Generating power from human waste
May 24, 2013
Many people complain about the high cost of living and utilitie bills. The expense in paying for electricity and supplementing it with charcoal, which is not only expensive but leads to the degradation of environment, has left an adverse effect on our savings and environment.
By Norman Katende
Many people complain about the high cost of living and utilitie bills. The expense in paying for electricity and supplementing it with charcoal, which is not only expensive but leads to the degradation of environment, has left an adverse effect on our savings and environment.
But many do not realise that they can cut expenses by using their waste to generate energy.
Turning human waste into energy
Human waste can be turned into biogas that can be used for cooking and lighting and also for running generators to provide power for electronic appliances.
Wangwe Mulakha, who has been using biogas from human waste for lighting his house and cooking, says: “It is like any other gas. I have a capacity of 3,000cc, which is enough for cooking and lighting the house.”
Mulakha is one of the about 100 families in Manafwa that have benefited from the Heifer International and SNV project.
“The manure that comes from the bio digester is good. I used it when I planted bananas and coffee, and two months down the road, I can see a big difference,” adds Wangwe.
He, however, says his only problem is the constant feeding of the bio digester.
“We have to put in about two basins daily. When we over feed it, the bacteria become lazy and do not produce the required gas,” he adds.
Focus turns to schools
Michael Ahimbisibwe, a senior energy officer from the energy ministry, says they are now turning the focus to schools.
“Schools have a bigger source of human waste and if they embark on this project, they will save forests, which will lead to better climate and environment,” he says of the project that is under the alternative energy sources.
This, coupled with waste from farm animals, can help in feeding the bio digester. The waste from the digester can then be used as manure for crops.
“We have already identified two schools where we will set up pilot projects,” Ahimbisibwe adds.
He, however, notes that change of attitude is the biggest problem threatening the project.
“People are not comfortable with using human waste to cook food.”
The bio digester is a tank which is oxygen free and helps in the treatment of human waste. It creates methane gas, which is used for lighting and cooking.
“We do not want to give people technology that they will not embrace. It is the cheapest way of creating energy as long as you have enough waste,” says Ahimbisibwe.
Cost of setting up the project
Setting up the project could cost about sh4m to sh10m, depending on the size.
“This might seem expensive but you are already saving a lot by not building a latrine or emptying the septic tank.
The digester receives the human waste and turns it into manure. You also get rid of the smell that comes from the human waste as it is this that is used for producing methane.”
Godfrey Ndawula, the commissioner for alternative energy, says the bio digesters can also take animal waste because it possesses bacteria that produce methane.
According to Ndawula, the Uganda National Domestic Biogas Programme, which has been handled together with the Heifer Project with support from Netherlands, has already reached a numbers of households.
Best option
“If you consider the fact that this facility will last over five years and produce manure for farmland, you have to embrace it,” he says.
An average home needs about 30kg of waste to produce enough gas for cooking per day.
“With the increasing population, we have no alternative but to use biogas toilets,” notes Ndawula.
He observes that the initial cost of the technology, lack of access to technical personnel and lack of awareness have all played role in making the project difficult to implement.
“But we have come up with standards to ensure that we have quality assurance in the construction of the bio digesters to give people more confidence. Our next step is to set up biogas companies where we can get technical equipment,” he says.
Adapted from Business Vision