Behind one group's plan to turn human waste into electricity
"I wake up at 5:30 in the morning to go to the fields to relieve myself."
This call of (and deposit in) nature was something Anoop Jain heard about over and again while doing community health surveys in the village of Sukhpur in Bihar, India's poorest state. He found it "ridiculously alarming." Around 90 percent of the community was defecating outside--and they were taking long, sometimes dangerous walks to go do it.
Now, multiply the problem. In India, according to UNICEF/World Health Organization 2010 estimates, 626 million people, over half the population, has no access to toilets. To put that in context, that's more than twice the population of the United States, all relieving themselves outside. At the same time, there's the parallel issue that over 400 million people in India live without electricity. It's a devil of a problem with two horns.
But as the children's book teaches us, everyone poops. That crude reality, if properly contained and converted, may also prove to be a renewable resource. This is the idea behind the Humanure Power Project, an effort led by Jain, an environmental engineer turned grad student, and a group of three other Tulane University students, who are combining existing technologies to tackle both the sanitation and power crises. Applying a $30,000 award recently won in Dell's Social Innovation Challenge, Humanure will build community blocks of toilets that convert human waste into energy, charging 12-volt batteries for household use.
Here's how it works: human waste, like any other organic waste, consists of carbon and hydrogen bonds. The team is building blocks of twenty toilets (ten for men, ten for women) that all feed together into a closed, oxygen-free biogas digester. Over twenty to forty days and in that anaerobic state, bacteria break down the waste and create two byproducts: fertilizer and a high-methane bio-gas. Like other gas, the methane can be combusted and used to fuel a generator, which in turn creates electricity. This, Jain clarifies, is not a new development -- Humanure's partner Sulabh International has been building generator toilets, with established safety protocols, for years. Energy from those toilets is regularly piped into homes to power appliances like stoves. But for villagers living off the grid, there has not yet been a way to transport home the energy produced by the generators.
Humanure is solving the distribution problem by advancing the technology and using the generator to charge 12-volt batteries that will be up for rent at about $0.20 apiece. "In our system," said Jain, "one toilet will eventually create the revenue to build another one. We have essentially used the batteries as a vehicle to provide more toilets."
All told, powering the batteries is a fairly efficient conversion. In a serious twist on the old joke, one might ask exactly how much waste it takes to light a light bulb. Jain's answer: one human produces enough waste each day to power a 60-watt light bulb for six hours.
The heart of the project though, is improving public health. Poverty has many measures, but not having a pot to -- well, you know the adage -- can have devastating consequences. There are obvious health implications like contaminated food and water, the rapid spread of communicable disease. Katherine Theall, epidemiology professor at Tulane and Jain's adviser, sees reduced risk of diarrheal disease as one of the immediate health effects of better toilet access. Theall also points to factors that are harder to measure -- dignity, self-esteem, and mental health -- as well as increased safety for women.
Women, reluctant to do their business out in the open, typically take long walks to secluded places, and this puts them at daily risk for rape and sexual assault. Girls often drop out of school as they approach adolescence because there are no separate facilities for them; according to UNICEF, 46 percent of schools don't have separate toilets. "There's an entire generation of young women, when they reach puberty, who are forced to drop out," said Jain. "I mean, where are they going to change their pads? It's absurd."
Despite the health and safety benefits of its product, Humanure still might face an uphill climb when it comes to getting people to adopt its new toilets. Ajith Kumar, of the World Bank's Water and Sanitation Program, explained via email that open defecation is less a matter of poverty than one might assume. For a long time, he said, there was no social norm in Indian society against it. In fact, Kumar notes, since the Indian government made sanitation a priority in 1986, a focus on building toilets led to success when, in some areas, it was adapted to include strategies for behavior change. One of the more notable efforts has been the "No Toilet, No Bride" campaign in the northern state of Haryana. (Martha Stewart's not the only one who can set the tone for matrimonial must-haves.)
Humanure won't lean on catchy sloganeering, but its toilets will be built in central locations, and the group hopes sheer proximity to clean toilets will change some people's habits. What's more, the batteries are a clear incentive to encourage toilet use. Renting the batteries is cheaper than purchasing the kerosene currently used to light lamps, and as the batteries get their charge from human waste, there's an obvious economic incentive to use the toilet. After all, Jain said, the more people use the toilets, the more electricity the community has.
Plus, Humanure is considering something akin to a membership model, where the more a household uses the toilets, the greater the discount they receive each month off their battery rental costs.
Of course, there are limits. The batteries can't be used to run large appliances, but such devices are rare in mud-hut villages like Sukhpur, where the first block of pilot toilets is being built. There, a little over one percent of homes are connected to the power grid, so Humanure is also training locals to install wiring into off-grid homes (charging about $1 per home), to make them ready for the batteries.
People will be able to run things like fans, radios and lights. If threat of dysentery can't sufficiently coax people into using the toilets, it seems being able to charge their cell phones -- which are common -- might be enough.