In 2019, Floatgen — France’s only installed offshore wind turbine — generated a total of 6GWh, thanks to an availability rate of more than 94.6% in the second half of the year, when the 2MW demonstrator doubled its output, according to Ideol, which supplied the floating platform.
Despite some extreme weather, the turbine remained fully operational, producing power despite routine wave heights of 5.5 metres and wind speeds up to 24m/s at the test site off Le Croisic on France’s Atlantic coast. It has been online since September 2018.
Extreme weather
Floatgen is one of two offshore-wind demonstrators using Ideol’s technology, designed to cope with all kinds of weather.
The Hibiki floater in Japan, built with Japanese engineers Hitachi Zosen and operational since June 2018, has faced three typhoons.
"As far as the technique goes, there’s nothing more to prove," said Ideol CEO Paul de la Guérivière.
"Floatgen has been tested in all kinds of conditions.
"This year in France, we saw particularly stormy weather, with waves over 12 metres, which shows that the floaters can withstand all types of conditions very well."
Floatgen is equipped with a Vestas V80 2MW turbine, which rests on a square concrete "barge" with a central opening — Ideol’s patented "damping pool" design — to counter swell and increase the foundation and turbine’s stability.
"The ‘damping pool’ means we can have a very dense floater that is very stable," de la Guérivière explained.
"This floater is simpler and more economical, as a standard barge moves too much."
Ideol’s foundations have a 7-10-metre draught and dimensions of 35 to 55 metres, which is smaller than other floating foundations.
Floatgen has a cement-based foundation, which is cheaper to manufacture in France, while the Hibiki project uses steel.
The foundations are assembled quayside and then towed out to sea, to cut costs and use local skills as much as possible.
The pilot project off Le Croisic met with no particular problems, largely thanks to the accuracy of Ideol’s simulations, according to de la Guérivière.
"Our big surprise with Floatgen is that we’ve had no surprises. Our simulators were extremely precise," he said.
Next moves
With the soundness of Ideol’s two demonstrators now confirmed, the company says it is ready for commercial deployment.
"For a long time, the offshore floating industry was in a development stage, but 2020 marks a major shift in the market. All the uncertainties over floating offshore have now been lifted," de la Guérivière said.
"We are looking at California, South Korea and France, and we have projects in Japan and Scotland," he added.
In Japan, Ideol is working with Japanese renewables developer Shizen Energy on the country’s first commercial-scale floating project off Kyushu, the country’s southernmost island.
A few months ago, the company teamed up with Belgium-based Elicio to develop floating wind projects in Scottish waters and is preparing to bid in the upcoming ScotWind leasing round.
The Crown Estate Scotland is expected to launch the tender once the Scottish government has finalised its Sectoral Marine Plan for Offshore Wind Energy, currently under consultation.
Closer to home, Ideol has been selected to equip the Mediterranean’s first floating offshore wind farm off Gruissan, in a consortium with French developer Quadran.
Indeed, Emmanuel Macron’s announcement in December, when the president promised an extra 1GW per year until 2024, seemed to indicate the tide was changing in France in favour of the industry.
De la Guérivière remains sceptical, however. Out of six offshore wind projects awarded in France in 2012 and 2014, only one, at Saint-Nazaire, has started work.
"The government has said that floating is a priority. But the reality isn’t in line with this," he said.
"In France, there is a real disconnect between the country’s ambitions and what actually happens on the ground."
