Good Energy’s Clean Energy Specialist Rory Fox-Evans took on an unusual activity in lockdown – inventing a new biodigester to help Tanzanian communities, and in doing so protect elephant populations. For International Day for Biological Diversity, he tell us his story.
Like many people in early 2020, I could never have predicted how the year would turn out – but it provided some unexpected opportunities I couldn’t turn down. I have met and worked with some interesting people, to change the lives of both humans and animals – hopefully for the better!
Who are Wild Survivors and what’s the problem?
In September 2020, I met Fran – founder and director of Wild Survivors – a charity dedicated to maintaining coexistence between humans and elephants in Tanzania. She explained that the population of elephants in Tanzania had been severely impacted by poaching and reduced tourism due to the pandemic. Therefore, she founded Wild Survivors, with an aim to stabilise and increase the elephant population. One of the main ways they do this is through the protection of the elephant’s “migration corridors” (stretches of wild habitat that the elephants use to move from one region to another), which have become increasingly fragmented by urban and agricultural development. The loss of habitat threatens elephant survival and increases the chances of contact with poachers. Wild Survivors’ primary solution to protecting habitat is through the use of beehive fences installed along boundaries to prevent elephant crop-raiding and persuade the herbivores to continue onwards to their migratory corridor.
Often, Acacia trees are pruned or cut, and being a prime food source for the elephants, this forces elephants further afield to find a good meal – which risks them running into poachers and increased conflict with people in the process.
Although the beehive fences were effective in preventing crop-raids by elephants and subsequent retaliation, the corridor habitat needed greater protection. Two villages border one of the last remaining elephant corridors in Northern Tanzania. These communities depend on resources from the corridor, such as firewood for cooking and heating homes. Often, Acacia trees are pruned or cut, and being a prime food source for the elephants, this forces elephants further afield to find a good meal – which risks them running into poachers and increased conflict with people in the process.
The solution: designing a biogenerator
Fran had the idea of using the village’s waste as fuel, rather than using the trees, with an aim to using biogeneration as a means of making gas for cooking. Wild Survivors didn’t have a huge budget for purchasing pre-built generators, which were also pretty large and hard to get out to the remote areas that they were needed. As a result, I decided to offer my help in designing a small-scale biogenerator that would be cheaper and easier to transport to the villages.
Despite my background in microbiology, designing a biogenerator that would work on such a small scale was no easy feat! It took a lot of tweaking to work out how much space we would need, how we would keep the bacteria warm enough to produce the gas, and what we would use for the fuel. Eventually, I came up with a design that we could produce from easy-to-find components that would use a mixture of cow manure and the village’s food waste as fuel. Each unit would produce enough methane per day to cook for a family of four, and leave a slurry that could be used as fertiliser to increase the village’s crop yields. Win-win!
Currently, the biogenerator is being tested by Gervas to assess which fuel mix will give the best yield of methane. Once this is complete, Wild Survivors will be in a position to roll out the generator to villages across the region, hopefully reducing the number of human-elephant conflicts and preventing deforestation in the process!
Good Energy has made a donation to Wild Survivors to support the great work they do. If you wish to do the same, you can do so here.