The ESB subsidiary that runs the Dublin Bay power plant in Ringsend saw profits rise by almost a quarter last year, newly filed accounts show.

Synergen Power Limited recorded pretax profits of €50.3 million, up nearly 24 per cent versus the €40.7 million reported a year earlier.

Turnover rose from €198.5 million to €205 million while the company reported an operating profit of €51 million as against €42 million in the prior year.

“The 2015 profits were higher than 2014 due to a combination of factors including lower fuel costs and higher plant availability which had a positive impact on cost of sales and turnover compared to the previous year,” the ESB said.

Synergen operates a 400 megawatt combined cycle gas-powered generation plant that uses natural gas to generate electricity for the wholesale market. The company estimates it supplies about 8 per cent of the total market requirement.

The power station, which was commissioned in 2002, opened amid controversy, having been built by ESB shortly before the electricity market was deregulated.

The plant was originally a joint venture between ESB and the Norwegian energy giant Statoil. However, the latter sold its 30 per cent stake in the plant in early 2006 to Royal Bank of Scotland (RBS) in a deal valued at €75 million. ESB subsequently acquired RBS's interest.

The plant is now owned by ESB International and operated and managed by another ESB subsidiary, Utility Operation and Maintenance Services Limited.

Directors said they were pleased with the progress made by the company during the year and approved a €37 million dividend to its parent. This compares with an €80 million dividend in 2014.

As the management of Synergen are seconded from ESB Group, the company has no direct employees.