A video of a farm powered by biogas from chicken manure has caught the attention of many social media users, particularly on LinkedIn. In a country struggling with energy, why is chicken manure not a simple solution.
According to Wally Weber, Chief Executive Officer (CEO and owner of Black dot Energy), chicken manure is a challenging substrate in South Africa.
“The only way to use chicken manure for biogas production is if it is clean chicken manure. The way to achieve such, is to grow layers on metal cages where chicken waste falls clean, through cages onto a conveyer belt, to a collection point.”
In SA, the practice of keeping chickens in cages on wireflooring is considered inhumane.
It is common practice for chickens to be able to at least, partly roam freely, even if it’s in an enclosed tunnel with woodshavings. They should be limited to at least 3 or 4 chickens per square meter.
“When woodshavings are used, the substrate becomes unusable for biogas. The liganen in the wood of woodshavings, stops it from being broken down in a biogas digester in an anaerobic process.”
“One way that is viable is using abbatoir waste, because it is clean, and organically uncontaminated, although it does have some pathogens.”
A study conducted for the Botswana meat commission via UNIDA by Webber proved abbatoir waste for biogas production is both technically and financially viable.
Biogas is renewable fuel that’s produced when food or animal waste is broken down by microorganisms, in the absence of oxygen. Such a process is called anaerobic digestion.
South Africa has an estimated 300 bio-digesters of which only 50 are registered commercial biogas plants, larger than 100kW. Biogas has the potential to displace an estimated 2,500MW of grid electricity.