UK to be left with five coal power stations after latest closure.

News comes as National Grid announces greenest winter for energy use after mild weather.

The UK’s race to increase renewable energy sources has intensified with the announcement of plans to close another coal-fired power station.

The news on Thursday came as last winter was revealed to be the greenest yet for the country’s energy system, after strong winds produced more renewable electricity and coal-fired power dwindled.

SSE said Fiddler’s Ferry near Warrington, Cheshire, the energy company’s last remaining coal-fired power station, would close in March 2020, reducing the UK’s coal-fired energy fleet to five plants.

National Grid, the operator of the UK’s electricity network, said mild temperatures combined with strong winds ensured the carbon intensity of Britain’s electricity – the amount of carbon produced for every kilowatt of electricity – fell to an average of 242.8 grams of carbon between October and March, from 280.2 grams a year earlier.

National Grid said the UK relied less on coal power plants over winter, partly because it was the fifth-warmest recorded in the past 59 years. The milder temperatures dampened energy demand, making it easier to avoid using coal in favour of running gas power plants, which produce half the carbon emissions.

Meanwhile, stronger wind speeds helped drive down carbon emissions by spurring higher levels of low-carbon renewable electricity from windfarms.

Elsewhere in the world, severe winters and hotter than normal summers have had the opposite effect, driving up energy demand to run heating and cooling systems, increasing global emissions.

National Grid said the UK’s carbon intensity was almost half the level of five years ago and was likely to fall further as coal plants shut down. The report emerged weeks after the country’s energy system ran coal-free for more than a fortnight for the first time since the Industrial Revolution.

Fintan Slye, the head of National Grid’s system operator arm, said: “More renewable power generation and less coal is a trend that is here to stay, and this carbon intensity milestone shows the pace of change in the UK energy industry.

“We believe that by 2025, we will be able to fully operate Great Britain’s electricity system with zero carbon.”

Coal-fired power made up 5% of the UK’s electricity over the winter and will be phased out altogether by 2025 under a government ban. Wind power and nuclear plants each made up 18% of the power generation mix, while gas-fired power plants produced 42%.

Stephen Wheeler, the managing director of thermal energy at SSE, said Fiddler’s Ferry could not compete with the economics of gas and renewable energy.

He said SSE made the “difficult decision” because the plant is losing £40m a year, as government policy focuses on supporting less carbon-intensive forms of energy.

“Financially, the station is making significant losses and our projections show that this will continue to be the case as the UK looks to phase out coal-fired generation by 2025 at the latest,” he said.

“At nearly 50 years old, the station is unable to compete with more efficient and modern gas and renewable generation.”

SSE’s announcement follows EDF Energy’s plan to close the Cottam coal plant in September, which it announced after a winter of record-low coal generation.

Once Cottam and Fiddlers Ferry shut, the UK’s remaining coal plants will be Aberthaw B in South Wales, West Burton A and Ratcliffe-on-Soar in Nottinghamshire, Kilroot in Northern Ireland and two generation units at the Drax site in Yorkshire, which are earmarked for conversion to burn gas.