The Bill & Melinda Gates Foundation has pledged $370 million and hosted a competition to come up with tomorrow's toilet technology. The foundation expects to test prototypes within three years.
Read MoreSo far, the results are interesting and rather creative:
- Harnessing microwave energy to convert waste to electricity
- Using urine to do the flushing
- Turning excrement to charcoal
"To pass the foundation's threshold for the world's next toilet," writes the Associated Press' Donna Gordon Blankinship, "it must operate without running water, electricity or a septic system, not discharge pollutants, preferably capture energy or other resources, and operate at a cost of 5 cents a day."
The need for a contest like this is not unfounded. About 2.5 billion people, 40% of the planet, do not have access to proper sanitation, and the United Nations estimates that about 1.5 million children die from lack of sanitation every year.
The winning design from California Institute of Technology transforms waste into hydrogen and electricity by using solar power.