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Almost a quarter of a century later, offshore wind is one of our most important sources of green energy. Blyth Offshore Wind Farm is no more, however, after it was decommissioned in 2019.
That fate soon awaits many other early offshore wind farms unless swift action is taken, a new report has warned. The country risks losing five gigawatts (GW) of capacity by 2035, according to the report from trade organisation RenewableUK – equivalent to one-third of total offshore capacity.
The report, Developing Effective End-of-life Policy Frameworks for UK Offshore Wind, sets out proposals that could extend the operational lifespans of offshore wind farms, as well as recommendations for the best ways to decommission those that need it.
Facing extreme loads throughout their operation due to their size, structure and high winds, turbine blades degrade over time. Other components, including gearboxes and generators, also become worn out. The typical lifespan for turbines is 20-25 years.
“We have a great opportunity to strengthen the UK’s energy security by leveraging existing offshore wind infrastructure – either by extending the lifespan of existing projects or by repowering sites with modern state-of-the-art models. Instead of losing offshore wind capacity, we could potentially increase it,” said report co-author Nick Hibberd, policy manager at RenewableUK.
“With greater policy clarity on lifetime extension and repowering, we can ensure that the government achieves its climate targets by maximising our offshore wind capacity, which is the central pillar of our future clean energy system.”
The report calls on the government and regulators to clarify policies on extending the lifespan of offshore wind farms to get greater value from existing sites. Lifetime extension involves upgrading or overhauling existing machines and transmission assets.
It also urges them to develop measures for ‘repowering’ offshore wind farms, including exploring extending leases. This would build on “recent positive steps by the government” such as developing onshore wind repowering policies for upcoming auctions for new clean power projects, the body said.
Repowering involves replacing wind farm infrastructure with “new components of a significantly different scale and nature from what was consented to in the original project design,” the report said, such as new foundations or turbines.
“Policy attention is rightly focusing on building new offshore wind farms. However, with originally anticipated average lifespans of 20 to 25 years, the UK’s earliest offshore wind farms are currently entering their final lifespan stage,” said report co-author Friederike Andres, RenewableUK policy manager.
“Clear direction and leadership are needed from governments and regulators in developing the best possible decommissioning programme for offshore wind farms, taking full account of the complex technical, commercial and environmental factors involved, as well as enabling us to achieve the best outcomes for the marine biodiversity.”
The report also calls for clear direction and leadership on decommissioning, including updating existing guidance to “recognise the complexity of the task” and to take technical, commercial and environmental challenges into account.
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