Toilet of the future

‘Toilet of the future’ solves global issues

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.

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.

Hoffmann’s proposal—which won one of the eight grants given—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.