researchers from the california institute of technology have created a prototype for a solar-powered sanitation system that can be used in remote parts of the planet that are not currently served by municipal sewage systems. caltech’s prototype, which won first place in the reinventing the toilet challenge hosted by the bill & melinda gates foundation, uses the sun to power an electrochemical reactor. the reactor breaks down water and human waste into fertilizer and hydrogen which can be stored in hydrogen fuel cells as energy. the treated water can then be reused to flush the toilet or for irrigation. the research team is working on a second-generation prototype with the goal of developing a robust, scaleable system that is ready to use all over the world.