"Waterless sanitation systems can also be a source of renewable energy. Loowatt are a small UK-based company working to develop a clean, safe waterless toilet, and a system for turning waste into energy and fertiliser. With funding from the Bill and Melinda Gates Foundation, they tested their system in Madagascar.
Local people pay a small fee to use the Loowatt toilets in Antananarivo. The waste from the toilets is processed in a bio-digester, which produces methane gas and fertiliser. The methane can be burnt for cooking, or to produce electricity. People who use the Loowatt toilet in Madagascar can also charge their phones using electricity that comes from the waste."