The London mayor has been working towards the target for some years, saying it forms just one part of having a ‘net zero London’ by the start of the next decade.
Replying to a written question from Emma Best, a Conservative on the London Assembly, Mr Khan said that Transport for London (TfL) in February this year relaunched its first Power Purchase Agreement tender, which he said will provide about 10 per cent of TfL’s required energy from renewable sources.
He added that he expects the contract for that first tender to be signed in early 2024.
“This marks the first in a series of tranches where TfL will go out to procure new build renewables and is its first major step towards ensuring it meets our goal of being net zero by 2030,” he said.
According to National Grid, 2020 marked the first year in the UK’s history that electricity came predominantly from renewable energy, with 43 per cent of the country’s power coming from a mix of wind, solar, bioenergy and hydroelectric sources.
That means that the Tube is currently far below the UK average in terms of the proportion of its electricity generated by renewables.
But Helena Bennett, head of climate policy at the think tank Green Alliance, commended the mayor’s ambition.
“The growth from 10 per cent in 2024 to 100 per cent in 2030 I think is quite ambitious,” she said.
“Obviously at the moment it feels quite low, [to have 10 per cent in] 2024. If you look at the wider UK grid, obviously much more of that is electrified than the London Underground is using.
“But because they’re trying to sign these power purchase agreements, they’re often quite competitive and not that easy to get going, so it’s understandable that it’s maybe taking a bit longer.
“I think the key thing is the ambition of how quickly that’s going to scale up over the next half a decade - that’s the thing to focus on.”
She added: “Transport is still the highest-emitting sector in the UK, so we need to do as much as we can to decarbonise it as quickly as possible.
“Rail and the Underground count for quite a small proportion of those emissions, but every little part of the puzzle is helping to get the UK towards net zero.”
According to the Government, transport accounted for around 34 per cent of the country’s carbon emissions in 2022, of which the “large majority” was from road transport.