By Mark Poynting

Labour’s manifesto stated that “clean energy by 2030 is Labour’s second mission”, pledging a “zero-carbon electricity system”.

Now, the government is defining the target as “at least 95% clean power by 2030”.

This follows a report by the National Energy System Operator, an independent body overseeing the energy transition.

It defined a clean power system as one where polluting gas, without technology to capture emissions, will “provide less than 5% of Great Britain’s generation in a typical weather year”.

Electricity generation from renewables drops during less sunny and less windy periods. Some gas is seen as necessary to fill these gaps.

Many emerging low-carbon technologies, such as battery storage, may be able to do this job in the future, but are still at early stages.

As a result, eliminating the final few percent of gas from the electricity mix by 2030 would be particularly challenging and would likely add to costs.

Shadow energy secretary Claire Coutinho has accused the government of watering down its pledge. The previous Conservative administration had also pledged 95% low-carbon electricity by 2030.