Kilroot power station owner AES Kilroot plunged into the red during 2015 due to lower electricity prices, according to its latest results.
Operating profits at the firm were wiped out, with a profit of £14.8m in 2014 replaced by a loss of £14.8m in 2015. Pre-tax profits were also extinguished, going from £38m to a £7.3m loss.
Turnover was also down 15% from £133.5m to £113.6m.
The company said the losses were due to lower prices on the spot electricity market and that results were as expected by the directors, given the prevailing market conditions.
And in a strategic report filed with the results at Companies House, director Roger Casement said that milder weather and unfavourable gas/coal spread, as well as more outages, had all contributed to falling turnover.
Looking ahead, the company said it expected that operational and financial activity for its generating units would improve over the next year. It had recently spent £7m on upgrading technology.
The business operates in the single electricity market, which sells electricity into markets in Northern Ireland and the Republic.
It's part of Fortune 200 global power company AES Corporation, and a sister company of AES Ballylumford, which owns the Ballylumford power station.
At AES Ballylumford, sales were down 20% during 2015 from £133.5m to £113.6m, while pre-tax profits fell by more than 50% to £6m.