A UK power plant that made the ‘Dirty Thirty’ list of Europe’s most polluting power stations last month is generating new controversy.

Due to new European emissions laws, NOx emissions from the 1555 MW Aberthaw coal-fired plant (pictured) in south Wales are now more than five times over the legal limit.

The UK government is in talks with the European Commission (EC) in an attempt to keep the plant open, based on a previous emissions exemption it received because it uses difficult-to-burn coal with less than 10 per cent volatility from the surrounding region, and makes an important contribution to the local economy.

Under the exemption, the plant may emit up to 1200 mg/Nm3 NOx. But its operator, RWE npower, has recently begun burning a mix of local and more easily combustible imported coal, largely from Russia, with between 6 per cent and 15 per cent volatility. This has resulted in NOx emissions of around 1000 mg/Nm3, while the new European limit is 200 mg/Nm3.

According to the EC, this means the plant no longer qualifies for the emissions exemption and must be taken offline by 2016. The UK has asked that the plant still be classed as low-volatility and has submitted two plans to reduce its emissions to the previous exempted numbers, but due to “inconsistent or missing” data the EC has rejected the plans and begun infraction proceedings against the UK.

A spokesperson for the EC told The Guardian newspaper that “for the time being, the closure of the plant is not considered”.