Used cooking oil from SE1's two NHS hospitals is being turned into biofuel for London taxis.
Each month Guy's and St Thomas' NHS Foundation Trust supplies around 400 litres of used oil to Uptown Oil, whose King James Street base is almost equidistant from both hospital sites.
The cooking oil is then blended to make biofuel for taxis and generators used by local businesses.
"We wanted a local solution for reprocessing the oil so it didn't go to waste," said Ed Van Reenen, contract sustainability manager at Guy's and St Thomas'.
"It's good for us as it reduces waste disposal costs and lowers the risk of drain and sewer blockages, and it benefits London taxis because it provides a very low carbon fuel."