Researchers reveal what the UK could learn from Nepal's uptake of toilet-linked anaerobic digesters

Overcoming the public’s squeamishness when it comes to turning poo into power, or really doing anything other than flushing domestic toilet waste than into the ether, never to be seen again, presents an ongoing challenge for scientists.

But, according to a new study by the University of Stirling, this challenge is not insurmountable and learning lessons from other countries on successful uptake of waste-to-biogas initiatives could hold the key to replicating such success in the UK.

Looking at the example of toilet-linked anaerobic digesters (TLAD) in Nepal, they believe their insights can support decision-makers to ‘understand and overcome the barriers to uptake of new technologies designed to reduce impact on the natural environment’.

TLADs see home toilets connected to an anaerobic digester – airless units in which bacteria breaks down organic matter – which then converts the waste into biogas for use as a clean-cooking fuel, and fertiliser to improve soils.

Conducting in-depth interviews in Nepal, where TLAD adoption is high, they found that not only did TLADs help improve home sanitation, indoor air quality and use of resources, but rural householders were able to overcome their cultural and religious objections around purity and pollution.

Explaining further, Natalie Boyd Williams, a PhD researcher in the division of Biological and Environmental Sciences, said: “We found that uptake was high where there was one risk taker who led the way. For example, in one village, one former policeman, who said he didn’t care what people thought, adopted the unit – and within a year most of the villagers had their own.

“This also happened because people could go into his house to see how it worked. Demonstration was another important pathway to adoption, so people could see and understand how it functioned.

“Being able to see and understand the benefits was also very important. People were worried it would make their home smell, or be unhygienic, but they were able to see that wasn’t the case. The benefits began to outweigh their opposition.”

Continuing Boyd Williams outlined that while there had been progress on anaerobic digestion in the on an industrial scale, a focus on smaller scale biogas units, which still have huge potential to contribute to the circular economy, was lacking.

She said: “I’ve seen potential plans for blocks of flats that have underground shared biogas units. And smaller scale biogas units could be used locally across the UK, for instance for community energy projects, like those which the UK government had greater support for in the past.

"But, at the moment, there are policy barriers to digesters here.”

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