Biogas Digesters Promote Clean Energy

April 8, 2015

In the dimly lit hut, Sibusisiwe Madyango, 62, turns on a switch on the cooking stove, lights up a match and suddenly a fray of flames jumps upwards. A smile lights up on Madyango’s face as she explains how the biogas digester has changed her life.

Since January 2015, Madyango has been participating in the Zimbabwe Domestic Biogas Programme aimed at increasing access to clean, reliable and affordable supply of energy at household level.

“The biogas digester has been a great development for our household. I now save on labour and time. I don’t have to spend time looking for firewood anymore,” she said.

The landscape surrounding her homestead in Nharira communal area – approximately 200 kilometres southwest of Harare, Zimbabwe’s capital – now looks like a desert with only a few trees remaining.

Many of the trees in this remote community have been cut down to fulfil household energy needs. In fact, it is now regarded a crime in the area to cut down a tree, a measure to try and save the remaining trees.

Madyango said the biogas digester has helped her to significantly reduce her usage of firewood for cooking.

“Some of the tufts of grass that I use as fuel are toxic and leave the inside of my hut rather smelly, but cooking using gas from the digester has made my life easy. When I want to have a hot bath, I merely flick a switch and a match rather than have to look for firewood,” she said.

She added that other women in the area were interested in installing biogas digesters at their own households after witnessing its efficiency. On average, it costs 1,500 US dollars to construct a biogas digester.

A biogas digester produces biogas through the natural anaerobic decomposition of organic material. So Madyango and the six members of her household feed the digester’s fermentation pit with cow dung and water.

The resulting gas is fed directly to her hut to provide energy for cooking. The biogas digester has already started producing organic waste which will be dried and used as fertiliser.

Although Madyango has a herd of 33 cattle which produce a surplus amount of cow dung, experts say only five cattle per household are needed to produce enough cow dung to feed the digester.

The Hivos Southern Africa hub is currently partnering with SNV, the Ministry of Energy and Power Development, Ministry of Agriculture, Mechanisation and Irrigation Development to implement the project aimed at increasing the uptake of biogas technology in Zimbabwe.

The five-year Zimbabwe Domestic Biogas Programme aims to establish a vibrant biogas sector that will benefit more than 67,000 households. The project follows a market-driven approach in promoting the dissemination of biogas technology.

The project is being implemented within the scope of the UN’s Sustainable Energy for All (SE4ALL) initiative that seeks to ensure universal access to modern energy services, enhance energy efficiency and increase uptake of renewable energy.