Cost cuts vital for buoyant floating sector

Companies in Europe and Asia are proving that floating wind farms are possible — but the economics of floating wind suggest this part of the sector is still more likely to sink rather than swim.

This month, Norwegian utility Statoil committed to invest £150m in the first floating offshore wind farm in UK waters, the 30MW Hywind 2, also known as Buchan Deep. This project is the follow-up to Hywind 1, which the utility completed in the waters off the coast of Norway in 2009, and Statoil says the new scheme is a big leap forward in terms of technology too. It says that energy at Buchan Deep is set to cost 70% less to produce than at Hywind 1.

Developers are becoming more ambitious in the technology they use in floating projects.

In Japan, a Marubeni-led group installed the world’s largest floating turbine, measuring 7MW, in June in a testing zone off the coast of Fukushima. Japan sees floating wind as key to its move away from nuclear power following the Fukushima-Daiichi disaster of 2011.

But we heard in a session at the EWEA conference in Paris last week that floating offshore wind is a long way from being to compete on cost against schemes with fixed foundations.

Cian Conroy, business development manager at the UK’s Offshore Renewable Catapult said that the cost of a commercial floating wind farm would currently equate to a levelized cost of energy of around £193MWh, compared with around £120/MWh for a development with fixed foundations. He added that floating wind would need to get close to £85/MWh in the 2020s — or more than halve in price — if there is to be major growth in the sector.

In other words, we will see investment into this sector from those wanting to innovate and bring down the cost of floating technology, but projects of interest to external investors are still a long way off. This is likely to take ten years or more, if it happens at all.

The session also included ideas for how to cut the levelized cost of energy, including from floating technology innovators including Henrik Stiesdal, Siemens’s former chief technology officer.

Stiesdal is now designing innovations including a floating turbine platform called In-Float. He said those in floating wind should look to onshore wind for inspiration on cutting costs, with approaches such as off-site manufacturing and standardised designs.

Stiesdal said that onshore turbine manufacturers did not have much intellectual property of any significance, and so had been forced to compete on who can do turbine installations fastest and cheapest. This has driven down costs in the sector. Standardised designs for floating foundations would enable manufacturers to compete on similar terms.

“I am concerned that if we [in floating wind] do not do things in a different way then we will be confined to demonstrations and pilot projects, and things will fizzle out,” he said.

Meanwhile Tomofumi Fukuda, general manager for domestic power at Marubeni, said the Marubeni-led Fukushima Forward consortium has so far developed its offshore zone using backing from the Japanese government, but its focus is now on commercialising the technology: “Our next project has to be purely on a commercial basis,” he said.

Firms now have the technology to make floating wind possible, but the costs of using this technology need to fall steeply if the sector is to keep its head above water in the next decade.