Bill Gates awarded $100,000 prize to the California Institute of Technology for its work on a solar-powered toilet at the Reinvent the Toilet Fair, held 14-15 August at the Bill & Melinda Gates Foundation in Seattle, Washington (US).
The solar toilet looks like a conventional stall and urinal. A PV panel produces power for an electrochemical reactor, which is buried underground, that breaks down feces and urine into hydrogen gas. The gas is then stored in hydrogen fuel cells to provide a back-up energy source for night or low-sunlight use.
A continuous process recovers water, which is re-pumped to flush the toilet.
Four out of 10 people worldwide don’t have access to a flush toilet, the Microsoft co-founder wrote in a recent blog post, and sanitation problems caused by open defecation kills 1.5 million children each year.
A year ago Gates’ foundation started its Reinvent the Toilet Challenge. Its goal is to deliver a reinvented toilet for the 2.5 billion people worldwide who don’t have access to safe and affordable sanitation. To date, the foundation has raised about $6.5 million in funding for toilet technology.