June 3, 2014
Researchers at the University of Colorado Boulder have developed a self-contained solar-powered toilet that protects groundwater quality, prevents the spread of disease and transforms human waste into biochar for soil improvement.
The toilet uses eight parabolic mirrors to concentrate sunlight, heating a quartz-glass rod connected to eight bundles of fiber-optic cables, which then heat the reaction chamber to more than 600°F (315°c), sterilizing the human waste to produce useful biochar.
“Biochar is a valuable material,” said researcher Karl Linden. “It has good water holding capacity and it can be used in agricultural areas to hold in nutrients and bring more stability to the soils. A soil mixture containing 10 percent biochar can hold up to 50 percent more water and increase the availability of plant nutrients. Additionally, the biochar can be burned as charcoal and provides energy comparable to that of commercial charcoal.”
The technology was designed and built with support from the Bill & Melinda Gates Foundation’s “Reinvent the Toilet Challenge,” a competition created to spur solutions to the problems associated with waste pollution.