The Windfloat Atlantic project stands as the planet’s first floating offshore wind farm, located off the coast near Viana do Castelo in northern Portugal. Backed by a collaboration between Portugal’s energy company PDEnow and French expertise in offshore wind, the facility marked three years of continuous operation at full capacity this month. Ocean Winds, the joint venture between EDPR and Engie, continues to explore additional deployment opportunities in the Iberian Peninsula and beyond, including plans that could take shape in Galicia.
The Windfloat Atlantic complex began generating electricity in December 2019. The first tower, built by Ferrol windar and Navantia, was installed about 18 kilometers from the coast. Over the following months, the remaining two platforms were completed, with one located near Setúbal, Portugal. Since then, the project has evolved into a notable milestone for floating wind technology, demonstrating a viable path to offshore wind power beyond traditional fixed-bottom structures.
Three years after installation, the three-turbine ensemble sits roughly 20 kilometers offshore, spanning about 11 square kilometers. Its production has met expectations for performance and reliability, and the arrangement has been shown to coexist with other marine uses, including biodiversity protection and fishing activities, according to its promoters.
With a total installed capacity of 25 megawatts, the three wind turbines together meet the annual needs of tens of thousands of homes. The Windfloat project is owned by the Windplus consortium, led by Ocean Winds, a joint venture of EDP Renewables and Engie’s renewable-energy affiliate. The consortium also includes the Spanish energy company Repsol and Policy Power, a U.S. technology provider.
The Viana do Castelo complex represents the first commercial deployment of semi-submerged offshore wind power following an earlier offshore pilot project that ran between 2011 and 2016. That earlier effort took place about 40 kilometers south of Viana do Castelo and involved a 2-megawatt turbine. The transition from pilot to commercial scale confirmed that floating turbines can access wind resources far deeper than those reachable by fixed-bottom installations and can endure challenging marine conditions, including extreme wave heights. Although floating wind remains more expensive than onshore or fixed offshore wind, the experience gained here has established a credible pathway for future profitability and industrial growth.
Projects
Industry observers widely expect floating offshore wind to outpace fixed-bottom offshore wind in many regions. The main reason is the narrowness of continental shelves in numerous coastal areas, including parts of the Iberian Peninsula and Galicia, which makes fixed structures impractical in deep water close to shore.
Ocean Winds currently operates another floating facility in the southern French coast near the Bay of Biscay, while a separate fixed-bottom project exists in Scotland. A mixed (fixed and floating) project is also underway in Scotland. The company is actively supporting two major developments in engineering and planning in South Korea and California, with capacities of 1,300 megawatts and 2,000 megawatts respectively. Although several Galicia projects have surfaced recently, some progress has stalled amid regulatory uncertainties. Until clear policies emerge, marine area management plans and capacity allocation tenders continue to shape the pace of development. The sector is watching for ongoing technological advances that could unlock even larger, more powerful turbines in the near future.
Floating offshore wind towers present a striking image: three towering platforms rise offshore, about 35 minutes by boat from Viana do Castelo. The blades, sweeping through the wind, generate electricity with almost no noise beyond the ship’s engine and the sea itself. Dolphins often approach, drawn by the activity, while seabirds skim above. Each semi-submerged turbine sits on a platform rising up to 30 meters above the water, with portions remaining below the sea surface for stability. The towers are anchored to the seafloor at depths around 100 meters, using a chain system that holds the structure in place. Platforms are spaced about 600 meters apart to reduce interference. The blades measure 82 meters in length and 164 meters in diameter, delivering up to 8.4 megawatts of power per turbine. The design anticipates winds up to 100 kilometers per hour and waves as high as 20 meters. In the previous year, the project produced approximately 78 gigawatt-hours of electricity, underscoring its role as a growing component of a diverse energy mix. The ongoing focus remains on strengthening resilience and expanding capacity as the technology matures.