Khan has made solar one of the key planks of his energy policy, supporting community solar projects and negotiating collective solar installations for homeowners in the capital.
But that approach is threatened by the government’s recent decision to let solar incentives expire next March without a replacement.
Shirley Rodrigues, a deputy mayor for London, said she had been very disappointed by the move. “We think the tariffs have been really helpful in increasing the take-up of solar and making it acceptable for people,” she said.
Under government plans, householders with solar photovoltaic panels – which convert solar radiation into direct current electricity – will no longer be paid for sending their unused electricity (from the PV system) back to the national grid under the export tariff arrangement. Rodrigues said that that was unexpected and unfair.
“At the very least, the export tariff should be kept for two years while we work out an approach that doesn’t result in installations dropping off and losing jobs [as] happened in 2015,” Rodrigues said, referring to losses after government cuts to the FIT three years ago.
Londoners would miss out from ministers’ increased policy focus on large-scale, centralised, green energy over small-scale, decentralised, energy sources, such as rooftop solar systems, she added. The decision was contradictory given that the public had consistently shown that they wanted solar, Rodrigues argued.
At stake is the future of the mayor’s Solar Together project, which oversees auctions where solar installers compete to offer the lowest price to a group of households who have shown an interest in the renewable energy source.
The first round of the scheme cut the cost of installations by 35% on market prices and should lead to 600 homes being fitted with solar equipment by the end of the year.
A second phase of householder applications closed on Wednesday, and the Greater London Authority hopes to rush those through before the FIT expires at the end of March 2019.
Without the FIT, payback periods would be so long they could deter people from taking up solar power, Rodrigues said.
London has consistently been the worst region in England for solar installations, a ranking that has not changed under Khan. But Rodrigues said the pro-solar stance of the mayor, who was elected two years ago, had made an impact. “The pace of change and action is radically improved,” she said.
A spokesperson for the Department for Business, Energy and Industrial Strategy said: “This scheme has been hugely successful, outstripping our predictions and generating enough electricity for two million homes. But it’s only right we protect consumers from costs and adjust incentives as costs fall.”
Kate Blagojevic, head of energy at Greenpeace UK, said: “This is another blow to the solar industry from a government that seems determined to kill it off entirely, together with the jobs it provides and all the potential benefits of a 21st century smart grid.”