
The full team behind the human waster bioreactor with Leroy Mwasaru second from right. The team started off with five members, but then two graduated to university.

The plan —
Leroy Mwasaru and his team came up with this blue print to explain the key steps in the system. Mwasaru calculated that in one term the school used 196 tonnes to create enough energy to cook for all the students. He then deduced that if each of the 1,300 students produced 200g of human waste per day, his bioreactor system could save the school $42,800 per year as they would not have to buy as much cooking gas.

The team —
The team collect cow dung from the school farm and food refuse after meals and put the mixture along with water in the digester which then produces the biogas. A pipe later carries the gas through to the kitchen and the gas-powered stove.

Natural resources —
Mwasaru calculated that, per term, his school used 28 trucks of wood, or 196 tonnes to create enough energy to cook for all the students. This demand for timber caused problems with the local community who collected firewood from the same forest.

Innovate Kenya founders Francis Meyo (right) and Jacob Lennheden (left) were impressed with the Maseno School students' idea, which was among the finalists in the 2013 competition.

Schoolboy success —
The teenage team behind the Human Waste Bioreactor attend the Maseno school 25km from Kisumu in western Kenya. Founded in 1906, Maseno School is the oldest school in the country.

Pee power —
Similar initiatives are taking place in other parts of the continent. In Nigeria, these teenagers have created a urine powered generator which provides six hours of electricity.

Prison power —
The biogas system at Nsinda prison in Rwanda began operating in July 2010. A system similar to the one designed by Mwasaru, provides some of the cooking energy needed for the prison's 12,000 inmates.