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Bill backs one out at Reinventing the Toilet fair


August 15, 2012

Bill Gates weighs evaluates the Toronto Toilet at the Reinvent the Toilet fair in Seattle

Bill Gates weighs evaluates the Toronto Toilet at the Reinvent the Toilet fair in Seattle

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In an effort to improve conditions for the more than 2.5 billion people worldwide with no access to safe sanitation, the Bill & Melinda Gates Foundation last year awarded grants totaling US$3 million to eight universities to reinvent the toilet. At the two-day “Reinventing the Toilet” fair held in Seattle this week, where Bill Gates was on hand with 50 gallons (189 l) of fake feces made from soybeans and rice to put the various designs through their paces, a California Institute of Technology (Caltech) team claimed first place for their solar-powered toilet.

The reinvent the toilet challenge asked teams to design a toilet that was completely self-contained and didn’t require a sewer connection, piped-in water, or outside electricity. It also had to cost less than 5 cents a day per person to operate and be easy to install and maintain.

Caltech environmental scientist and engineer Michael Hoffmann ticked all these boxes with his solar-powered toilet design, which uses a solar panel to generate electricity to power an electrochemical reactor that breaks down water and human waste material into fertilizer and hydrogen gas.

The winning Caltech toilet breaks down water and human waste material into fertilizer and hydrogen gas

This hydrogen gas can then be stored in hydrogen fuel cells as a backup power source so people can continue to relieve themselves at night and on low-sunlight days. The treated water can then be used to flush the toilet of for irrigation. Hoffman and his colleagues collected $100,000 for the design.

Taking home the $60,000 second place prize was a team from Loughborough University, whose toilet transforms feces into biological charcoal, minerals, and clean water through a process combining hydrothermal carbonization followed by combustion, which is powered by heat generated during the combustion phase of feces processing.

Loughborough University's toilet design (Photo: Bill & Melinda Gates Foundation/Michael Hanson)

The $40,000 third place prize was awarded to a University of Toronto team, whose "Toronto Toilet" uses a sand filter and UV-ray disinfecting chamber to process liquid waste and a smolder chamber, similar to a charcoal barbeque, to incinerate solid waste that has been flattened and dried in a roller/belt assembly.

The University of Toronto’s toilet design (Photo: Bill & Melinda Gates Foundation/Michael Hanson)

A $40,000 Special Recognition Award for outstanding design of a toilet interface went to a team from the Swiss Federal Institute of Aquatic Science and Technology (Eawag) and the Austrian design firm EOOS for their “Diversion” squatting toilet. This design separates feces and urine before they are then deposited in self-sealing feces containers and urine barrels ready for transport to a semi-central treatment plant where they can be processed into saleable products such as fertilizer and biogas.

The “Diversion” squatting toilet from eawag (Photo: Bill & Melinda Gates Foundation/Michael Hanson)

The grants awarded to the eight Reinvent the Toilet challengers were part of $42 million in sanitation grants the Gates Foundation awarded last year that are intended to spur innovations in the capture and storage of waste, as well as its processing into reusable energy, fertilizer, and fresh water.

The winning Caltech toilet is described in the video below.

And if anyone has some witty alternative captions to go with the main image, please let us know in the comments.

Sources: Bill & Melinda Gates Foundation, Caltech, Loughborough University, University of Toronto, Eawag

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag. All articles by Darren Quick

"Error: TOILETPAPER.SYS not found - (A)bort, (R)etry, (I)gnore?"


Bill Gates can't make up his mind when asked what dip he wants with his stool....

Brendan Dunphy

Congrats on a great headline - in the olden days, you'd have been the toast of the newsroom

Mike Hanlon

Interesting invention, but I think the old latrine does a better job, with a small fraction of the cost


Nice one mooseman. Whatever you do don't hit ignore, the resulting rash will sting more than the price you paid for the toilet.

Ross Jenkins

Good for the Gates Foundation - looks like they are trying to do things that make sense. This is a great one but still a bit too technology-heavy: solar cells, batteries, controller, and there's even a filter that looks like the ones that need new cartridges every so often. To make a difference on a global scale, it will have to be far simpler, cheaper, and needs to be done without supplies such as filters, or batteries that will only last so long. Good start, but keep working.


I thought M$oft already did this with Windows 8.


Leave it to Bill to bring S**T to the meeting.


