Video: Computer genius Bill Gates new invention... the water-less loo
THE world's richest man has set himself a new challenge – to improve sanitation for the poor
More than 230 years after a Scottish watchmaker called Alexander Cummings patented the flush toilet, Bill Gates yesterday handed $100,000 to a team from the California Institute of Technology who believe their invention goes one better.
Flush toilets, Gates wrote in a recent blog, "are irrelevant, impractical and impossible for 40pc of the global population, because they often don't have access to water, sewers, electricity and sewage treatment systems".
A toilet in the developing world is often no more than a hole in the ground, otherwise known as a pit latrine. When there is no practical way of emptying it, its users must dig another, or defecate outdoors.
The world's richest man, who is also the planet's most generous philanthropist, has set inventors the challenge of developing a lavatory that will work in the most deprived and impoverished environments. To qualify, the prototypes must operate without running water, electricity or a septic system; must not discharge pollutants; and cost no more than five US cents a day to run. If they also provide a bonus in energy or other resources, even better.
The challenge has ignited a volcano of ingenuity. Caltech's winning entry is based on a solar-powered electrochemical reactor which breaks down faeces and urine into hydrogen – which in turn becomes a back-up source of energy.
Second prize went to Loughborough University's effort, in which the waste is turned into biological charcoal which when burned produces the energy to power the system. It also recovers water and salts from the faeces and urine.
Mr Gates was confronted with the way the other half lives on a visit to Durban in South Africa in 2009 when he learned all about the pit latrine, and its variant the VIP latrine – "Ventilated Improved Pit Latrine" – which has an airpipe to carry away the fumes.