Analysis: Great Britain hits coal-free electricity record amid coronavirus lockdown

Update 11 May 2020: The record coal-free stretch has now passed one month and counting.

Great Britain has run for a new record of 18 days, six hours and 15 minutes without burning coal to generate electricity – and counting – as the coronavirus lockdown cuts demand by nearly 20%.

This combination means CO2 emissions from the country’s electricity system have been cut by a third during the coal-free stretch relative to the same period last year, Carbon Brief analysis shows.

During the record-breaking period, demand has been 18% lower than last year, as businesses around the country are closed due to the coronavirus response.

Renewables have been the largest source of electricity, supplying 37%, with another 32% from gas and 22% from nuclear. The remaining 9% has been imported from France, Belgium and the Netherlands.

The figures are in stark contrast to 2012 – the earliest available detailed data – when coal supplied some 43% of the total for Great Britain, another 26% was from gas and just 7% was from renewables.

Coal-free record

Back in 2016, just before midnight on 9 May, Great Britain’s electricity system ran without coal-fired power stations for the first time since a public grid had been established in 1882. After some four hours of coal-free operation, one of the country’s remaining coal plants switched back on.

Just under a year later, the grid ran coal-free for a full 24-hour period that ended on 21 April 2017. The first coal-free week in early May last year was quickly followed by a first fortnight, which went on to set the current record coal-free run of 18 days, six hours and ten minutes.

Early this morning, Tuesday 28 April, a new record was set at 18 days, six hours and 15 minutes – and counting. Great Britain’s coal plants switched off at 23:45 on Thursday 9 April, just before the Easter long weekend, and have not resumed operation as of 06:00 today.

A brief history of this new record coal-free stretch is shown in the animation, below.

The use of coal to generate electricity has been plummeting and is down from a 40% share of UK supplies in 2012 to 25% in 2015 and 2% last year. There are several reasons for this decline.

Chief among these is steadily falling electricity demand and a huge increase in renewable generation. Another important factor is the UK’s top-up carbon tax, known as the “carbon price support”, which was introduced in 2013 and reached £18 per tonne of CO2 in April 2015.

This rapid decline can be seen in the chart, below, showing daily average electricity output from coal-fired power stations in Great Britain. As a result of this trend, almost all of the UK’s coal plants have closed in recent years, well ahead of a deadline to phase out the fuel by 2024.

Daily average electricity output at coal-fired power stations in Great Britain, megawatts, from 2012-2020 to date. Source: Carbon Brief analysis of data from BM Reports. Chart by Carbon Brief using Highcharts.

Most recently, Aberthaw B in south Wales and Fiddler’s Ferry in Cheshire closed at the end of March 2020, leaving just three plants operational in Great Britain – Drax, Ratcliffe, West Burton – along with one more, Kilroot, in Northern Ireland.

Whereas more than two-thirds of electricity supplies in 2012 had come from fossil fuels, including more than two-fifths from coal and another quarter from gas, Great Britain now gets comfortably more than half of its electricity from low-carbon supplies, as the table below shows.

	Record stretch	Same period in 2019	2020 to date	In 2012
Coal	0%	1%	3%	43%
Gas	31%	41%	32%	26%
Nuclear	22%	21%	18%	21%
Imports	9%	7%	8%	3%
Biomass	8%	5%	7%	1%
Wind	17%	17%	25%	4%
Solar	9%	7%	4%	0%
Hydro	2%	1%	3%	2%
Other	1%	0%	0%	0%
Fossil	32%	42%	36%	69%
Renewable	37%	30%	38%	7%
Low-carbon	59%	51%	55%	27%
Carbon intensity (gCO2/kWh)	160	199	186	508
Average daily demand	24,858	30,069	31,318	36,116

In 2020 to date, barely more than a third of electricity in Great Britain came from fossil fuels, of which the vast majority was from gas. (Note that gas-fired electricity generation has also fallen relative to levels in 2010 – fossil fuels have been replaced by lower demand and renewables.)

Lockdown low

One contributor to the current situation is the ongoing coronavirus crisis, with countries around the world locking down their economies in a bid to control the spread of cases and stem the loss of life.

On 23 March, strict controls were introduced on daily life in the UK, forcing many businesses to close their doors. As in other countries implementing such measures, electricity demand has fallen.

Hourly demand for electricity in 2020 (red lines in the chart, below) has been generally lower than in either of the previous two years (2018, grey, and 2019, blue), in part due to a warm winter. Even so, the chart shows a marked reduction in demand starting in late March and persisting ever since.

Hourly electricity demand in Great Britain, megawatts, in 2018-2020 to date. Source: Carbon Brief analysis of data from BM Reports. Chart by Carbon Brief using Highcharts.

In the month of April 2020 to date, Carbon Brief analysis shows that electricity demand has been 18% lower than in the same period last year – and 21% below the average for the past five years.

With demand being so much lower than usual, gas generation has also been lower than last year – down some 37% on 2019 levels – despite the grid being coal-free throughout the period.

This means that CO2 emissions from electricity generation in Great Britain this April to date are down 34% compared to the same period in 2019 – and 51% below the five-year average.

Renewables reign

During the record coal-free run itself, as of 06:00 on 28 April, the largest source of electricity supplies in Great Britain was renewables, meeting 37% of demand. Gas accounted for 31% and nuclear another 22%, with imports from France, Belgium and the Netherlands at 9%.

The hourly contribution from each fuel is shown in the chart, below, which also illustrates the daily cycle of reduced demand at night and peaks in solar output (yellow) during daylight hours.

Hourly electricity generation in Great Britain, by fuel, during the record-breaking coal-free run from 9-28 April. Source: Carbon Brief analysis of data from BM Reports. Chart by Carbon Brief using Highcharts.

Note that when Great Britain is exporting electricity to other countries rather than importing it as usual, the nuclear part of the chart (purple) appears to dip below zero. These dips tend to be in windy periods when Great Britain’s windfarms are generating large amounts of electricity.