French energy giant Engie said floating wind is ready for gigawatt-scale deployment – but differed with fellow developer EnBW over whether the sector can fully match fixed-bottom deployments on cost.

Grzegorz Gorski, Engie’s offshore wind managing director, said floating turbines can make the leap to mass deployment, aided by the entry of oil and gas sector players such as Saipem to the sector.

“It’s very good that oil and gas companies, and oil and gas service companies [are coming into floating wind],” he told the BNEF Summit in London.

“They know their stuff, they’ve been doing this for many years, they are no longer start-ups,” said Gorski.

Engie is a keen early backer of floating wind projects, including the pioneering WindFloat Atlantic deployment off Portugal in which it holds 25%.

France is preparing to hold three tenders for 250MW projects, but has said these could triple in size to 750MW if the industry can make a case. Several early-stage gigawatt-scale projects have been announced in Asia.

Gorski said scale is a prerequisite to achieve the big cost reductions needed for the sector to become competitive. “If you really want to have a low tariff, then size is the answer,” he told the panel.

The Engie executive said he is confident floating will become comparable with fixed-foundation deployments. “Floating will get to the same cost.”

When that happens Gorski said the choice will be one of the right technology for water depths – with floating preferred to monopile foundations beyond 60 metres.

However, Hannah Konig, head of wind and maritime technology at EnBW, another developer active in floating wind, was less certain it would achieve parity. “I’m completely confident from a technology point of view that if we piece it all together it will work. The question is at what cost,” she told the BNEF Summit.

Konig said a slight premium over fixed would still leave floating in a good position, given its ability to deploy in waters inaccessible to other alternatives.

From an LCOE point of view, it might always be a bit more expensive.

She said: “Personally I think from a [levelised cost of energy] point of view it might always be a bit more expensive. But if it’s the only resource you have available you will still do it, because it will eventually still be cheaper than fossils.”

Julian Brown, UK country manager for MHI Vestas, whose 8.3MW turbines sit atop the WindFloat Atlantic turbines, said floating wind still has questions to answer over its ability to gear-up its manufacturing supply supply chain for cost-effective mass deployment, but added: “Once those problems are cracked – the rate of deployment, fabrication, tooling up for manufacturing, this is really going to go.”

Eoghan Quinn, global wind director at international energy contracting giant Worley, cautioned that the sector may need to learn more lessons before it can make a decisive leap to large-scale deployment, giving the example of some of his own organisation’s work on applying improved predictive maintenance to floating wind. “Let’s get to know the technology, let’s refine it down,” he said.

Forecasts for floating wind’s cost and volume pathway vary.

A study from Scotland’s University of Strathclyde released this month suggested 4.3GW – rather than the 12-15GW forecast by a range of analysts and developers – is likely to be switched-on by 2030.