EU court rules against Britain over power plant emissions

(Adds RWE, Welsh government comments, background)

BRUSSELS, Sept 21 (Reuters) - Britain failed to respect European Union limits on nitrogen oxide emissions from a coal-fired power plant in Wales, the European Court of Justice said on Wednesday.

The European Commission launched an inquiry in May 2012 into the environmental credentials of the Aberthaw plant and took Britain to court in March 2015. Britain can now expect a fine and will have to pay the Commission's legal costs.

EU member states were required to reduce emissions from large combustion plants by the start of 2008, with the Aberthaw plant operating of an nitrogen oxide emission limit of 1,200 mg/NM3 (milligrammes per normal cubic metre) against an EU limit of 500 mg/NM3.

The 45-year old power plant is designed to generate power using Welsh coal and its operator, German utility RWE (Amsterdam: RW6.AS - news) said it has invested hundreds of millions of pounds to improve the plant's environmental credentials.

Britain had argued that the Aberthaw plant should, under EU rules, have been allowed to emit a greater amount of nitrogen oxide because of the type of coal the plant used.

RWE (LSE: 0FUZ.L - news) said it was disappointed by the ruling and the result would be less locally-mined coal being burnt at the station.

"It will mean our ability to use large amounts of Welsh coal is reduced somewhat earlier than might otherwise have been necessary," said Richard Little, Aberthaw's power station manager, in a statement.

RWE said its investment plans for the station have not been affected and it believes Aberthaw can continue operating into the 2020s.

The Welsh government, which is responsible for environmental aspects of power plants in Wales, said it was committed to improving air quality across Wales. (Reporting By Philip Blenkinsop; Additional reporting by Karolin Schaps in London; Editing by Elaine Hardcastle)