The ESB Group lost €32m last year amid what the semi-state said were "challenging market conditions".
ESB said these challenges included increased competition and downward pressure on energy margins.
The company recorded a once-off €276m non-cash impairment charge during the year reflecting the value of its power generation assets.
It said its operating profit before this exceptional item amounted to €490m, down from €597m in 2016.
The ESB said it took the "prudent" decision to make the writedown due to the estimated impact on its revenues from the introduction of the new integrated Single Electricity Market in May 2018 and lower wholesale electricity margins.
ESB paid a dividend of €60m to the Exchequer for 2017, and said it has paid a total of €1.4 billion to the Exchequer over the last ten years.
The company also said that it invested €867m in energy infrastructure and other investments last year.
"ESB continued to focus on delivering long term value and investing in critical long term electricity infrastructure for the benefit of our customers, shareholders and the wider Irish economy," commented the ESB's chief executive Pat O'Doherty.
"ESB's solid underlying financial position ensures it is well positioned to lead the transition to reliable, affordable low carbon energy for Ireland," the CEO added.
