The couple’s charity, the Bill & Melinda Gates Foundation, sponsored a contest to see which university could build a toilet best suited to the needs of countries that lack sanitation infrastructure, CNN notes.
Roughly 2.5 billion people worldwide live in areas without properly functioning sewers and toilets. Disease runs rampant in such places, accounting for high levels of mortality, especially among children.
Various entries were submitted, all appearing at the foundation’s “Reinvent the Toilet Fair” held in Seattle.
The winning toilet came from the California Institute of Technology. It uses solar power to convert human waste into hydrogen and that can then be stored and used to generate electricity. Along with the title comes a $100,000 prize.
Second and third place went to toilets from Britain’s Loughborough University and the University of Toronto, respectively.
The foundation will award another $3.4 million in grants for other organizations working to develop human waste disposal technologies for emerging nations.