In the serene, agriculturally rich outskirts of rural Kenya, in Kangema constituency, Murang’a county, a lone man is quietly leading a green energy revolution—one bucket of cow dung at a time.
Motivated by the need to reduce the ever-rising energy bills and avoid the harmful health effects of indoor smoke from open fire cooking, Edward Mwangi took the bold step towards energy self-sufficiency two years ago.
He installed a biogas system, which has seen the family not only significantly cut down on energy costs but also embrace a cleaner and more sustainable way of living, as well as conservation of the environment.
“At the time, the price of LPG gas, charcoal and firewood had skyrocketed and as much as I needed to cut costs on that due to hard economic times, I also needed to reduce the respiratory problems caused by smoke emissions from the kitchen,” he says.
“Already I had four dairy cows and therefore knew I had a reliable source of energy to fuel the biogas system,” he noted.
Armed with determination and resilience, Mwangi installed the 12-cubic-meter biogas digester for sh150,000, which to him was a significant investment yet a worthwhile venture.
Using a fixed-dome digester, a simple yet efficient design that requires minimal maintenance, he feeds the system daily with a mixture of cow dung and water.
“For every three buckets of cow dung, I mix in four buckets of water daily and this is more than enough to cook for my family and even heat water,” |he says.
Using the simple underground digester, the cow waste ferments to produce methane gas which is an efficient, smoke-free and eco-friendly source of fuel.
Though the setup cost is high—a major barrier for many rural families, he says the long-term benefits far outweigh the initial expense.
The benefits of the system extend beyond cooking fuel as he no longer needs to purchase LPG gas, kerosene, or charcoal.
Beyond cost saving and health benefits, the system produces nutrient-rich slurry as a by-product, which he uses as fertilizer on his farm to boost his vegetable farm yields.
Moreover, Mwangi rears chicken and occasionally mixes the slurry with poultry feed thus cutting down the cost of animal feed.
“We mix bio-slurry with poultry feed at a ratio of 4:1. Consequently, the chickens gain weight faster and produce more eggs,” he says.
Notably, the lush green healthy fodder thriving in his 3-acre piece of land stands as a clear testament to the nutrient-rich slurry produced by the biodigester.
Having the soil enriched naturally, the crops and fodder grow faster and healthier, leading to increased farm productivity.
“Biogas has helped me earn indirectly from providing a cleaner kitchen environment and, reducing deforestation to getting better yields from my crops and animals,” states Mwangi.
He also offers training and support to other farmers who are interested in adopting the biogas technology to replace charcoal and firewood in their homes.
His wife Gladys Wanja, beaming with a smile as she demonstrates her culinary skills using the smokeless gas concurs that the transformation in her daily cooking routine has been profound since the installation of the biogas.
“The gas we produce cooks everything from tea to foods like Githeri, and even warms our bathing water. Firewood collection, once a laborious and time-consuming task, is now a thing of the past,” she explains.
“There’s no smoke and soot emissions and I no longer suffer from respiratory problems which were common when I was using firewood,” she says adding that, “It ignites quickly and cooks faster, saving me time and effort in the kitchen,”.
Before installing the biogas system, the family was spending approximately Sh3,500 per month on LPG gas, Sh1,800 on firewood, and Sh1,200 on electricity bills, but now spends only Sh 500 on electricity.
Beyond convenience and cost-saving, the family has also seen a noticeable improvement in indoor air quality, a health benefit that cannot be overstated.
Mwangi intends to expand the use of biogas to raise more chickens, light the house, and even power his chaff cutter.
He urges more households to embrace this clean and efficient energy solution to light up rural kitchens so as to reduce deforestation, lower greenhouse gas emissions, manage waste efficiently and improve soil fertility through the bio-slurry, the by-product of the biogas process.
By Florence Kinyua and Lesley Linus
