Reinvent the Toilet Challenge

Strategy Overview


Researchers at the California Institute of Technology (Caltech) have built a toilet that uses the sun to power an electrochemical reactor.

About the Reinvent the Toilet Challenge

In 2011, the Water, Sanitation & Hygiene program initiated the Reinvent the Toilet Challenge to bring sustainable sanitation solutions to the 2.5 billion people worldwide who don’t have access to safe, affordable sanitation.

Grants have been awarded to sixteen researchers around the world who are using innovative approaches—based on fundamental engineering processes—for the safe and sustainable management of human waste. In addition to these Reinvent the Toilet Challenge (RTTC) grants, we have made a range of other investments that are aligned with reinventing the toilet, and we are continuously seeking to expand our partnerships on this challenge.

Loughborough University has developed a user-friendly, fully operational household toilet system that transforms feces into biochar through the hydrothermal carbonization of fecal sludge.

The Reinvent the Toilet Challenge aims to create a toilet that:

  • Removes germs from human waste and recovers valuable resources such as energy, clean water, and nutrients.
  • Operates “off the grid” without connections to water, sewer, or electrical lines.
  • Costs less than US$.05 cents per user per day.
  • Promotes sustainable and financially profitable sanitation services and businesses that operate in poor, urban settings.
  • Is a truly aspirational next-generation product that everyone will want to use—in developed as well as developing nations.

Reinvent the Toilet Challenge: China

In August 2013, the foundation announced the Reinvent the Toilet Challenge:China.  The foundation will invest US$5 million to support Chinese investigators to drive research, development, and production of the “next generation toilet.”

This China toilet challenge is the first effort targeted to a specific country and is a testament to the research and development capabilities in China.

University of Toronto Sanitation Now!: This is a 10-user on-site sanitation appliance that collects, rapidly disinfects, and recovers nutrients from human waste.

Reinvent the Toilet Challenge: India

In October 2013, the Department of Biotechnology (DBT) under the Ministry of Science and Technology of the Government of India and the Bill & Melinda Gates Foundation in collaboration with India’s Biotechnology Industry Research Assistance Council (BIRAC) launched the Reinvent the Toilet Challenge:India.  This partnership will support sanitation research and development projects conducted by Indian individuals and organizations to extend affordable sanitation services to poor communities. 

The Reinvent the Toilet Challenge:India is part of a broader partnership with the Gates Foundation and BIRAC to cooperate on the: 

  1. reduction of maternal and child mortality and morbidity
  2. scientific and technical solutions for infectious diseases
  3. strengthening India’s scientific translation capacity
  4. scientific and technical advances related to agriculture
  5. scientific advancement in food and nutrition.

About the Reinvent the Toilet Fair

In August 2012, the Bill & Melinda Gates Foundation hosted a two-day Reinvent the Toilet Fair at the foundation’s headquarters in Seattle, Washington. The fair showcased sanitation projects and Reinvent the Toilet Challenge prototypes. The fair brought together participants from 29 countries, including researchers, designers, investors, advocates, and representatives from the communities who could ultimately adopt these innovative approaches to sanitation.

In March 2014, a second Reinvent the Toilet Fair was held in New Delhi, India, co-hosted by the Government of India’s Department of Biotechnology and the Bill & Melinda Gates Foundation, with the support of India’s Ministry of Urban Development. India is uniquely positioned to be a global leader in the development of new sanitation technologies and a range of other innovative approaches to achieve sustainable gains in sanitation in India and abroad. The Reinvent the Toilet Fair: India aimed to stimulate discussion and spur partnerships to bring safe, affordable sanitation to the 2.5 billion people who lack access.

The Eawag/EOOS Blue Diversion, a next-generation urine diversion dry toilet that provides water for flushing, hand washing, and personal hygiene, is being field tested in Uganda. Photo © Eawag/EOOS

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