoil is already working to develop its next large-scale project, a full-scale floating wind farm that will likely be located in Ireland, France, off the U.S. West Coast, Japan, or possibly Norway.
Statoil predicts that floating offshore wind, though it is in its infancy, will see the same significant cost reductions that onshore and conventional offshore wind have seen in recent years.
—Abby L. Harvey is a POWER reporter.