Offshore wind firms up the ante in Europe
No longer a niche sector restricted to north-west Europe, offshore wind is likely to play a significant role in meeting the world's clean energy needs
Offshore wind used to be portrayed as the costly renewable energy option that only got developed if onshore wind was too difficult to build or sell to the public. But, with the industry sinking money into pioneering and ever more efficient technology, the sector is increasingly well positioned to stand on its own two feet — even as subsidies are stripped away.
The latest headline grabber is GE's 12-megawatt Haliade-X offshore turbine, which will be the world's largest when it comes to the market. GE said it would invest more than $400m over the next three-to-five years to develop and deploy the technology.
The top of the turbine will be a maximum 260 meters above the sea, while the blades will be 107 metres long, making them the longest offshore blades to be produced. While size isn't everything, bigger turbines should create economies of scale and will mean less of them need to be installed for any given power requirement, saving costs on construction and infrastructure.
GE claims that the Haliade-X will have a 63% gross capacity factor—the amount of power actually generated as a percentage of maximum output—and will each produce 45% more energy than offshore turbines available today. Based on those figures, one turbine could generate up to 67 gigawatt-hours a year, enough to power 16,000 European households, GE says.
Jérôme Pécresse, chief executive GE Renewable Energy said on announcing the turbine's start up: "The renewables industry took more than 20 years to install the first 17 gigawatts of offshore wind. Today, the industry forecasts that it will install more than 90 gigawatts over the next 12 years. This is being driven by the lower cost of electricity from scale and technology."
There is no longer any need to rely on having shallow seabeds to erect turbines—something which has helped give European countries bordering the North Sea an edge in offshore development. Norway's Statoil has adapted its knowledge of floating oil rig technology to pioneer floating offshore wind farms, opening the Hywind Scotland project late last year, some 25km of Scotland's northeast coast.
By enabling wind turbines to be positioned further out to sea and in the windiest spots, regardless of sea depth, floating technology has obvious benefits if costs can be kept down. Statoil said output from Hywind, in which the UAE's Masdar is a partner, has exceeded expectations across the windy winter months.
The six-turbine demonstration project produces a modest 30MW at present, but recorded an average capacity factor of around 65% during November, December and January. Statoil notes that the typical capacity factor for a bottom fixed offshore wind farm in winter, when winds are strongest, is 45-60%. The facility also coped with winds of more than 160km per hour and waves of up to 8.2 metres in height.
The Norwegian firm says that with perhaps as much as 80% of the world's offshore wind resources located in water deeper than 60 metres—too deep for bottom-fixed turbines—it believes the technology has considerable potential. The hope is that the cost of energy production from Hywind could be cut to €40-60 ($49- $74) /MWh by 2030, a level which would be similar to the cost of other renewable energy sources at present, Statoil says.
Three other demonstration floating wind projects off Scotland are at an advanced planning stage, drawing in total investment of more than £400m ($555m). But the industry has warned that the early removal of key financial support from the UK government could jeopardise their progress and thus threaten pioneering work.
One turbine alone could generate up to 67 gigawatt-hours (GWh) a year, enough to power 16,000 European households.
For floating windfarms to be eligible for subsidies through the UK's renewables obligation (RO) scheme, which is being wound down, they must be generating power by October. However, two of them—Dutch firm 2-B Energy's 60MW Forthwind and Swedish company Hexicon's 10MW Dounreay Tri—look unlikely to meet the deadline. That has prompted industry body RenewableUK to request that the government deadline for RO support for these projects be extended to April 2020 to ensure they go ahead.
The projects may be small, but the stakes are high, given the sector's growth potential, as countries seek to meet growing power demand—including that from the electric vehicle sector—through clean energy rather than fossil fuels.
The latest forecasts from consultancy Douglas Westwood suggest that offshore wind capacity will rise by 20% a year between 2018 and 2027, from 22GW to over 112GW. That is expected to generate cumulative capital expenditure of more than €460bn and result in the construction of some 15,300 turbines. Over 60% of capacity add-ons in this period are expected to be developed in the existing hotspots of the UK, China, and Germany, with the Netherlands and the US also remaining strong in the sector.
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