The toilet that doesn’t need electricity, sewer or water

There are a great many reasons why the toilet should be reinvented. First among them is the huge amount of water we use for flushing them – at a time when there are droughts in many parts of the world, it is shortsighted and wasteful. Bur there are other reasons. It is wasteful to flush away urine and feces, when they can be used to generate biogas, or dried and mined for minerals. The people who are reimagining the sanitation industry for the 21st century call them ‘toilet resources’.

It is not that – at a time when we can send people into space – there is a shortage of new models that address the $223 billion challenge that unsafe sanitation poses in our world. There are a lot. Today, though, I wanted to talk about the I-throne, which was developed by a brilliant woman who worked with NASA in 2009 on how to recycle water for space agriculture. 

Her idea wasn’t used in that project, but she kept it in the back of her mind, and worked on a prototype in her kitchen because she had no resources. In 2014, she pitched an early version at MIT’s Water Innovation Prize and the MIT IDEAS Social Innovation Challenge. 

Her change:WaterLabs eventually received seed funding to explore the idea from IDEAS and the MIT PKG Center, making it possible to access lab facilities for early testing. That support was a game changer, she says, “because you start to have doubts about whether what you’re doing is possible, and when some other entity like MIT takes a bet on you, you start to believe it yourself.”

That is especially so when you are completely redesigning the notion of toilet and sanitation system, as Yousef was.

“Our low-cost, portable toilets use a simple membrane to rapidly evaporate 95% of sewage without using any type of energy. This innovative technology provides homes with a working toilet, without the need for power or plumbing. The compact, contained, stand alone units can be dropped into any space quickly, and the ‘self-flushing’ technology works while being completely waterless and environmentally safe.” The iThrone only needs to be emptied once or twice a month.

The toilet uses evaporative pouches that dehydrate liquid and solid waste daily so only dried solids remain inside and are hygienically contained. Used pouches can be swapped for clean pouches, with the shrink-wrapped stuff disposed of in a landfill, processed at a treatment plant, or used to make fertilizer or fuel depending on the location.

In 2020, the i-Throne moved to the field – specifically to a neonatal clinic at a hospital in Kiboga, Uganda where the two waterless, standalone bathrooms offered a cleaner and more private alternative to the pit latrines that are standard in the region.

The toilets were used by about 400 people per week in Uganda before the project was cut short by Covid-19. Yousef says they proved safe, with minimal odor and no leakage, meaning they could be placed in crowded areas near people and thus solving the problem of such version as composting toilets. The toilets reduced daily waste volumes so much that they didn’t need to be serviced for weeks at a time and user feedback was overwhelmingly positive.

Although travel restrictions have put other iThrone pilots on hold, change:WATER Labs has received funding from the Bill and Melinda Gates Foundation, the United Nations Development Program, and the Turkish government to install its toilets in refugee communities in Turkey later this year, says MIT News.

Private companies have also expressed interest, including two large construction contractors looking to put iThrones in low-income homes in Central America, and two Indian companies seeking to put iThrones in port-a-potties and on transportation and maritime equipment.

Yousef says that shows the large global need and pent-up demand for better sanitation options.

“We need new solutions that contain and eliminate human waste while also reducing the amount of water that gets consumed, preventing pollution. We solve all of that.”

There is a particular focus on women and girls because when they lack such facilities in or near their homes, they face a higher risk of sexual assault, Yousef says. And girls who don’t have private toilets at school often skip classes when they have their period. “Girls make all sorts of compromises to get through a day of school,” she told Business Insider in 2019. “They don’t drink. They don’t eat. They go to school tired.” Eventually, some drop out.

Yousef said many potential investors she talks to are surprised to hear about these issues — or even that people lack toilets at all. “Oftentimes, they’ve never seen a place in the world where people don’t have toilets,” she said. “They immediately ask me: ‘Is this a toilet I can use at Burning Man?’”

The Bill and Melinda Gates Foundation has been running a Reinvent the Toilet Challenge since 2011 that focuses on designing low-cost toilets that don’t need connections to the electrical grid, water supply or sewers. Winning ideas in 2012 included a solar-powered toilet that generated hydrogen and electricity, a toilet that produces biological charcoal, minerals and clean water, and a toilet that sanitized feces and urine and recovered resources and clean water.

“Several designs that debuted at the Reinvented Toilet Expo in 2018 are now commercially available,” the Foundation says. “These toilets work using internal combustion and chemical treatment systems, and they can be set up in areas that are hard to reach with traditional infrastructure. They can deliver the same benefits as toilets connected to sewers, plus wholly new benefits that include the removal of human pathogens and generation of usable water and electricity.”


The iThrone Evaporative Toilet Answers The Call For Healthy Cities. Forbes, Sep 29, 2019

An innovative toilet called the ‘iThrone’ shrinks and dehydrates poop — no plumbing or power required. Creating Hope in Conflict: A Humanitarian Grand Challenge, Oct 24 2019

Improving sanitation for the world’s most vulnerable people. MIT News, Feb. 23, 2021

And the winners of the reinvent the toilet challenge awards are…?  Gates Notes, Aug. 14, 2012