Ask the average person to name a type of renewable energy. I would assume whatever they say is one of the types of renewable energy that you would see here in the United States. The answer is probably an energy source like wind power, hydropower or solar power. What you are unlikely to here is poo poo power. Though in the central and east African state of Rwanda, that is certainly not the case. In Rwanda, the preferred alternative energy source above all is biogas. Usually biogas means dead plant and animal material, animal waste, and kitchen waste turned into fuel. It is not common in the United States, but it has been utilized here, for example, by farmers in Texas and Vermont with cow dung. Rwanda does that too, but they’ve taken this crappy idea a step further.
In Rwanda, the prisons have huge populations. For example, in Nsinda Prison, there is around 8,000 inmates. Most of them convicted for involvement in the 1994 genocide in Rwanda. The sewage created in prisons like Nsinda was turning into a serious health hazard for the those in and around the prison. Another problem facing Rwanda in and out of the prisons was the demand for firewood for cooking that was locally harvested in Rwanda’s rainforests. That method of cooking brought its own health hazards from the smog it created when done indoors. A sustainable solution to this was found in the form of biogas. In this case, they recycle the inmates’ own waste as a way to generate energy.
In 2001, biogas plants first appeared in prisons. The idea was a complete success, and it has since expanded to all 14 prisons in Rwanda. An example of the success can be seen at the Nsinda prison which has achieved an 85 percent reduction in energy costs since switching to biogas. At Nsinda, biogas also accounts for 75 percent of all energy used.
The biogas is made in the prisons by mixing the waste of the inmates with cow dung and water outside the prison walls. The combination of waste is filtered before entering large digesters that create and store the gas. This biogas is then used to in the kitchen to cook the food for the inmates.
Now, the Rwandan Government promotes biogas to the public as an alternative means to fuel cooking and lightning, rather than the harmful biomass that is usually used. It can now be found in homes and is common in schools too. A program was launched in Rwanda in 2009 to promote biogas in places without access to electricity. The Government of Rwanda now encourages all Rwandans with two or more cows to have its own biogas plant.
So could something like this work in the United States? Countries much larger than Rwanda have taken to the idea. In both India and China, sewage has been used as means of energy. In the case of China, it is said that Marco Polo observed the Chinese using covered sewage tanks to generate their energy way back in the 13th century! Reporters in the United Kingdom have even contemplated such an idea as a replacement to North Sea gas in the future. While I think it could, its not something I would want to think about!
For more, check out this video on youtube on the Rwandan prison biogas.