Zero-carbon energy became Britain’s largest electricity source in 2019, delivering nearly half the country’s electrical power and for the first time outstripping generation by fossil fuels.

Following a dramatic decline in coal-fired power and a rise in renewable and low-carbon energy, 2019 was the cleanest year for electrical energy on record for Britain, according to National Grid, which owns and operates the electricity transmission network in England and Wales, and also runs the Scottish networks.

National Grid’s latest data shows that wind farms, solar and nuclear energy, alongside energy imported by subsea cables, delivered 48.5% of Britain’s electricity in 2019. This compares to 43% generated by fossil fuels – coal, gas, and other carbon sources such as oil and diesel. The remaining 8.5% was generated by biomass, such as wood pellets.

This milestone comes as the UK enters the mid-point between 1990 and 2050, the year in which it has committed to achieve at least a 100% net reduction in greenhouse gas emissions based on 1990 levels, and to become a net zero carbon economy.

A decade ago, fossil fuels generated more than three-quarters of all electricity, while zero-carbon sources accounted for less than a quarter (22.8%), with wind at 1.3%. Then, coal plants provided almost a third of the UK’s electricity. This has dwindled to 1.9%, and Britain set a new record for going without coal-powered energy altogether in summer 2019: it went for 18 days from May to early June without using coal to generate electricity, the longest such run since 1882.

By the end of this winter, the UK will be left with only four coal fired power plants. EDF Energy’s Cottam coal plant in Nottinghamshire closed this year and two other coal plants, RWE’s Aberthaw B and SSE’s Fiddler’s Ferry, are due to close in March 2020.

The National Grid figures show a dramatic shift in the last two decades. Wind farms, solar panels and hydro power now generate just over a quarter of Britain’s electricity, compared with 2.3% in 1990. Nuclear power accounts for 17%, compared with nearly 20% in 1990. However, the use of gas – a fossil fuel – also shot up to generate more than 38% of the country’s electrical power last year, compared with just 0.1% in 1990.

National Grid’s chief executive John Pettigrew said: “As we enter a new decade, this truly is a historic moment and an opportunity to reflect on how much has been achieved.

“At National Grid, we know we have a critical role in the acceleration towards a cleaner future and are committed to playing our part in delivering a safe and secure energy system that works for all.”

Other recent government figures showed that the UK’s growing fleet of offshore wind projects generated more electricity than onshore windfarms for the first time in the third quarter. Since then, wind power reached fresh highs during blustery weather in early December to generate almost 45% of the UK’s electricity on one day.

In December, National Grid unveiled plans to invest almost £10bn in the UK’s gas and electricity networks over the next five years. Of this, almost £1bn has been earmarked for the transition to a net zero carbon electricity system by 2025, including investments in new equipment and technology.

A further £85m will support changes to the ways people heat their homes, switching away from gas boilers to technologies such as electric heat pumps and hydrogen boilers. National Grid estimates that more than 23 million homes will need to install new low-carbon heating solutions by 2050.

• This article was amended on 3 January 2020 to make clear, for avoidance of doubt, that various references to energy and power meant electricity only.