Wind farms are built to catch wind. But what happens when one wind farm is large enough to rob the wind from another?
That question moved from theoretical to regulatory on May 14, when the UK government approved Dogger Bank South — a 3GW offshore project that would rank among Britain’s largest wind farms. The approval came with an unusual condition attached, one that reflects a growing tension in the crowded North Sea, where dozens of offshore wind projects now compete for the same moving air.
A crowded sea and a 3GW giant
Dogger Bank South is a joint venture between German utility RWE, which holds a 51% stake, and UAE state-owned renewables firm Masdar, which holds the remaining 49%. The project comprises two 1.5GW offshore wind farms, giving it a combined capacity of 3GW — enough to place it among the largest offshore wind developments in the UK pipeline.
The development consent order, described by law firm Norton Rose Fulbright as the primary and ultimate permitting approval needed to construct and operate an offshore wind farm, was granted on May 14. The decision came after the government had twice pushed back its own deadline, missing targets set for both January and April.
Both RWE and Masdar had already secured contracts for difference for the two wind farms in the UK’s AR7 renewable energy auction in January, giving the project a revenue foundation before the planning hurdle was cleared. The UK currently operates 16.9GW of offshore wind capacity, according to Windpower Intelligence. A 3GW addition would represent a meaningful expansion — though it won’t arrive quickly. RWE says a final investment decision is targeted for 2027, with detailed design work and procurement decisions still ahead.
What the wake effect actually means
Wind turbines work by extracting kinetic energy from moving air. That extraction has a consequence: the air passing through a turbine’s rotor emerges slower and more turbulent on the other side, creating what engineers call a “wake.” For a single turbine, this matters mainly for spacing decisions within the same farm. In a dense offshore environment like the North Sea, however, the effect can extend well across project boundaries.
When one wind farm’s wake reaches a neighboring project, that project’s turbines encounter lower wind speeds than they’d otherwise see — which means less power output and less revenue. The larger the upstream wind farm, the more pronounced the potential impact.
This isn’t a fringe engineering concern. As the North Sea fills with ever-larger offshore wind projects positioned in relatively close proximity, wake interference is becoming a structural challenge for the industry. At 3GW, Dogger Bank South is large enough that its downstream footprint could affect several neighboring developments at once.
The government’s unusual condition
Energy Secretary Ed Miliband approved the project but attached a condition that has few clear precedents in UK offshore wind regulation. In a letter to the Dogger Bank South developers, Miliband required RWE and Masdar to “secure appropriate consultation and mitigation prior to construction through a wake effects plan.”
That plan must address consultation with operators of neighboring projects likely to be affected, allow flexibility for private agreements between developers, and provide clarity on implementation and timescales. Construction cannot begin until the plan is in place.
The requirement is notable because it forces a clean energy approval to formally acknowledge that one renewable project could cause measurable harm to others — a tension regulators have rarely had to confront directly. Separately, the Ministry of Defence, which had previously opposed parts of the Dogger Bank South development over potential radar interference, dropped its objection after those issues were resolved through a different process.
Neighbors watching closely
Ørsted, the Danish energy company that operates the Hornsea wind farm cluster in the North Sea, had raised formal concerns during the planning process. According to recently filed planning documents, Ørsted argued that Dogger Bank South’s wake effect could disrupt wind speeds at its Hornsea projects, leading to financial losses. Following the approval, an Ørsted spokesperson offered a measured response: “We look forward to discussions with the developers of Dogger Bank South as the project progresses.”
That statement signals ongoing concern rather than resolution. Discussions haven’t happened yet. The wake effects plan hasn’t been written.
On the same day Dogger Bank South received its approval, the government also granted a development consent order for North Falls — a 1GW project developed by RWE and SSE as an extension to the existing 504MW Greater Gabbard offshore wind farm off England’s east coast. North Falls hasn’t yet secured a contract for difference, leaving its financial future uncertain. Its approval nonetheless adds further density to an already crowded stretch of water, and it sharpens a question the industry hasn’t cleanly answered: when one offshore wind project measurably reduces another’s output, who bears the cost?
What comes next for Dogger Bank South
RWE and Masdar will now move into detailed final design work and begin making procurement decisions. With a final investment decision not expected until 2027, construction remains years away — which means there’s time, at least in theory, for the wake effects plan to be developed thoughtfully rather than under pressure.
The mandatory consultation process with affected neighbors will be the first real test of whether the industry can resolve resource-sharing conflicts through structured dialogue before they escalate into financial disputes or legal challenges. If the wake effects plan process works — producing agreements that fairly allocate mitigation responsibilities — it could become a template for future approvals in similarly crowded waters. If it stalls or collapses into disagreement, regulators may face pressure to develop binding rules rather than relying on developer negotiation.
Either way, Dogger Bank South has made one thing clear: the North Sea is no longer big enough to treat each wind farm as an island.