NSL interconnector trip causes GB grid frequency dip, batteries respond
EIR-0757Provisional entry. Published from first reports and rechecked automatically as more sources appear. No further update is scheduled; the entry stays provisional until new information is published.
On 8 October 2024 at 8:47am local time, the NSL interconnector, which links the UK and Norway, suddenly stopped exporting power, with imports falling from 1.4GW to zero. Grid frequency on the British network fell as low as 49.59Hz within two seconds, breaching the National Energy System Operator's normal operational limits of 49.8 to 50.2Hz. The system recovered within two minutes as fast-acting frequency response services, particularly battery energy storage systems from several operators, injected power into the grid. Around 1.5GW of batteries across the network responded, including assets optimised by Arenko Group and Kraken, with Kraken-optimised batteries alone delivering over 450MW of response, equivalent to roughly a third of the power lost. No damage, injuries or wider blackout resulted from the event.
Sudden and unexplained loss of 1.4GW of interconnector import capacity from the NSL Link between the UK and Norway.
- Interconnector trips can cause rapid, significant frequency deviations even on well-managed grids.
- Diversified, fast-acting battery storage fleets contracted for frequency response can arrest large frequency excursions within seconds to minutes.
- Aggregation of battery assets across multiple operators and optimisers increases system resilience to single points of failure such as interconnector outages.
Published 2026-09-15. Written from public reporting. Descriptive, not investigative. See the data accuracy disclaimer.