Kenya: Biogas International pioneers biowaste solution

Killing two birds with one stone, a Kenyan energy technology company has developed a ‘digester’ that can convert polluting water hyacinths into biogas.

Biogas International has developed a carbon-efficient alternative to conventional charcoal cookers.

Partnered with Swedish drug manufacturer Astra Zeneca and the Institute for Sustainability Leadership at the University of Cambridge, the Kenyan energy technology company produced a so-called ‘Flexi Biogas’ device for household use.

Named a ‘digester’ for its capability for breaking down plant waste into biogas, the product has so far been tested by 50 families living in the West Kenyan city of Kisumu.

Tony Otieno, a member of one of said families, praised the clean energy output of the device.

"The gas has no smoke, does not smell, and it is much faster than the jiko [note: a charcoal stove]."

So far, the project’s small-scale implementation has not only served to eliminate the use of charcoal and wood in the testing households, thereby engendering a zero-carbon emissions approach in household waste management, but also provided families with the added benefit of enjoying the fruits of their labour sooner, considering that gas allows for faster cooking.

The digesters were sponsored by Biogas International with many respondents receiving them free of charge. This is noteworthy, considering that at a price point of $650, a digester is not commonly affordable to Kisumu natives. In Kenya, the GDP per person value was estimated to be just over $1,800 per person in 2020 by the World Bank.

As such, the financial viability of ‘Flexi Biogas’ devices is still up in the air. Though upscaling in the sense of large-scale commercial applications is possible, the profit margin over the next five years is set to be low as individual production costs run high. To turn over a higher profit margin, Biogas International requires further investment into its proprietary technology.  

The digester’s ecological potential may be set to clear that barrier, however.

Said device uses water hyacinth waste as a source for its clean cooking fuel.

Water hyacinths are an invasive marine plant species that grows freely across the world. Ranging from 0,5-1m in height, the plant is responsible for impeding water flow, paralyzing navigation as well as damaging hydroelectricity and irrigation facilities. These ‘weeds’ negatively impact water quality, a proliferation of the plants also being considered a breeding ground for bacteria and mosquito larvae, the latter of which are known for being disease carriers.

In Kenya, water hyacinths are predominantly found across large swathes of Lake Victoria, a freshwater lake situated between Kenya, Uganda and Tanzania.

A ‘Flexi Biogas’ device uses 2-3 kg worth of the invasive marine species, harvested directly from said lake.

According to Dominic Wanjihia Kahumbu, head of Biogas International, the marine plant is ‘a blessing in disguise’.

Currently, two more digesters are being developed. These are intended for commercial application in restaurants, chicken farms and fish drying facilities within the area.

The company has posted a video of a large-scale application of its product at Ngong Market on its Facebook page.