Data points to unprecedented decline of two-thirds this year due to doubling of carbon tax and low gas price

The amount of electricity generated from UK coal power stations is on track to fall by two-thirds this year, a decline which analysts said was so steep and fast it was unprecedented globally.

Climate change thinktank Sandbag said the drop was due to a doubling in the price of a carbon tax and the lower price of gas. The group has written to the chancellor, Philip Hammond, urging him not to water down the carbon floor price in this month’s autumn statement, which the steel industry has been lobbying the government to do.

Using data up to the end of October from the Office for National Statistics and the national grid, the thinktank estimated coal generation would fall 66% by the year’s end. Coal generation fell 23% in both 2015 and 2014 on the year before, and 10% in 2013.

Energy industry sources said the forecast for 2016 appeared to be broadly in line with expectations.

This year has seen a series of record lows for coal after three major plants closed, including the last remaining coal plant in Scotland. For several days in May the country’s coal plants produced no power for the first time in more than a century, and output was so low that from April to September, solar panels generated more power.

“It’s on top of four years’ worth of falls,” said Dave Jones, an analyst at Sandbag. “That fall is completely unprecedented. Everyone’s talking about what they can do to reduce greenhouse gas emissions, people talk a few percentage points here or there, but 66% is completely unprecedented in any country ever.”

Jones said the price of a tonne of carbon doubling from £9 to £18 in 2015 under the carbon floor price scheme was the driving force making coal plants uneconomic. Gas, which has been cheaper this year, has largely filled the gap in recent months.

The government last year pledged to phase out coal power entirely by 2025 to help meet its climate change commitments, but is yet to issue a consultation on the move. Sandbag said the decline in coal had seen emissions from the fuel go from 22% of the UK’s total carbon footprint in 2012, to just 5% now.

Official statistics show emissions dropped 4% in 2015 due to a rapid decline in coal, and the fall will almost certainly be much greater this year.

“The carbon price support has driven a remarkable decarbonisation of UK electricity,” said Jones. “The UK is now on track for a coal phase-out before 2025, but the chancellor must maintain the carbon price support, or emissions will begin growing again.”

UK Steel confirmed it was lobbying the government to reduce the carbon floor price to bring down energy prices.