Well, this is interesting:
"Every now and then we hit upon a story which really feels like a glimpse into the desired future. The idea of using microbes to simultaneously clean the water supply and generate power is almost too good to be true. But it's in the labs now, and it's getting closer to the real world every day."








I had a microbiology professor in nursing school who used to do that kind of research! I love stuff like this.
The power levels are impractically low, for a power source... They're up to 146 milliwatts/m2, hoping to eventually get to 1 W/m2. This makes solar power look incredibly good (very cheap cells can easily hit 100 W/m^2 in sunlight, expensive high performance cells hit about 3 times that).
Expensive high performance cells don't also product potable water as the waste product. Producing potable water is, itself, usually an energy/land intensive process.
Potable water? This fuel cell is going to remove nitrate, phosphate, heavy metals and the other things that make sewage what it is? I think not.
Thermal depolymerization may be a superior method for recovering energy from sewage solids (and municipal solid waste, and yard waste, and non-recyclable office paper, and a host of other things). Unless the cost of these microbial fuel cells can be brought way down, they will not produce enough energy to pay for their construction. If money would be better spent putting a dome over the sewage-treatment plant (to keep it warmer in winter) and covering it with photovoltaics or solar-dynamic generators, then we should let the bacteria do their work in the dark and out of the circuit.
Very disappinted to see the kind of comments posted. when will people learn that all great things began small. as far as my eperience in microbial power goes, it has the potential to be the cheapest form of power. I strongly believe its not a question of If. Its only when.