When one thinks of animal dung, one usually thinks: messy. Dutch research institute TNO has developed a prototype of a socket that turns biogas heat into electricity. Together with SNV and BoP Innovation Center, students at Delft University of Technology visited Rwanda for TNO to test this new prototype in people's homes. Who could have ever imagined, that one day mobile phones would be charged with cow dung?
Students Anne Jansen (24) and Diana Alacron (32) spent six weeks in Rwanda's countryside, where they spoke with families to understand their specific needs when it comes to gas and electricity.
"We noticed a need for gas for cooking, but also for electricity," says Diana. "Eighty percent of the Rwandan population has no access to electricity." Meanwhile, according to their research, almost everyone owns a mobile phone - both parents and their children.
"When people don't have electricity, they walk every three days to the city where they leave the phones on little charging stations," explains Anne. "This means a lot of effort, time and money is spent on charging. Electricity would make them more independent".
The biogas socket is still in development, but after their research in Africa, the students are confident with its development. "It's easy to apply," says Diana. "The idea is to simply connect the socket to the cook stove, which means no new difficult system regarding the installation."
How many cows?
Although biogas installations require refined technology, the underlying process is quite simple. One gathers dung and urine in an underground tank and a gas is produced. The resulting residue can be used as fertiliser for agriculture.
So how many cows do you need to charge a phone while still having enough for cooking and light? According to Anne, one needs 400 liters of gas for one hour of cooking. The biogas socket will use 50 to 150 liters of biogas per hour. In terms of dung this means a "daily minimum of thirty to forty kilograms of cow dung, so one needs at least two cows," says Anne.
Both students were surprised to discover it was very impolite to ask how many cows a family owned. "It's like asking in Western countries how much people earn. But it's nice to experience these cultural differences," says Anne. "You may prepare a lot beforehand, but you will always come across something unexpected. Our solution was to simply count the cows in the garden".