Caltech’s solar-powered toilet won the $100,000 Reinventing the Toilet Challenge issued by the Bill and Melinda Gates Foundation. The UK’s Loughborough University picked up the $60,000 second prize.

Last summer, Hoffmann, the James Irvine Professor of Environmental Science at Caltech, and his team were awarded a $400,000 grant to create a toilet that can safely dispose of human waste for just five cents per user per day. The lavatory can’t use a septic system or an outside water source, or produce pollutants.

Hoffmann’s proposal, which won one of the eight grants, was to build a toilet that uses the sun to power an electrochemical reactor. The reactor breaks down water and human waste into fertilizer and hydrogen, which can be stored in hydrogen fuel cells as energy. The treated water can then be reused to flush the toilet or for irrigation.

The challenge is part of a $40 million program initiated by the Gates Foundation to tackle the problems of water, sanitation, and hygiene throughout the developing world. According to the World Health Organization, 2.5 billion people around the globe are without access to sanitary toilets, which results in the spread of deadly diseases. Every year, 1.5 million people—mostly those under the age of five—die from diarrhea.

So, you’re one of those 2.5 billion who lack toilets in the world. You live in 5 sqm in a slum in Delhi. You’re getting ill because your water is full of coliform bacteria. What do you do?

You sit back and relax, because your knights in shining armor are here. Bill and Melinda Gates Foundation recently (some X months ago) published a request for a toilet that took no inputs and produced no output (laws of physics be damned). It seems that they didn’t quite get that (bummer, I never liked that Newton guy anyway, too many apples) .

Instead they got toilets that cost less than 3 Rs per flush (oh man, wow!) with amazing, gleaming technical contraptions that will fit perfectly well in the muddy monsoon soaked streets of your neighborhood basti.

Of course, these toilets will work great and the service and distribution network that will allow them to work for 365 days a year will be amazing, and each flush being worth a daily meal will no doubt be appreciated by its users.

Go B&MG.