Something from "behind the curtains" There is an Israeli company PAULEE CLEANTEC (www.ashpoopie.com) who invented a brilliant ingenious device called "ashpoopIe" which turns dog's poo sterile and smell free. In a few seconds this ash can be left anywhere with no danger or harm.

What we found out that parallel they are also developing ingenious CAT LITTER BOX which is based on same patent. More than that, the company has signed a JDA with one of the biggest international firm in order to develop those devices which hopefully will come in to the markets soon.

It seams that based on same patents (which were already allowed in the US and Europe) and some new ones, the company is working also on developing some applications regarding human waste and can fit portable toilets for boats, yachts, aviation, trains, motor caravans etc and also can be good for summer houses, livestock, kennels, animals shelters and more. What I also found out that this company won recently $110K http://www.gatesfoundation.org/Grants-2012/Pages/PAULEE-CLEANTEC-LTD-OPP1058630.aspx


http://israel21c.org/?s=toilet paulee cleantec

Does it all mean that we are going soon for better, cleaner and healthier world ?


I'd think the acquisition cost and maintainability would be criteria as well? Composting toilets are simple and cheap.




Field sanitation is a serious problem and a major health hazard. Open pit latrines contribute to disease distribution with flies and groundwater leakage. The next issue is how do you clean hands after defecation assuming there is even any TP? First person in contaminates the flush handle, etc.

The Army had a CSA-level task force looking at early OIF problems. Basically the military uses burn-out latrines in areas where dug latrines don't work well.... the burn-out latrines create their own problems. Mixing diesel, gas, and human waste then lighting it has predictable errors (resulting in medical evacuations).

These problems are magnified by the many small Forward Operating Bases (FOB) . Watch the Afghan documentary http://restrepothemovie.com

A division is roughly 20,000 folks (a small city) so physically processing the waste can be a very large problem (aside from the health risks).

These issues are not limited to poor countries. Large natural disasters (e.g. Katrina) and some areas of the US need these kinds of solutions.

JA Larson

Why do they focus on daily operating costs yet ignore the amount it costs to build these devices? Unless he plans on donating them, I can't see these impoverished people being able to buy or build.

Ed Reed

This is such an encouraging article. And it is heartwarming to see wealthy people and organizations giving to projects that will help humanity. I wonder what are the plans for producing the units for distribution and how long that might take. Now that they are designed, will it be practical and feasible to what?--give them to countries that need them? sell them? It seems the problems will begin now that the design is completed.


I would suggest an ultra low-flow toilet with an anaerobic digester.


Squat toilets should be a non-starter in this competition. They're difficult or impossible to use by many elderly people and people with bad knees and/or hips. Then there's people in wheelchairs and those who are missing part of one or both legs.

Something these high tech loos need is a bidet function to eliminate the need for toilet paper. Recycled and cleaned water should work fine for that. A solar sanitizer that exposes the water to sunlight's UV radiation and also heats it would destroy all bacteria and most viruses, including HIV. Outside a host, HIV is very easy to kill.

Gregg Eshelman

Drive a long way anyplace in Australia, and you'll find a fully self-contained answer to exactly what Bill wants by the side of all our highways - councils here have been installing these things for decades.

It does beg the question though - why'd he give away $3M instead of just looking up what he needs in Google (or Bing or whatever) ? Universities are cool and all that, but they're full of dreamy school kids. If he's actually trying to solve a problem, buying a tried and proven answer from someone with experience who knows what they're doing is significantly smarter...


re; christopher

They are looking for something better than stinky outhouses.


The title for this article should be "Bill Gates finally gives a sh#t".

Lukasz Niedojadlo

re; Gregg Eshelman

Given that squatting over a hole in the ground is how the people that the toilets are for are already relieving themselves there will be no additional problems for them.


i wonder if it stinks?

Hahn Jackson

In the Atlas Mountains in Morocco they dig a 2-4 cubic metre hole and line it with several layers of porous rock found locally. It is capped with a slab of rock and the ordinary toilets are piped into it and the bacteria which colonise the porous rock digest the waste. The only "products" required are some simple toilet pans (western or eastern design) some pipes and taps for washing. They work forever until, that is, tourists arrive and start filling them with plastic sanitary pads, tampons, make-up removal pads, condoms, super-strong toilet paper, disposable nappies, plastic razors, etc.etc.

Doug MacLeod
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