Lidar links North Sea wake losses to turbines 34-mile upwind

Estimated reading time: 6 minutes · Last updated: 31 August 2026

As first reported by Energies Media, a scanning lidar installed on a 400 MW North Sea platform mapped slower, thinner air arriving at the farm and traced it back to other operators’ turbines 16 and 34 miles upwind. The instrument returned cross-sea scans that matched satellite radar and the farm’s own power logs: in lidar snapshots the nearer cluster produced a peak wind-speed deficit of 40.5% (24.7% averaged over the scan) and the farther cluster produced a 26.4% deficit. These measurements show how offshore wind wakes can travel tens of miles and cut rotor input long before a downwind farm’s own turbines encounter full-speed wind. The primary keyword is offshore wind wakes.

How a scanning lidar mapped wakes across open sea

A scanning Doppler lidar samples wind across a broad arc rather than measuring a single point at one height like a fixed met mast. Installed on the 400 MW platform and aimed toward the horizon, the unit swept cross-sections of wind speed out to tens of miles. On certain days those scans revealed a distinct river of slower air that traced back toward the clusters upwind of the farm. Satellite radar imagery from the same days reproduced the banded wake pattern, and the farm’s control system recorded matching power drops beneath those bands. Together, the datasets link reduced output at the farm directly to the distant clusters rather than to a local fault or a forecasting error.

Because the lidar measures profiles across distance and angle, it can locate the wake corridor and quantify the speed deficit at the heights the scans reached. That gives operators a spatial picture of how a wake from a separate concession crosses a lease boundary and intersects rotor swept areas, information a single-point met mast cannot deliver.

Measured scale: the clusters, the deficits and the studies

Two upwind clusters left the clearest mark on the lidar scans. One cluster sits about 16 miles to the southwest and totals 802 megawatts of turbines; the other is about 34 miles to the southeast and totals 914 megawatts. In one lidar campaign the nearer cluster produced a peak wind-speed deficit of 40.5% in the scanned corridor and 24.7% when averaged across the full field of view; the farther cluster produced a 26.4% deficit in the same campaign.

Those lidar measurements came from a campaign run in the summer of 2018; the campaign’s authors published their analysis in a wind-energy journal in 2020. A separate satellite study, published in spring 2026, examined 7,122 radar images from more than 60 offshore farms during 2020–2022 and reported an average 12.4% reduction in sea-surface wind speed, with wake signatures extending beyond 60 miles. Because the in situ lidar, on-site power logs and satellite radar independently show similar signals, the effect is harder to dismiss as an isolated instrument error.

Why weather, height and arithmetic change the headline numbers

The studies and scans carry caveats that explain the gap between single-scan peaks and seasonal losses. The satellite average of 12.4% was measured at 33 feet above the sea, and the authors note conditions at hub height can differ. A single lidar scan is a moment in time and does not equal an annual mean. Crucially, stable atmospheric conditions — when the sea surface and the lower atmosphere do not mix much — let wakes remain coherent and travel far; turbulent, well-mixed days break the corridor up and dilute the effect.

Small changes in wind speed have outsized effects because a turbine’s power output grows roughly with wind speed raised to the third power. The study’s authors offer a rule of thumb: reducing wind speed by 0.1 (ten percent) cuts a rotor’s power by about one quarter. For that reason, even brief, modest speed shortfalls can produce materially lower revenue in long-term production models.

Ownership, planning and the gap in compensation

The practical problem is legal and commercial, not just aerodynamic. Each farm’s permits and financial models assume its wind resource is independent; seabed lease lines do not stop moving air. No government or industry body has established a mechanism to compensate downwind farms for lost production when an upwind operator’s wake reduces inflow. The satellite authors explicitly call out the absence of settlement or legislation and expect published measurements to accelerate debate.

That gap matters because developers and financiers priced projects on resource assessments that did not account for long-distance wakes between separate concessions. The lidar campaign and the satellite review together shift the conversation from anecdote to measurable interference, creating a factual basis for operators to ask for design changes, curtailment agreements, or policy remedies. Absent contractual change, downwind farms facing repeated deficits may have to treat the exposure as an operational constraint rather than a solvable neighbor dispute.

Two-sided outlook

The bottom line

The lidar campaign and the later satellite review together move offshore wind wakes from hypothesis into measured reality: operators on a 400 MW North Sea platform saw slower air arriving from clusters 16 and 34 miles away and logged matching production losses. The datasets do not by themselves set who pays, and caveats — measurement height, episodic weather and model gaps — limit direct annual loss estimates. Still, a public measurement record and a 2026 satellite study of 7,122 images supply a factual basis for commercial negotiations and policy change. Expect stakeholders to use these measurements to press for new mitigation, monitoring or settlement mechanisms.

What to watch

• Watch for industry or government consultations on cross-farm wake compensation; no date has been set.
• Watch for publication or follow-up from the 2026 satellite study authors clarifying differences between measurements at 33 feet and hub height; no date has been set.
• Watch for operators to publish design or curtailment agreements referencing lidar evidence; no date has been set.