"The pair are now working with the global Solar CITIES program, based in Chester County, which trains trainers to introduce this simple biogas technology into resource-poor communities and other places lacking sufficient public health infrastructure—including refugee camps.
Thomas Culhane, a research scientist in urban planning, environmental analysis and policy, is a co-founder of the organization. He believes biodigester systems, whose simple technology requires little more than plastic cubes and tubes, can turn dangerous waste into an asset. He says a biodigester converts waste into soil in three to six days—instead of three to six months of composting. The clean gas that is produced requires no additional refining to be usable, and it also creates nutrient-dense fertilizer in just 24 hours. Using up the food waste helps reduce the greenhouse gases that would be produced if it rotted in a landfill. The process extracts the last bit of photosynthetic energy from the food waste and converts it to cooking fuel. A next generation design uses mirrors to direct solar energy to the units to keep them warm in winter.
As Solar CITIES vice president and co-founder Janice Kelsey puts it, “We’re able to deal with food and manure at its source.” Biodigester technology on an industrial scale is already in use in countries such as Germany and Sweden. Culhane and Kelsey’s efforts center on the construction of“appliance-sized” digesters for home use."