London's hidden gas plant which could heat and power the future

A 26m refit of a power station beside Smithfield market has made E.ON's Citigen the largest urban combined heat and power plant in the UK

The beautiful, listed facades of the Port of London Authority and the Central Cold Store, which once held animal carcasses from Smithfield market opposite, stand as a reminder of London's industrial and commercial past.

But behind these brick walls in the heart of London is a hidden power station that could resolve how the UK heats, cools and powers business of the future.