The Sutton Decentralised Energy Network was set up in 2016 to provide low-carbon water to homes at an estate in Hackbridge.
It’s failed to make any money, and people at the New Mill Quarter have reported consistent outages.
The report says questionable assumptions were made, and delegating authority for it was “misguided” for such a new project.
The council says they welcome the findings, and they will strength SDEN’s board and their scrutiny of the project.