fuel-cell-gets-the-power-out-of-poo

http://www.abc.net.au/radionational/programs/scienceshow/fuel-cell-gets-the-power-out-of-poo/5307514

To treat wastewater  takes  about:1,800 kilojoules. (half a kilowatt hour per metre cubed)

The wastewater itself contains about : 7,600 kilojoules of energy in each metre cubed