A toilet that uses solar power and generates hydrogen and electricity, another that makes charcoal, minerals, and water, and a third that sanitizes excrement and recovers resources and clean water: these are all inventions that are attracting funding in an international push by the Bill and Melinda Gates Fondation to produce sustainable sanitation for all.

Announcing the winners of the Reinvent the Toilet Challenge this week in Seattle, Foundation co-chair Bill Gates, said:

“Innovative solutions change people’s lives for the better. If we apply creative thinking to everyday challenges, such as dealing with human waste, we can fix some of the world’s toughest problems.”

The Foundation issued the challenge to universities a year ago: come up with new toilet designs that capture and process human waste without using piped water, sewerage or electrical connections, and convert that waste into useful resources like energy and water, cheaply.

The first, second and third prizes go to designers of prototypes that most closely meet these criteria. These are:

  1. California Institute of Technology in the US: they win $100,000 for designing a solar-powered toilet that generates hydrogen and electricity,
  2. Loughborough University in the UK: they win $60,000 for designing a toilet that produces biological charcoal, minerals, and clean water, and
  3. University of Toronto in Canada: they win $40,000 for designing a toilet that santizes feces and urine and recovers resources and clean water.

A special recognition award of $40,000 also goes to Eawag (Swiss Federal Institute of Aquatic Science and Technology) and Austrian design company EOOS for their “outstanding design of a toilet user interface”.

Harald Gründl of EOOS said:

“We have designed a toilet that works everywhere, from the slums of Kampala to a millionaire’s weekend home in the country”.

A statement from EOOS describes the innovation as the result of an “intensive exchange between Vienna and Zurich” that over the past year has produced the “diversion toilet”:

“… a squat toilet that separates urine and feces, offers clean water for hand washing and cleaning the facility, requires no sewer or water connections and can be locally produced – all for 5 cents per day per person.”

The company says they are also working on a service concept to implement the system in the longer term.

The awards are intended to reward researchers inventing new ways to manage human waste in an effort to improve human health around the world.

Teams from 29 countries showcased their inventions at the Reinvent the Toilet Fair which took place at the Foundation’s headquarters in Seattle on Tuesday and Wednesday.

Other projects include better ways to empty latrines, “user-centered” public toilets, and latrines that contain insect colonies that decompose feces faster.

Gates said all the participants share the same desire: to make a better world “where no child dies needlessly from a lack of safe sanitation and where all people can live healthy, dignified lives”.

“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,” he added.

For less wealthy nations, many serious health problems and deaths are caused by unsafe methods of collecting and treating human waste.

1.5 million children die every year because their food and water contains fecal matter.

Many of these deaths can be prevented with proper sanitation, safer drinking water and improved hygiene.

Aside from the benefit to human health, improving sanitation also makes economic sense.

Figures from the World Health Organization (WHO) suggest every dollar invested in improving sanitation yields 9 dollars in social and economic benefits, much of it from improved productivity, reduction in healthcare costs, and prevention of illness, disability and early death.

The Foundation also announced a second round of Reinvent the Toilet Grants, totalling nearly $3.4 million. These went to:

  • Cranfield University in the UK: awarded $810,000 to develop a toilet that removes water from human excrement and vaporizes it using a hand-operated vacuum pump and an innovative membrane system. The water vapor is then condensed into liquid form and can then be used for washing or irrigation. The solids are made into fuel and fertilizer.
  • RTI International: awarded $1.3 million to develop a self-contained toilet that uses a revolutionary biomass converter to disinfect liquid waste and turn solid waste into fuel or electricity.
  • Eram Scientific Solutions Private Limited of India: awarded $450,000 for their “eToilet” that is designed to make public toilets more accessible to the urban poor using an eco-friendly and hygienic design.
  • University of Colorado Boulder in the US: awarded nearly $780,000 to develop a solar toilet that focuses and concentrates sunlight to disinfect liquid-solid waste to make biological charcoal and fertilizer as a replacement for wood charcoal or chemical fertilizers.

Written by Catharine Paddock PhD