THE north faces a "real challenge" keeping the lights on from 2021, the System Operator for Northern Ireland (Soni) has warned.
The company runs and develops the north's electricity grid and wants to build a new interconnector between Northern Ireland and the Republic.
It its latest annual forecast of supply and demand - the Generation Capacity Statement - the company said Northern Ireland would not have "adequate supply" within five years.
That's because two large generators at Kilroot Power Station are set to wind down.
However, Soni general manager Robin McCormick said all concerns "would be addressed by the building of the second north-south interconnector”.
“As the system operator, unless action is taken we won’t be confident that we can keep the lights on in 2021," he said.
“This could be a particular issue during the winter months, because the supply may not be sufficient to meet the daily peaks in demand.”
Mr McCormick said the building the new interconnector "would allow us to remove restrictions that we have had to place on the existing interconnector and would see Northern Ireland benefit from a secure supply of electricity".
"That is why it is so important that we have the north-south interconnector operational by 2020," he said.
An oral hearing into the north-south interconnector is due to take place in the Republic this month.
Meanwhile, a stalled public inquiry in the north is expected to recommence by May at the earliest.
The report also highlighted that demand for electricity in the north is stabilising and could experience some modest growth.
It also forecast increasing contributions from solar and biomass plant.
