A team of scientists in Minoa, New York have created the first prototype for a small-scale co-digester reactor using human and food waste to generate electricity for their village.

    Although the technology is not new – most small-scale digesters currently used are found on farms – it is the first time it will be employed in an urban environment in the U.S. Once it’s up and running, the team wants to create enough electricity to power a small store or apartment building in the 3,400-person village. They also plan to reduce the $70 per ton cost of trucking sewage out of Minoa, since what comes out of the co-digester is a pathogen-free compostable material that they will reuse.

    Plans are in place to collect an estimated 15,000 pounds of food waste daily from the local school district and mix it with human waste, cooking it to generate methane gas for producing electricity. The co-digester is heated in a unique way – using a set of coils buried inside a compost heap, different again from digesters that use a boiler system for heating. Once the project takes off, the village hopes to adopt a curbside food waste collection program to supply more reactors.

    Dave Johnson, professor at the State University of New York College of Environmental Science and Forestry, who is working on the project, said the aim is to create a fully functioning system that integrates several self-sustaining technologies. Not only is Minoa creating a co-digester, they have also constructed a wetland wastewater treatment system that successfully eliminated pharmaceuticals estranol – a common ingredient in birth control – and ibuprofen from runoff. They also have a greenhouse for growing algae for phosphorus uptake. The system will serve as a module for urban agriculture, a practice that is not very common in the U.S., he said.

    To keep costs down, the co-digester will be constructed out of existing or recycled materials in a “do it yourself” fashion – the main reactor is made from a plastic highway culvert and PEX tubing, or plumbing pipe. Household insulation contains the heat produced.

    So far, the test co-digester only has a volume of about 300 litres, which generates about half a cubic meter of methane gas each day, or about enough to power a lawnmower, Johnson said.

    The idea behind creating the co-digester was to not just to save the environment but also to save livelihoods – small villages and towns are being hit with budget cuts.

    “What we decided to do, instead of having these entities fire people, lay off people, reduce services, what we decided to do is offset the costs of operations,” said Steve Giarrusso, research biologist and chief operator of the Minoa wastewater treatment facility. Cutting the sewage elimination costs while powering the village with its own sustainable electricity source that might just allow them to get off the grid completely.