Back in July, I wrote about how the Bill and Medinda Gates foundation was flushing almost $42 million into toilet research and development. You see, effective sanitation has been a public health triumph for the developed world, but the water-intensive model you are likely to use can’t easily be replicated in some parts of the developing world. As a result, sanitation often leaves something to be desired: most of all, protection from certain deadly disease like malaria. I termed this, very maturely, “Bill Gates’s Potty Obsession.”

But the Gates Foundation’s toilet-related interests extend beyond novel means of sanitation. Imperial College London, the University of Manchester, and Durham University recently became the recipients of funding from the foundation to take toilets a step further. These institutions think that, to put it bluntly, we might be able to power our homes with poop.

Researchers at these universities will be developing a prototype device that they say can harvest energy and even potable water from fecal matter (this goes well beyond even NASA’s plans to make urine into the astronaut’s sports drink). The device will work, according to a release from Imperial, thusly: “The technology is based on a porous scaffold that holds bacteria and metal nano-particles. When faecal sludge is filtered through the scaffolding these particles will react with the waste mater to generate the recycled resources. These can either be used immediately or stored for later use.” The researchers envision, in the long run, a device that can gather various types of resources: methane for energy; ammonia for fertilizer; electrolytes for energy.

The device could be used in both the developed and developing world, they contend. Said Dr. Martyn McLachlan of the Department of Materials: “In the future, we may see homes in the UK generating their own clean water, energy and fertilizer simply by doing what comes naturally to us all once or twice day. More important are the implications for developing countries, where the provision of clean drinking water is essential for supporting life and self-generated energy could be used to support economic growth.”

Eager to try the thing out? I wouldn’t hold it. A prototype reportedly won’t be ready for demonstration till 2013.

This would appear to be of a piece with what the Foundation termed the “Reinventing the Toilet Challenge” last July. It put out a wonderful video at the time, one that dove headfirst into all the wordplay that would inevitably figure in coverage of the idea.

The announcement from Imperial makes no direct mention of that particular challenge. Nor does it say the funding amount, though a document  (PDF) from the Gates Foundation last year said that it was mulling grant amounts in the ballpark of $200,000-$400,000. (Ultimately, for the Challenge, it granted $3 million to eight universities.)

It’s hard, of course, to call an idea like distilling water and energy from feces “old hat.” And yet, inevitably, some have ventured into these waters already–enough that Green Prophet was able to offer a roundup of “5 Brilliant Projects That Turn Poop Into Power” back in December. San Francisco’s reportedly interested in turning dog doo into electricity. Even students are dabbling in the poop-to-power product pipeline.

But the Gates Foundation is hunting big game here. As Frank Rijsberman, director of the Foundation’s Water, Sanitation and Hygiene Initiative, recently put it to Scientific American, he’s after a toilet so amazing you’d practically wait in line to buy it–“the iPad of sanitation,” he called it.