ESB results for 2014 show a fall in operating profit of €132m to €552m - a decrease of nearly 20%.
The company said the fall in profits is down to lower electricity wholesale prices on the back of lower gas prices; repair to significant storm damage during the first half of 2014 and a hit from maintenance and repair work at ESB's Moneypoint coal plant in Co Clare.
Its profits after tax slumped by 58% to €215m which the company said reflected lower operating profits, and was also linked to the low interest rate environment in the UK.
ESB spent more on capital investment last year - €960m, an increase of €135m on the previous year.
It said the total dividend paid to the Irish exchequer over the last ten years has reached almost €1.5 billion.
"In the face of some challenges in 2014, these results reflect a solid performance across the group. ESB continues to deliver value for its customers, its shareholders, and for the Irish economy, while maintaining its financial strength and credit rating," said ESB's chief executive Pat O'Doherty.
ESB also said the performance improvement programme it started in 2010 has delivered significant recurring savings across the business and has helped to offset the impact of lower margins in the generation business.