Incinerating toilets may be powered by electric, gas, dried feces or other energy sources. They are used in environments where human waste cannot be otherwise dumped, or where normal toilets are too expensive or cumbersome to install. Such toilets gather excrement in a holding tank and then incinerate it, reducing it to pathogen-free ash. Some will also incinerate grey and black water created from showers and sinks.
In 2011 the Bill & Melinda Gates Foundation launched the Reinvent the Toilet Challenge to promote safer, more effective ways to treat human excreta. Some research teams have received funding to work on developing toilets based entirely, or in-part, upon solid waste combustion. For example, a toilet under development by RTI International is based on electrochemical disinfection and solid waste combustion.This system converts feces into burnable pieces and then usesthermoelectricdevices to convert the thermal energy into electrical energy while excess heat dries the newer feces as it enters the system.