Q2 2020: Solar eclipses coal

by Dr Iain Staffell – Imperial College London 

May saw Britain’s solar panels produce more than ever, while every coal power station spent the whole month sitting idle. 

Solar panels supplied an average of 2.7 GW of power during May, surpassing 10% of the month’s electricity demand. Growing output from renewables, along with suppressed demand saw no coal power stations operate for 67 days straight.

Britain experienced unusually good weather, with sunshine levels during spring rivalling some of the best summers on record. Much of this was down to favourable conditions, a large patch of high pressure blocked incoming storms. Britain’s lockdown also had an influence, as greatly reduced traffic meant less air pollution at ground level, and greatly reduced air traffic meant fewer contrails, both of which absorb or scatter some of the incoming sunlight.

Weekly-average share of electricity generation from coal-fired power stations and solar panels

Britain also saw its first ever full month with zero electricity generated from coal. All of the country’s coal power stations had turned off as of midnight on 10th April, and stayed offline until 10 pm on 16th June, some 67 days later. One plant then ran for three hours (producing just around 25 MW) as part of routine maintenance. No electricity was produced from coal during 92% of the hours this quarter.

This collapse in coal output means Britain’s power system gets to celebrate its first ‘zero-coal anniversary’: at the start of July it had clocked up 8,760 hours without any coal – equivalent to a full year. It has taken four years to reach this point, since the first zero-coal hour back in May 2016, but it will most certainly take less time before we reach the second anniversary. 

Cumulative number of hours with zero coal-fired electricity generation in Britain