Britain should generate more energy from sewage in order to cut water bills and help save the planet, water regulator Ofwat has said. Enough extra electricity could be generated to power all the homes in Manchester if water companies exploited the underused energy potential of sewage, analysis by one company suggests. Ofwat on Wednesday cited the old adage that “where there’s muck there’s brass” as it unveiled plans to encourage water companies to make greater use of “bioresources”, or treated sewage. Many waste water companies already use anaerobic digestion plants where bacteria breaks down sewage and creates ‘biogas’, which can be fed into the gas grid or burnt to generate low-carbon electricity. Ofwat said it was bringing in changes to “unleash innovation and efficiencies” in the treatment of sewage and that “bill payers could benefit” as a result. Analysis by company Veolia suggests that only half the potential for energy from sewage is currently being exploited. It calculates that the UK generated 846 gigawatt-hours (GWh) of power for sewage in 2015, enough to provide electricity for about 260,000 homes – more than than the size of Manchester. However using more advanced technologies, and increasing the proportion of sludge that is turned into biogas, could more than double this to 1697 GWh per year, it estimates.