The High Court has ordered night-time shutdowns and other operating restrictions on a wind turbine after concluding that measures trialled by Meenacloghspar (Wind) Limited had failed to stop noise nuisance affecting neighbouring residents.
In an earlier phase of the case, Ms Justice Emily Egan found that turbine T2 caused nuisance to plaintiffs Margaret Webster and Keith Rollo, and Ross Shorten and Joan Carty, during night hours and quieter waking periods. The noise included high levels of amplitude modulation, described as periodic rises and falls in turbine noise, along with a particularly intrusive "thump" characteristic.
Rather than immediately imposing a shutdown, the court gave the parties an opportunity to explore mitigation. Between July and September 2024, the operator trialled one lower-power setting, reducing T2 from its normal 2,300kW mode to 1,600kW.
The court found that this did not materially improve matters. The mode reduced overall noise by no more than about 2.1 decibels at relevant higher windspeeds, a change described as barely perceptible or imperceptible, while leaving the principal intrusive characteristics unchanged.
The company also sought to introduce new analysis of older noise data and persuade the court to revisit its earlier finding of liability. Egan J. refused. She held that the evidence could have been produced with reasonable diligence during the first phase of the trial and, in any event, would not have altered the nuisance finding.
Turning to remedy, the court held that damages alone were inadequate and that an injunction was required. Renewable-energy production was treated as a relevant public interest, so the order was tailored rather than imposing a complete shutdown.
At night, T2 must be shut down at windspeeds from 5m/s to 11m/s, except within a wind-direction sector where nuisance was not established. At 12m/s and above it may operate in a reduced 1,200kW mode. During quiet waking hours, different restrictions apply depending on windspeed, including shutdown at 5m/s to 7m/s and reduced-power operation at 8m/s and 9m/s.