NPR for Northern Colorado
Play Live Radio
Next Up:
Available On Air Stations

No Water, No Problem For CU-Boulder's New Solar Toilet

University of Colorado Boulder
CU-Boulder postdoctoral researcher Tesfayohanes Yakob, left, and research engineer Dana Haushulz are shown here with a novel solar-thermal toilet developed by a team led by CU-Boulder Professor Karl Linden

The University of Colorado Boulder has created a solar-powered toilet that will soon be unveiled in India. Yes, a solar-powered toilet. While a toilet powered by the sun sounds pretty humorous, there’s a real need for such a thing around the world.

The self-contained, waterless toilet was built and designed by CU with a $777,000 grant from the Bill & Melinda Gates Foundation and its “Reinvent the Toilet Challenge [.pdf].”

The fact that there’s no water leads to the part where you need the sun. The toilet uses eight parabolic mirrors and fiber optic cables to focus the sun’s energy into a reaction chamber. Reaching temperatures over 600 degrees, the chamber treats human waste and produces what’s called char.

“Biochar is a valuable material,” said CU team lead Karl Linden, a professor of Environmental Engineering. “It has good water holding capacity and it can be used in agricultural areas to hold in nutrients and bring more stability to the soils.”

40 percent of the world’s population lacks adequate sanitation facilities. As NPR’s Shots noted when they wondered why the Gates Foundation was buying fake poop, “in many places that lack sanitation, people also don’t have access to water or power.” The foundation says that lack of access is having disastrous consequences both environmentally and from a public health standpoint.

“The great thing about the Gates Foundation is that they provide all of the teams with the resources they need,” Linden said in a statement. “The foundation is not looking for one toilet and one solution from one team. They are nurturing unique ideas and looking at what the individual teams bring overall to the knowledge base.”

The World Health Organization says using innovative resources like a solar toilet can also have positive economic benefits. They say improved sanitation provides up to $9 in ‘social and economic benefit’ for every $1 invested.

Linden’s team is applying for phase two of the Reinvent the Toilet grant program to expand their current work.

Related Content