Exclusive: Reliance on fossil fuels fell in August to less than one-fifth of all electricity generated across country

Great Britain’s electricity system has recorded its greenest ever summer after growing numbers of wind and solar farms cut the need for gas power plants to fresh lows.

Analysis of energy generation data, commissioned by the Guardian, revealed that Britain’s reliance on gas generation fell in August to less than one-fifth of all electricity, or 4 terawatt hours (TWh), its lowest ever level for a one-month period.

This allowed the carbon intensity of the power grid to plummet to the lowest level recorded for a single month, at 144g of CO2 per kilowatt-hour in August, 40% lower than in the same month last year, according to the analysis.

The data, analysed by the energy thinktank Ember, showed that the record lows were sustained even when averaged over the summer months from June to August, meaning the grid experienced its greenest summer ever.

The Labour government aims to run the UK’s power grid on virtually zero carbon electricity by 2030 thanks to a surge in new wind and solar farms. Its flagship auction this week for renewable energy subsidies awarded contracts for 131 new projects, or enough new clean electricity projects to power 11m UK homes. However, it secured just half the offshore wind capacity needed every year for the rest of the decade if the government is to hit its net zero target.

Read more: TheGuardian