"Transmission constraint costs in Great Britain hit £1.9 billion in 2024/25, accounting for 71% of total balancing costs. That share has risen from 44% in 2022/23 and is on course to reach £4-8 billion annually by 2030 without major intervention. The bottleneck is Scotland.
In 2025, turning down Scottish wind cost around £350 million. Replacement generation (mostly in the form of gas) cost over £1 billion. Curtailment is now the primary driver of Great Britain’s national balancing costs."
Also an outdated grid network.
"Transmission constraint costs in Great Britain hit £1.9 billion in 2024/25, accounting for 71% of total balancing costs. That share has risen from 44% in 2022/23 and is on course to reach £4-8 billion annually by 2030 without major intervention. The bottleneck is Scotland.
In 2025, turning down Scottish wind cost around £350 million. Replacement generation (mostly in the form of gas) cost over £1 billion. Curtailment is now the primary driver of Great Britain’s national balancing costs."
https://modoenergy.com/research/en/gb-great-britain-battery-energy-storage-curtailment-wind-constraint-scotland-costs