Profits at energy provider SSE Airtricity fell by almost 23% in the year to the end of March, which the company blamed on increased competition and increased energy costs.
The brand provides electricity and natural gas across the island of Ireland and it said it had 740,000 household and business customers by the end of March.
"Since we entered the market here in 2008, we've grown to become the second largest energy utility, and leading developer and generator of renewable energy, on the island," commented Stephen Wheeler, Managing Director of SSE Ireland.
"In that time, we've directly invested over €2.5 billion in the development of Ireland’s sustainable, low-carbon energy infrastructure, with four new onshore wind farms in the last 16 months, including Ireland’s largest in Galway," he added.
Mr Wheeler said the company is progressing plans to fully develop its Arklow Bank Wind Park project in the Irish Sea, which would represent an investment of over €1 billion and deliver a minimum of 520 megawatts of capacity.
He said that the country has an incredible wind resource off the coast. "We believe it's now time to harness that power and bridge the gap to our 2020 EU renewables targets and beyond," he added.
Meanwhile, a new study which was commissioned by SSE and conducted by PwC shows the scale of economic activity that SSE's operations support across Ireland.
The study reveals that SSE contributed €806m to Irish GDP, equivalent to 0.3% of GDP.
SSE said this latest figure takes the company's overall contribution to the Irish economy to more than €6 billion over the last seven years, while the company supported 4,520 jobs in Ireland last year, equivalent to 0.2% of total Irish employment.
SSE's full year earnings down 3.6%
The company's parent group, SSE, said its full-year earnings per share fell 3.6% due to customer attrition and weakness in its power networks business but profit so far this year remains ahead of its expectations, the British energy supplier said today.
Total customers for its domestic energy services fell nearly 6% to 6.8 million in the year ended March 31.
"While electricity tariffs increased to recognise rising non-energy costs, overall profits were also impacted by customer account losses and the introduction of price caps for certain customer groups, offset by ongoing efficiency savings," the company said.
Adjusted operating profit at its network business, which includes power transmission and distribution, fell 25.8% to £195.6m, mainly due to the phasing of capital expenditure on significant projects.
The country's second-biggest energy supplier said adjusted earnings per share fell to 121.1 pence from 125.7 pence a year ago, but was marginally ahead of company's prior guidance range of 116 to 120 pence.
Power suppliers in Britain have been under pressure from the emergence of small and aggressive rivals as well as by a cap on retail prices proposed by the government.
Britain's "big six" energy suppliers - Centrica's British Gas, Iberdrola's Scottish Power, E.ON, EDF Energy, SSE and Innogy-owned Npower - are all currently struggling.
SSE hiked its full-year dividend by 3.7% to 94.7 pence and said it could recommend a payout of 97.5 pence in the current year, an increase of 3% from a year ago.
Over the five years to March 2023, SSE said it expects to spend about £6 billion, with £1.7 billion in 2018-2019.
The merger of SSE's UK retail energy supply businesses with Npower is currently under investigation by British regulators.
The merger would create Britain's second-largest retail power provider and reduce the "big six" dominating the market to five companies.