Cabling constraints have resulted in around 77% of the potential output from Scotland’s largest offshore wind farm being curtailed, according to recent accounts.

The Seagreen offshore wind farm, operated by SSE, generated 1,040 gigawatt-hours (GWh) of electricity in the year to March 2025, despite having the capacity to produce 4,590 GWh. 

The remaining output was constrained due to limited grid capacity, with payments made by the National Energy System Operator (Neso) to switch off turbines.

Seagreen, which comprises 114 turbines around 17 miles off the Angus coast, is thought to be among the most heavily curtailed wind farms in the UK. 

Estimates suggest more than £30million was paid to the project in 2025 to compensate for lost generation. Nationally, the cost of constraint payments reached almost £1.5 billion in 2025, funded through levies on consumer energy bills.

Commenting, SSE said: 
“A wind farm switched off represents potential waiting to be unlocked. The UK has built renewables where the resources are strongest, and now we need to upgrade the grid to eliminate bottlenecks so we can harness more of that energy, more of the time. 

"SSE is investing £27billion between 2025 and 2030 to remove bottlenecks and unlock the full potential of our clean power system — helping deliver energy security and lower bills for households and businesses.”

KeyFacts Energy: SSE UK country profile