A fault has been detected on the Moyle Interconnector, a critical undersea cable linking Northern Ireland with Great Britain.
Mutual Energy, which operates the facility, confirmed that the cause is currently under investigation.
It is not yet possible to determine when repairs will be completed or when service will resume.
System Operator NI (SONI) has published its annual winter outlook regarding the situation.
The operator's base-case scenario assumes the interconnector will return to full service before the peak demand period arrives.
According to SONI, gas-fired power stations in Northern Ireland are expected to operate without restriction due to environmental regulations.
This means domestic and industrial electricity needs can be met through local generation despite the loss of cross-border import capacity.
The incident does not appear to have triggered any immediate emergency response measures.
No specific timeline for restoration has been provided by Mutual Energy at this stage.
System Operator NI (SONI) maintains that current power output levels are adequate to supply the region throughout the winter months.
Investigation into the technical failure continues as operators work to restore normal connectivity between the two islands.