Miliband backs Orsted in wind theft row with BP and EnBW
Energy secretary tells BP and EnBW to assess how wake losses from new offshore wind project will affect Orsted sites, although whether he will order mitigation or compensation remains to be seen
UK energy secretary Ed Miliband has sided with Orsted on a key issue in its wind theft row with BP and EnBW over a planned offshore wind farm in the Irish Sea, a decision with implications for numerous other disputes developers are fighting over wake losses.
Orsted is currently involved in several disputes with fellow offshore wind developers over wind wakes that could stretch from new planned UK projects to existing assets owned by the Danish developer.
One of those disputes is playing out in the planning proceedings for the twin 1.5GW Mona and Morgan offshore wind projects in the Irish Sea. Orsted has been demanding that the two projects assess how much wind they will ‘steal’ from its existing assets nearby.
German utility EnBW and UK oil giant BP, which are developing Mona and Morgan, have argued that the National Policy Statements (NPS) that guide decisions on such projects do not require them to carry out a wake loss assessment.
The planning proceeding for the Mona project concluded in January and the Examining Authority submitted its report and recommendation to the Labour government’s energy secretary, Ed Miliband.
In a Monday letter from the Department for Energy Security and Net Zero, Miliband said that the current NPS and the new NPS currently under consultation both “suggest that an assessment be carried out”.
What are wind wakes?
When wind turbines extract energy from the wind to produce power, they leave trails of lower intensity and more turbulent wind stretching behind them. These trails, known as wind wakes, can stretch vast distances – even 100km. If one wind farm is caught in the ‘shadow’ of another’s wake, the lower wind speed will mean it generates less power, reducing revenues. One wind farm 'waking' another is sometimes known as ‘wind theft’.
The two sets of NPS also suggest that “steps be taken to minimise impacts and that an applicant shows they have made reasonable efforts to work collaboratively with those who may be impacted,” said Miliband.
He requested that Mona provide, without prejudice, a proposal to secure a wake loss assessment – if, that is, it disagrees with the findings of another assessment already submitted by Orsted.
Mona should also consider “means to minimise any assessed impacts, including opportunities to work with impacted windfarms to achieve this,” said Miliband.
The only decision issued on this issue to date came in 2023, when a project being developed by RWE in the Irish Sea was ordered to carry out a wake loss assessment and mitigate any losses it caused to a neighbour. That decision was however taken by then-energy minister Claire Coutinho and it was unclear if Miliband would follow the nascent precedent set by his Conservative Party predecessor.
The wake loss assessment Orsted had submitted in the Mona proceeding was carried out by consultancy Wood Thilsted, which found that Mona, Morgan and two other wind farms planned nearby could cause wake losses of up to 5.3% at existing Orsted sites.
Orsted owns 1.85GW of operational offshore wind farms in the Irish Sea. They include West of Duddon Sands, Barrow, Walney and Burbo Bank. There are also major extensions for the latter two sites.
Orsted said that the scale of the wake losses its existing assets could suffer, which would reduce annual energy production by the same amount, threatens their continued existence, certainly in regard to lifetime extensions that could be considered.
Scott Urquhart, CEO of Danish offshore wind intelligence company Aegir Insights and a former Orsted project CFO, previously said that an AEP loss of much above 1% is “painful” for a project, while losses above 5% “could be catastrophic”.
While Miliband has sided with Orsted in ordering EnBW and BP to carry out a wake assessment, that does not mean, crucially, that he will side with the Danish developer in ultimately requiring mitigation or compensation for wake losses.