UK power sector emissions hit record low in April

The carbon intensity of the UK's power generation declined in April to its lowest monthly average on record, as Covid-19 restrictions, coupled with milder weather, suppressed power demand, pushing coal-fired generation almost entirely out of the generation mix.

The UK power sector produced an average of around 148g CO2/kWh in April, down from an average of 170g CO2/kWh in March and 192g CO2/kWh in April last year, data from Imperial College London and UK utility Drax show. This was the lowest average for any month since at least 2009, when records began.

Lockdown measures introduced on 23 March to slow the spread of the coronavirus significantly curtailed electricity demand last month, as much industrial activity came to a standstill and the majority of the UK's workforce was operating from home.

In addition, mild weather prevented the heating demand period from extending into the month, limiting any residual power demand for electric heating that might otherwise have been present over the period. Temperatures held, on average, 1.5°C above the seasonal norm in London last month.

Overall UK power demand averaged just 26.77GW last month, down from 33.09GW in March and 32.05GW in April of last year, squeezing fossil-fuel generation units with higher marginal costs out of the generation mix.

Gas-fired production dropped to an average of just 8.5GW — 30.8pc of the UK's total generation mix — in April, down from 11.3GW in March and 13.3GW in April 2019.

And coal generation was close to zero over the month at an average of 140MW, accounting for just 0.5pc of the generation mix. This was down from an average of 650MW in March and 390MW in April of last year. Clean dark spreads held comfortably in negative territory throughout the month.

The fall in power demand was significant enough to see cuts in fossil-fuel generation despite lower wind power output, which dropped to an average of 6GW in April — or 21.5pc of the energy mix — from 9.3GW, or 28pc, in March. This was roughly in line with the April 2019 average of 6.1GW.

Given that Covid-19 restrictions are likely to be maintained for at least the majority of May, power demand, and therefore the UK power sector's carbon intensity, is likely to continue to turn out much lower, both next month and overall this year. CO2 intensity has averaged just 165g CO2/kWh for the year to date, compared with 203g CO2/kWh over the first four months of 2019.

But with the UK announcing that it has passed the peak of its coronavirus infections, some of the tightest limitations could begin to ease next month, potentially lifting power production levels slightly from those seen in April. And cooler weather over the coming month could spur some heating demand. Temperatures in London are forecast to average just 11.7°C over 1-15 May, some 1.3°C below the seasonal norm.

By Victoria Hatherick

UK average power generation MW