A leading water company is celebrating a new type of bottom line - the generation of renewable energy from customers' poo.
Thames Water said it was flushed with success after saving £15 million last year in electricity bills by generating renewable power from the poo produced by 13.6 million customers.
The company said it met 14% of its power needs from either burning sewage sludge or methane derived from it in 2008/9.
Under the scheme, power is generated either by drying sewage into blocks of "poo cake" which is then burnt to generate power or through anaerobic digestion where the methane from sewage sludge is burned to create heat.
The company said once sewage sludge has been used for electricity, it is offered to farmers for use as fertiliser or to developers as landscaping material or soil improver.
Last year, it said, the firm put 100% of its sewage sludge to beneficial use, it said, sending none to landfill.
Dr Keith Colquhoun, Thames Water climate change strategy manager, said "poo power" and other renewable energy sources were helping make "significant" progress towards its goal of cutting greenhouse gas emissions by 20% on 1990 levels by 2020.
He said: "There's no polite way of saying this but what we produce - our poo - isn't simply waste, it's a great source of energy.
"That's good news because we treat 2.8 billion litres of sewage every day at our 349 sewage works.
"The solids in sewage have a high calorific content that we use to generate electricity."
