In response to the 2015 earthquake in Nepal, Aerosan offered its services to local NGOs and it was decided that waste-to-value systems applied to public toilets in the major urban centers was the approach we should take. With the assistance of the Bill & Melinda Gates Foundation, we were able to build our first pilot project. Since then, with the support of Grand Challenges Canada, Aerosan has established a public toilet social enterprise in Nepal, the Aerosan HUB, that converts toilet waste into renewable energy. 

The Model



Aerosan’s model is built around the mission to provide sustainable and equitable sanitation solutions for urban settings in Nepal. By incorporating technological & socio-economic solutions, Aerosan aims to increase demand/attractiveness of public toilet facilities for men and women, increase management/maintenance incentives for sanitation workers, and decrease environmental impact of human waste.  Our model is a public private partnership between a local NGO and the municipality in question. The land around the toilets is owned by the municipalities and they attract small businesses and cafes, at a reduced rent, and often build facilities for them.


An anaerobic digester is built on-site that produces enough renewable energy (biogas) to serve the surrounding cafes who currently use LPG (USD15/cylinder of 14kg), thus lessening dependency on expensive imports of fossil fuels. The café uses approximately 1.5 cylinders/week.The digester is a local design, built within a month by contractors who have experience in this field. The inoculant is animal dung and within a few days the digester is switched to faecal sludge and, where available, kitchen waste. It is estimated that the digester, when fully operational, will produce the equivalent of a half tank of LPG per day (approx. 300 megajoules (Mj), even though biogas produces 25 % less energy than LPG and burners are 25 % less efficient). The next step is to install solar panels on the toilet roof to supply lighting and power points for mobile phone charging.

These simple technological applications, applied to all public toilets, have a significant effect on:


  • The environment - by lessening dumping in rivers

  • Health - since the disease profile, especially for children, is extremely high in Nepal due to open defecation and the soiling of the main water source

  • Safety – a well-lit and clean toilet complex is especially attractive to women and children

  • Cost of operations – the use of solar energy since mains electricity is expensive

  • Renewable energy production – this will lessen dependency on expensive, imported LPG

  • Local small businesses – cafes can operate on a much less expensive fuel source


Equally important are the issues of sustainability and the difficulties of the sanitation workers to earn a living wage relying only on customer entrance fees. Aerosan’s solution to address these two issues is the generation of social capital in favour of the sanitation workers. The sanitation workers, who are retained by the municipalities, are at the lowest level of the caste system (Dalits, Harijan or untouchables). They live in un-serviced informal settlements around the cities, in which living conditions are amongst the worst in Nepal. There are two steps to this process:


Improve working conditions and financial well-being of the sanitation workers: we assist increasing revenue streams for workers, for instance, they receive a portion of the revenue from sale of biogas and the sale of hygiene products. 


Set up a sanitation workers' cooperative to empower members and implement social support services - this is done in partnership with the Independent Sanitation Workers' Group (ISWG). Again with the support of Grand Challenges Canada, we are investing the establishment of a formal workers' cooperative. The uses of the investment are twofold. On the one hand the cooperative can use as a start-up for a cleaning business that could offer cleaning services to larger businesses, hotels, etc.. On the other, the fund can be used to upgrade communal facilities in the informal settlements in which the sanitation workers live. Aerosan and the local NGO would assist in this process.

Gender Inclusive Design & Hygiene Awareness

Aerosan is aware that women in Nepal (as in other countries) are disproportionately negatively affected by the lack of sanitation facilities (known to abstain from eating or drinking to avoid having to go to unclean toilet facilities). Providing gender-inclusive access to sanitation facilities and employment is at the core of Aerosan’s strategy:


  • We involve women in decision-making for the design of toilet facilities.

  • We ensure employment of female sanitation workers.

  • With our partners, we invest in campaigns to increase awareness of hygiene for women & children, menstrual hygiene, and family planning on site & in the community. 

  • We monitor the impact on women and children


Aerosan Hub Pilot

With the support of Grand Challenges Canada, we were able to implement our first Aerosan HUB public toilet system at Ratna park in Kathmandu. Our Aerosan HUB pilot project consisted of three major interventions: a biogas plant, gender-friendly renovations, and a cleaning compliance program. The results have been extraordinary.

Moreover, our ANAEROBIC DIGESTER now produces enough fuel for up to sixteen hours a day for cooking at the tea shop (6m3/day), which is significantly above the projections. This prevents more than 50 tonnes a year of waste being dumped into the rivers

Our Plans