
Photo:WindFloat Atlantic.
Portugal’s WindFloat Atlantic – the world’s first semi-submersible floating offshore wind farm – is now four years old.
We keep learning that our innovations to save the environment often have unexpected effects, both positive and negative. That’s why more research is always necessary.
Studies of offshore windmills, for example, need to be expanded to include a new variety — one that floats.
Michelle Lewis writes at Electrek, “The 25 megawatt (MW) WindFloat Atlantic, which came online in July 2020, was also continental Europe’s first floating offshore wind farm. … WindFloat Atlantic’s electricity production has steadily increased, reaching 78 GWh [gigawatt hour] in 2022 and 80 GWh in 2023. In July 2024, it recorded a total cumulative production of 320 GWh, providing power annually to over 25,000 households in Viana do Castelo, north of Porto [Portugal] while preventing more than 33,000 tons of CO2 emissions and creating 1,500 direct and indirect jobs.
“The offshore wind farm sits 20 km [~12 miles] off the Portuguese coast. It comprises three 8.4 megawatt (MW) Vestas wind turbines that sit on semi-submersible, three-column floating platforms anchored by chains to the seabed. A 20 km-long (12.4-mile) cable connects it to an onshore substation.
“Here’s how the semi-submersible floating platform works:
- “Each triangular floating platform is semi-submersible and anchored to the seabed. It consists of 3 vertical columns, interconnected/solidary to each other, and one of them is attached the base of the wind turbine tower.
- “The lateral distance of the platform (between the center of the columns) is about 50m. Its stability is reinforced by a system of gates that are filled with water at the base of the three columns, associated with a static and dynamic ballast system.
- “This active ballast system moves the water between columns to compensate for the stresses caused by the wind thrust on the wind turbine. This moving ballast compensates for significant differences in wind speed and direction. Its purpose is to keep the wind turbine tower upright to optimize its performance.
“WindFloat Atlantic has an operations and maintenance base in the port of Viana do Castelo, where the team receives the wind farm’s information in real-time so they can address issues immediately. Onsite intervention can be complex, due to adverse weather and sea conditions in the area where it’s sited.
“At the end of 2023, WindFloat Atlantic was resilient in the face of Storm Ciarán, weathering wave heights of 20 meters (66 feet) and wind gusts up to 139 km/hr (86 mph).
“Ongoing surveys have found that over 270 species are successfully coexisting with WindFloat Atlantic, and the floating structures have fostered marine life, contributing to a conservation and reef effect underwater.” More at Electrek, here.
Of course, as we know, all offshore windmills have reef-making effects. And the mixed environmental impacts are the reason many conservationists have had mixed feelings about windmills. But now the benefits seem to outweigh the concerns.
Jared Brey wrote at Sierra Club magazine in 2022, “Historically, many environmental groups have worked to slow down the permitting process for development until possible impacts to wildlife have been studied. Today, the environmental consequences of not speeding up offshore wind development are arguably worse than delaying it. In August 2021, the most recent report from the Intergovernmental Panel on Climate Change (IPCC) emphasized how urgent the stakes are: Unless countries around the world cut their carbon emissions drastically in the next few years, climate change will devastate ecosystems around the world within our lifetimes. …
“[Environmental] groups will decide what research needs to be done and who will fund it, says Emily Shumchenia, director of the Regional Wildlife Science Entity. The group is making research plans for different topics; a marine mammal subcommittee held its first meeting in December, for example. Then it will begin researching existing wildlife and how it might be affected by offshore wind farms. ‘This is a huge opportunity to collect information about the ocean and learn about the ecosystems out there that we wouldn’t have otherwise,’ Shumchenia says.
“It’s important, Shumchenia adds, to push past the ‘data paralysis’ that sometimes delays decision-making, especially for something as critical as renewable energy. The government and offshore wind industry have a responsibility to understand how wind turbines will affect sea life. But the human footprint is already offshore, in everything from commercial fishing to shipping to anthropogenic climate change.
“ ‘I think there’s this perception that the ocean is this vast untapped wilderness, which in some ways it is — it’s vast,’ Shumchenia says. ‘But especially in the Northeast [US] and probably the entire Mid-Atlantic, it’s a lot busier than people perceive.’ ”
See Sierra Club, here.
