Bill Gates Funds Solar Toilet that Recycles Water, Generates Energy

The practice of open defecation and lack of sanitation in developing nations kills 1.5 million children under the age of 5 every year, according to philanthropist Bill Gates.

So Gates and his wife, Melinda, are devoting $6.5 million to research and development project to reinvent the toilet for countries that lack the infrastructure to use the sort widely available in established nations.

This week, the Gates Foundation awarded $100,000 to a solar-powered design from the California Institute of Technology, as part of its "Reinvent the Toilet Challenge."

The self-contained design used a solar panel to run an electrochemical reactor that breaks down feces and urine, converting it into hydrogen gas that can be stored in fuel cells as a back-up energy source. The water in the system is recovered and recycled for future flushes.

A prototype of the solar toilet designed by researchers from the California Institute of Technology. Photo courtesy of Gates Foundation

"Many of these innovations will not only revolutionize sanitation in the developing world but also help transform our dependence on traditional flush toilets in wealthy nations," Bill Gates told Reuters.

The Gates Foundation has so far committed $370 million to the problem of sanitation and hygiene issues. The organization has given out more than $26 billion in grants since the technology entrepreneur turned toward philanthropy in 1994.

To be eligible for the toilet challenges, the designs had to meet these criteria:

• Operates without connections to water, sewer or electricity
• Removes pathogens from human waste while recovering valuable resources like energy and fertilizer
• Costs less than 5 cents per user, per day

For more on the Gates Foundation’s contest, check out this Grist article: