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Biogas Production Relieves Farmer In Kirinyaga County


For Joseph Ngari and his neighbour Mary Wambui, life has never been the same since they discovered bio-gas technology last year.

“I have seen great change within my family since I started generating bio-gas, my wife and four children can also testify to this. My wife no longer uses firewood to cook, and this saves us a lot of time and money. We don’t have to cut trees or use charcoal anymore,” says Ngari from his home in Karia village, Kirinyaga County.

According to experts, it costs about Sh70, 000 to install a basic biogas unit, but to Wambui and Ngari the benefits that come after, is what they term as the great transformation of their life.

Wambui, has a success story to tell. She is a dairy farmer who also practices mixed farming.

 “I was a teacher by profession and what I earned then cannot be compared to what I get now. With dairy farming, I can generate biogas, sell milk and supplement my income,” Wambui said.

“The biggest gain in this biogas production is that I do not have to cut down trees for firewood. These days we are really hit by the climatic change phenomena but with biogas, we get green energy and emit very little carbon dioxide into the atmosphere,” she notes.

She says since she embraced the technology it has transformed her life completely at her two-acre farm where she specializes in bananas, arrow roots, macadamia, coffee, tea and livestock farming.

Looking back, Wambui says she is proud and happy that she took the step of faith and has no regrets in venturing into mixed farming.

She attributes her great success to dairy farming which has brought many benefits apart from milk production. “Dairy farming has proved to be very reliable for me since I started my farming after I inherited a farm from my late father. I enjoy so many benefits and above all, this biogas,” she says.

Her biogas unit was installed with the support of Norwegian Church Aid, a Non- Government Organization, who donated Sh60, 000 and she paid the balance of Sh 40, 000. “I am glad that I was able to get their support which has made me a proud farmer who uses bio-gas for her cooking needs.

Figure 2: Wambui uses bio-gas for her cooking needs.

 “Biogas generation is not expensive after the initial installation cost,” Wambui said in a recent interview.

She said she uses cow dung from her animals and the same waste is directed through small trenches to her farm to be used as organic manure.

By so doing, she avoids the cost and environmental effects related to fertilizers. The simple technology of connecting a tank, commonly known as, a digester, and channeling it to a central point where gases are produced, has seen many farmers like Wambui and Ngari transform their lives in a big way.

For Wambui, the main raw material for the biogas production is the waste from her three heifer breed cows.

She gets about 30 litres of milk every day. “These cows generate a lot of dung during feeding and this is fed into the digester which in turn produces mixed gases as a result of breaking down the organic matter, in the absence of oxygen,” she explains.

Figure 3: The biodigester at Wambui’s farm

The primary gas produced is Methane plus other gases like Carbon dioxide and Hydrogen in small quantities.

It is here that energy is produced in form of cooking gas and directed to the kitchen through special pipes where it is used for heating purposes like cooking.

Biogas can also be compressed, the same way natural gas is compressed in advanced countries, and could be used to power motor vehicles.

In the hilly villages of Kirinyaga County, many farmers have planted trees and the introduction of biogas technology will go a long way towards sparing the trees from loggers for sale as wood fuel.

So far, this has had a big impact on the protection of the environment and led to a predictable weather pattern.




  1. Kibiriti
    January 20, 2021 at 9:49 am

    Will try this out in my farm.

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