Skip to content
You can now search across every topic, entity and event.What's new
SONI
OrganisationGB

SONI

The System Operator for Northern Ireland, which co-issued a fault-ride-through demand-curtailment procedure with EirGrid for data-centre customers.

Last refreshed: 15 July 2026 · Appears in 1 active topic

Timeline for SONI

#1029 Jun

Co-issued the fault-ride-through curtailment procedure with EirGrid

Data Centres: Boom and Backlash: Ireland codes a 900 MW load-loss limit
View full timeline →
Follow Data Centres: Boom and Backlash →
Common Questions
What is SONI?
SONI is the System Operator for Northern Ireland, which runs the transmission grid as part of the all-island Single Electricity Market shared with EirGrid.Source: event
Why did SONI and EirGrid set a 900 MW demand-loss limit?
They issued the limit to manage the risk of hyperscale data centres disconnecting simultaneously during a grid fault, which could destabilise the all-island electricity market.Source: event
When did Ireland's fault-ride-through procedure take effect?
EirGrid and SONI issued the procedure on 30 June 2026, and it took effect from July 2026.Source: event

Background

SONI, Northern Ireland's electricity System Operator, co-issued a fault-ride-through demand-curtailment procedure with the Republic of Ireland's EirGrid on 30 June 2026, live from July, setting a 900 MW ceiling on instantaneous demand loss from data-centre customers and warning of grid imbalance above 1,150 MW without mitigation.

SONI operates the transmission grid in Northern Ireland as part of the all-island Single Electricity Market it shares with EirGrid, coordinating supply and demand across the border rather than as two separate systems. The joint procedure reflects that shared responsibility: a sudden loss of demand on one side of the island can destabilise the whole market.

The ceiling is a direct response to the scale hyperscale data centres now bring to the island's grid. If a fault causes multiple large loads to disconnect simultaneously rather than ride through it, the resulting imbalance could exceed what the grid can absorb without emergency measures.