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UK-based Loowatt waterless toilets turn human waste into biogas and fertiliser. Photograph: Loowatt
UK-based Loowatt waterless toilets turn human waste into biogas and fertiliser. Photograph: Loowatt

Waterless toilets turn human waste into energy and fertiliser

This article is more than 9 years old

A number of innovative projects have set out to capture the valuable nutrients available in human faeces and make a profit from poo

You might have heard of flying toilets. I’m not talking about the well-equipped loos available to us as we soar 39,000 feet into the sky, complete with soft loo roll, airline-branded soap and hand dryers. No, flying toilets are the outcome of people forced to go to the loo in a bag before throwing it into the streets because no better option exists.

According to the UN, 2.5 billion people in the developing world lack what many of us take for granted - access to a toilet. As a result, human faeces ends up on the roadside, in drinking water and eventually in people’s stomachs. The outcome is diarrhoea. Second only to pneumonia in its destructiveness, diarrhoea kills more than 4,000 children a day (pdf), yet gets a fraction of the attention and funding given to the likes of cholera, TB and measles, says Rose George, author of The Big Necessity.

George suggests that “waste” is actually a misnomer since human faeces is an inexhaustible source of valuable nutrients. The idea of value when it comes to excretion may be hard to grasp for some, but in parts of the world where access to decent sanitation is limited and opportunities for generating income are slim, there is an urgency that drives the creation of opportunities.

Take Sanergy, a Kenyan-based enterprise building a network of low cost, hygienic waterless toilets in east Africa’s urban slums. For a $500 one off payment, Fresh Life Toilets are franchised to residents, who operate them as businesses by charging a small fee to users.

Sanergy collects the waste and converts it into nutrient-rich organic fertiliser which is then sold on to Kenyan farmers. To date, Sanergy has launched 555 toilets to a network of 270 Fresh Life operators serving 25,000 people a day while safely removing more than seven tonnes of waste from communities daily.

Sanergy provides waterless toilets to impoverished communities in east Africa. Photograph: Sanergy

Uncertain about an organisation profiting from poo? Consider this: 74% of Kenyans use traditional pit latrines - the sanitation problems of which, if badly maintained, have been well documented - and they usually have to pay. Likewise, the cost of emptying these pits can be high.

In turn, the franchise provides income for local entrepreneurs who can access direct financing from a local microfinance bank to get started. Most importantly, Fresh Life Toilets are addressing an immediate need for better sanitation, reducing rates of diarrhoea at very low cost to the community.

According to co-founder David Auerbach, not using water makes Sanergy possible:

Waterless toilets offer a solution that ensures waste is concentrated, which enables Sanergy to process the waste into valuable by-products with greater efficiency. In an area where water is expensive and a limited resource, waterless toilets are a cost-effective solution.

Like Sanergy, UK-based Loowatt has also developed a hygienic waterless toilet system, although this one also generates energy. The odourless Loowatt toilet uses a sealing mechanism to wrap human waste in a biodegradable liner which is pulled through the sealer when the toilet is flushed. The “cartridge” is then emptied periodically into an anaerobic digester, where the waste and biodegradable liners are converted into biogas and fertiliser.

Loowatt’s waterless, energy-generating toilet. Photograph: Loowatt

Since 2012, Loowatt has been rolling out its sanitation system at its pilot project in Antananarivo, Madagascar. There, a public toilet is linked to a micro-scale digester which provides energy onsite, although as the project expands the toilets will be linked to larger digesters operated by the local government or private operators. Using this model, the Loowatt team is working on toilet solutions for disaster relief.

Woo Woo is a London-based company that installs dehydrating toilets for UK clients without access to mains sewerage, such as allotments. With Woo Woo loos, no extra materials are required since the design enables sunlight and wind alone to turn human waste into a compost-like material.

“The idea that you could solve sanitation issues with a water-driven toilet is hilarious to me,” says Woo Woo founder James Young. “It’s not going to happen, and that’s just based on water supply. After that you have to build the methods of getting the waste away, and treating it. If someone can crack the waterless toilet by making it affordable and aspirational to everyone, it’s going to make hundreds of millions of lives better.”

Disappointingly, national governments and international organisations are failing populations by not realising the far-reaching potential of waterless toilets. These innovative projects are setting an inspiring example - without support, however, there’s a danger they will remain a mere plop in the ocean.

This article was amended on 20 November. Sanergy’s Fresh Life Toilet unit costs $500, which is a one-time payment only and not every year as previously stated.

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