It’s not uncommon to hear predictions that renewable energy’s next big leap forward will come with a boom in floating generation – but Børge Bjørneklett is convinced that it will be led by solar modules, not wind turbines.

As CEO of Norwegian floating PV pioneer Ocean Sun, Bjørneklett's bullishness over the technology’s prospects is hardly surprising, but he insists the data backs him up when he claims the fledgling sector is on the cusp of a boom that could outstrip even the growth tipped for foundation-free wind turbines.

“The application area is so much larger [than for floating wind] if you look at irradiation maps of the world, particularly in Southeast Asia,” he tells Recharge. “It’s also much more lean [in materials and deployment]”.

The application area is so much larger… if you look at irradiation maps of the world.

And while floating wind “still has a long way to go on cost”, Bjørneklett claims floating PV, and in particular Ocean Sun’s patented 'flotation ring' polymer membrane technology, is already “in many areas the most affordable source of energy”.

Floating wind’s many advocates may take issue with his analysis, but Ocean Sun – which is working with the likes of Statkraft and Fred Olsen Renewables, and says it is in discussions over more than 3GW of deployments – made a powerful statement of intent in February, when it hired Nenad Keseric as its new chief operating officer from Equinor.

Keseric spent more than a decade helping the Norwegian energy giant carve out a leading position in floating wind, and Bjørneklett claims his new hire is well-placed to help take Ocean Sun “to the next level” towards gigawatt-scale deployments around the world.

Ocean Sun is far from the only player in the fast-emerging floating solar market, which in recent years has been dominated by China’s Sungrow and France’s Ciel & Terre, both pioneers in the market.

But the Oslo-listed Norwegian group’s differentiator rests with its use of hydro-elastic membranes with mooring systems based on fish farming, rather than the rigid pontoons or floats more usually employed to place PV modules on lakes, reservoirs or even the open sea.

Water cooler moment

That allows highly efficient dissipation of heat into the surface below, effectively meaning the system is cooled by water, rather than air, which in Bjørneklett’s phrase has a “very interesting effect” on energy yield of around 0.4% per degree-centigrade, that can result in an increase of up to 10% compared to pontoons or ground-mounted panels.

The advantages of membrane deployment over pontoons does not stop at energy yield, according to Bjørneklett, with Capex reduced by the use of polymer materials around the perimeter of the membranes.

Ocean Sun’s 600kW circular membranes need up to 15-times less container volume to be transported than rival systems, he claims, and can be “unpacked like a big pancake” for the addition of modules, in the case of which are supplied by China’s GCL System.

Asked to put a cost-of-energy figure on its system, Bjørneklett says that depends heavily on irradiation levels and the size of system. “But we can now deploy systems for well under $500,000 per megawatt,” with the gap on ground-mounted systems narrowing fast, he claims.

The technology has also shown it can survive harsh weather conditions, with a prototype in the Philippines – one of three pilots worldwide – coming through tropical storms and monsoons.

Ocean Sun’s business model is as a licensor of technology, and the company, founded in 2016, is working with several big names in the energy sector as they advance their own ambitions.

Perhaps most strikingly, Ocean Sun is part of a project to build a 2.1GW floating PV plant on the Saemangeum tidal flat on the Yellow Sea coast of South Korea that is among the largest planned globally.

A 2MW project in Albania led by Statkraft is currently awaiting delivery of its modules, and

earlier in 2021 Ocean Sun announced it would link with Fred Olsen Renewables and others for a 250kW pilot deployment off the Canary Islands, as part of the EU’s Horizon 2020 programme.

The Canary Islands project, Bjørneklett explains, will test how Ocean Sun’s systems perform in less sheltered open-water conditions, which present the greatest challenges to floating solar systems.

Asian opportunity

But the firm’s CEO expects the vast majority of opportunities globally to come in coastal or sheltered areas, or inland waters, with Asia offering particular promise.

With onshore renewables often facing limited land availability, the region’s coastal megacities will look offshore for their power, Bjørneklett predicted, claiming floating solar has a big card up its sleeve compared to wind at sea.

“It’s flat, can sit a few kilometres away from big cities and you can’t even see it,” he says.

Bjørneklett concedes that the technology works best “between the 45th parallels” – so roughly below southern France in Europe and northern Japan in Asia – as “if you go too far north and south we suffer a bit on panel inclination”.

Even so, according to Bjørneklett, such is the potential for floating solar that it is not just floating wind that is in its sights – even onshore PV should start looking over its shoulder.

“I think to be a bit futuristic, people will ask themselves why they put up solar panels on land at all,” he says.

Bjørneklett’s prediction of global supremacy may be too rich for some, given that floating solar currently has only around 3GW operational around the world, a tiny fraction of the total renewables fleet.

However, there are plenty of objective observers willing to predict floating solar will have a big role to play.

Fitch Solutions said late last year it sees potential for 10GW of additions as soon as 2025, while DNV GL – which in 2020 established a joint industry partnership for the sector – has cited estimates that deploying panels on inland man-made waters alone has a potential to add four terawatts of power capacity worldwide.

Technology

'People will wonder why they put solar on land at all': pioneer says floating PV can beat wind