Both parties in the coalition government got elected on promises to decarbonise the UK’s energy sector. But as the next election nears, is the government considering extending the life of the UK’s most polluting energy source, coal?

The UK’s coal power plants are getting old, with many that were built in the 1970s and 80s due to be shut in the next few years. But in theory, the plants could be upgraded and kept open for another decade or so.

Yesterday, consultants Parsons Brinckerhoff released a government-commissioned report looking into the cost of keeping the UK’s coal power plants online. The report could be seen as the next step in a government plan to keep existing coal plants running, although the Department for Energy and Climate Change denies this.

So does the report offer any insights into the future of coal in the UK?

Paying to keep coal burning

There are two things that could influence the government’s decision on whether to keep coal plants open: economics and politics.

Yesterday’s report contains detailed estimates of what would need to be done to keep the UK’s fossil fuel power plants open. It says companies would have to spend millions to upgrade existing equipment and add new technology to reduce the plant’s emissions.

In January 2016, the European Commission’s Industrial Emissions Directive (IED) will require existing fossil fuel power plants to reduce their nitrous oxide emissions to 200 milligrams per normal cubic meter. That’s about half the emissions they were allowed under the Large Combustion Plant Directive, which the IED replaces.

To get to that level, the plants will have to add technology that converts the nitrous oxide into nitrogen and water. If the plants choose not to comply with the IED, they will have to curb their operational hours and close by 2023.

Parson Brinkerhoff’s figures seem to suggest it could be around £147 million to keep an average-sized 1,000 megawatt coal power plant going for an extra 10 years.

The main bulk of that cost comes from upgrading the plant’s technology to meet new pollution standards – that technology could cost £130 million to install on an average-sized, 1,000 megawatt, coal plant, with another £1.34 million needed to keep the technology running. Companies would also need to spend around £16 million upgrading the plant’s pipework to ensure it remains safe.

For comparison, building a new coal power plant of a similar size cost around £1 billion. If the plant has carbon capture and storage technology added – made necessary by the UK’s legally binding climate targets – it could cost closer to £3 billion.

Parson Brinckerhoff’s figures don’t include the cost of meeting any greenhouse gas emissions regulations. These are likely to become “more and more stringent” over time, it says, as policymakers work out ways to decarbonise the energy sector as a means to tackle climate change.

Once those extra costs are factored in, companies may decide it isn’t economical to keep the plants running without additional government support.

The politics of coal

If the UK government were to explore ways to encourage the continued use of fossil fuels, it would be a conspicuous departure from the coalition’s initial environmental promises.

In May 2010, David Cameron promised that if elected, his party would lead the “greenest government ever“. But as early as November that year, the Conservatives abandoned a pre-election promise to make existing coal power stations as clean as new gas plants. When it came time to vote on the plan, the Liberal Democrats eventually voted with their government colleagues – despite the party also initially supporting the plan.

Keeping coal power plants open would certainly damage the UK’s prospects of hitting its climate targets. The UK’s greenhouse gas emissions regularly rise or fall depending on how much coal is used for power generation. Coal plants currently generate about 36 per cent of the UK’s electricity.

The government’s official scientific advisor, the Committee on Climate Change, says politicians must find ways to phase out coal power to keep to the UK’s legally binding emissions reduction target. One way to do this would be to temporarily extend the life of less-polluting gas plants, which Parsons Brinckerhoff also looks into.

Alternatively, the government could seek to weaken its carbon targets if it decides Parson Brinkerhoff’s figures make extending the lives of coal power plants feasible. It wouldn’t be the first time a government report has led to questions over its commitment to tackling climate change.

Campaign group Greenpeace’s chief scientist Doug Parr expressed concern about the message commissioning the report sends. “If you were plotting to extend the life of coal power plants, this is exactly the report you would commission”, he told Carbon Brief.

DECC denies this is the case, however. A spokesperson told Carbon Brief the figures are intended to “provide up-to-date information to policy makers on all sides of the climate change debate. The UK government’s commitment to a low carbon future remains unchanged.”

Political parties have already started their long campaigns leading up to the general election next May. That the possibility of keeping the UK’s coal power plants open appears to be a possibility perhaps shows how little has changed since last time round.