Africa: Background – Reinvent the Toilet

Seattle — About the Reinvent the Toilet Fair

The Reinvent the Toilet Fair, held August 14-15, 2012 at the Bill & Melinda Gates Foundation in Seattle, Washington, showcases innovations from around the world that are creating a new vision for the next generation of sanitation. The fair aims to inspire collaboration around a shared mission of delivering a reinvented toilet for the 2.5 billion people worldwide who don't have access to safe and affordable sanitation.

The fair features the foundation's Water, Sanitation & Hygiene initiative grantees from our 2011 Reinvent the Toilet Challenge and Grand Challenges Explorations, and others whose work is aligned with efforts to reinvent the toilet.

Reinvent the Toilet Challenge – In June 2011, the foundation awarded eight universities grants of approximately $400,000 to leverage, in one year, advances in science and technology to create a waterless, hygienic toilet that is safe and affordable for people in the developing world. These grantees are eligible for the Reinvent the Toilet Challenge awards that will be announced August 14, 2012. Awards include : First Prize: $100,000; Second Prize: $60,000; Third Prize: $40,000.

Reinvent the Toilet Challenge aims to:

  • Address the failures of the 18th-century toilet, which is not meeting the current needs of 2.5 billion people who lack access to sanitation
  • Devote funding and attention to the need for a new toilet
  • Generate innovation among a wider research and development community
  • Support upstream research and development of a toilet that:
  1. Is hygienic and sustainable for the world's poorest populations o Has an operational cost of $0.05 per user, per day
  2. Does not discharge pollutants, but instead generates energy and recovers salt, water and other nutrients
  3. Is designed for use in a single family home 
  • Create a toilet that does not rely on water to flush waste or a septic system to process and store waste
  • Create a toilet that is the basis for a sanitation business that can be easily adopted by local entrepreneurs living in poor urban settings  ï‚· Raise awareness about this research by publishing scientific papers in journals and articles in various media outlets

Grand Challenges Explorations – These grants were awarded in April and November 2011. Each grantee received $100,000 to develop components of, or complete, non-networked sanitation solutions in one of four thematic areas:

  • Latrine pit and tank emptying
  • Recovery of energy from fecal sludge for safe and affordable treatment and disposal
  • Sanitation solutions for areas challenged by an abundance of water
  • Easy-to-clean, attractive, and affordable latrine and squatting platform technologies

Other Exhibitors – These are foundation grantees and partners working on projects aligned with reinventing the toilet. Their investments range from $750,000 to $5 million. Exhibitors are showcasing a range of work, including latrine emptying solutions, user-centered designs for public toilet facilities, and insect-based latrines that decompose feces faster.

Reinvent the Toilet Challenge Grantees

A toilet that converts human waste to fuel gas – Delft University of Technology, The Netherlands

A toilet system that applies microwave technology to transform human waste into electricity. The waste will be gasified using a microwave-induced plasma. This process will yield synthesis gas (syngas), a mixture of carbon monoxide and hydrogen. The syngas will then be fed to a solid oxide fuel-cell to generate electricity.

Diversion for safe sanitation – Participating organizations: Eawag: Swiss Federal Institute of Aquatic Science and Technology; EOOS , Switzerland

A functional model of a urine-diverting toilet that recovers water for flushing. The urine and feces will be safely transported to a decentralized processing center. The water used for cleaning will be recycled by a gravity-driven biological membrane.

A toilet that sanitizes feces and urine to recover resources and energy –  University of Toronto, Canada

A technology for treating solid waste streams through mechanical dehydration and smoldering (low-temperature, flameless combustion) that will sanitize feces within 24 hours. Urine will be passed through a sand filter and disinfected with ultra-violet light.

A urine-diverting combustion toilet – National University of Singapore, Singapore

A toilet that uses biological charcoal (biochar) to dry and combust feces. The heat generated will be used to extract water from urine by boiling it under pressure. The system can be fitted with activated carbon and exchange resin to recover highly purified water.

A community bathroom block that recovers clean water, nutrients, and energy – University of Kwazulu-Natal, South Africa

A toilet system that can safely dispose of pollutants and recover materials such as water and carbon dioxide from urine in community bathroom blocks. The system will separate the urine from the feces and extrude the feces into thin strands for faster drying and stabilization.

A toilet that produces biological charcoal, minerals, and clean water – Loughborough University, United Kingdom

A toilet that transforms feces into a biological charcoal (biochar) through hydrothermal carbonization (decomposition at high temperatures without oxygen and in water) of fecal sludge. The proposed system will be powered from heat generated by combusting the produced biochar and will be designed to recover water and salts from feces and urine.

A solar-powered toilet that generates hydrogen and electricity – California Institute of Technology, USA

A self-contained, solar-powered toilet and wastewater treatment system. A solar panel will produce enough power for an electrochemical reactor that is designed to break down water and human waste into hydrogen gas. The gas can then be stored for use in hydrogen fuel cells to provide a backup energy source for nighttime operation or use under low-sunlight conditions.

A sanitation system that converts human waste into biological charcoal – Participating organizations: Stanford University and the Climate Foundation, USA

A self-contained system that pyrolyzes (decomposes at high temperatures without oxygen) human waste into biological charcoal (biochar). After the fair, the system will be shipped to Nairobi to process two tons of human waste daily, at a facility located in the slums.

About the Bill & Melinda Gates Foundation's Water, Sanitation & Hygiene Initiative

The foundation's Water, Sanitation & Hygiene (WSH) team is working with partners to develop sustainable sanitation services that work for everyone, including the poor.

The Reinvent the Toilet Fair showcases some exciting investments in science and technology.

These grants are funding innovations in a range of improved toilet technologies–based on fundamental engineering processes–for the safe and sustainable management of human waste.

Technology is not the only thing that is needed to meet the sanitation challenge. Behavior change and encouraging markets and governments to provide sanitation products and services to those in need must also be part of the solution. Our policy and advocacy work encourages sanitation policies and investments that work for the poor. We focus our efforts in sub-Saharan Africa and South Asia, where the burden of unsafe sanitation is greatest.


Bill & Melinda Gates Foundation (Seattle)

Africa: Background – Reinvent the Toilet

The Reinvent the Toilet Fair, held August 14-15, 2012 at the Bill & Melinda Gates Foundation in Seattle, Washington, showcases innovations from around the world that are creating a new vision for the next generation of sanitation.