Transport for London has said it is committed to diversifying its energy supply through the use of renewables but stressed that solar must represent “the best value for money” if it is to be installed.

The capital’s public transport provider has faced criticism for a sluggish uptake of on-site renewable energy generation and the two front runners to replace Boris Johnson as London mayor in May have both unveiled ambitious plans to stimulate solar in the capital.

Conservative candidate Zac Goldsmith has said he would make TfL use locally-generated renewables wherever possible, while Sadiq Khan unveiled plans last Friday to install solar on as many TfL-owned rooftops as possible.

TfL owns extensive land in London, including all 270 stations which make up London’s Underground network as well as other offices, depots and bus terminals. In total, the Mayor’s office states TfL own 683 sites within Greater London.

Speaking to Solar Power Portal, TfL’s planning managing director Richard De Cani said that the body was committed to achieving targets set by the mayor of a 60% reduction in CO2 emissions by 2025, and that renewables had a role to play in that.

“One way we aim to do this is by diversifying our energy supply, using low carbon and renewable energy sources, as well as using energy efficiency measures.

“We always consider how we might best use renewable elements such as solar panels in our new projects, as we have at West Ham bus garage, but the challenges that some of our operational environments present mean that it is not always possible,” De Cani said.

De Cani also said that any work conducted on a TfL property would require a business case “that represents the best value for money”. One such way the organisation has reduced installation costs has been to integrate solar deployment with other planned work such as roof repairs, as has been the case at Paddington station and Northfields Train Crew Accomodation.