Africa’s first biogas-powered electricity producer to sell surplus electricity to a national grid has come online at a Kenyan commercial farm.
The Gorge Farm Energy Park, located in the market town of Naivasha, produces 2MW of electricity and heat to cultivate 1,740 acres of vegetables and flowers, with enough surplus power to feed 5,000-6,000 rural homes.
The farm, roughly 76km away from the capital Nairobi, is owned by the Vegpro Group, an East African vegetable and rose exporter.
Biojoule Kenya, which operates the Gorge Farm plant, signed the agreement to sell surplus electricity to Kenya Power and Lighting Co. (KPLC) for $0.1/kWh in 2016.
The biogas-based electricity is significantly cheaper than diesel-generated power, which costs $0.38/kWh to produce.
Engines for the Gorge Farm plant were supplied jointly by Tropical Power, a Kenyan solar and biogas developer, and Clarke Energy, a UK-based engine service provider.
"The Gorge Farm plant is physical proof that locally produced feedstock can be used to generate clean and cost-effective power for all Kenyans," said Mike Nolan, COO at Tropical Power.
The plant uses anaerobic digestion (AD) to produce biogas, which is then burned in two cogeneration engines to produce the electricity and heat.
Producing the same amount of energy using diesel would require 5 million litres of fuel annually, Nolan said, plus the extra fuel required to transport the diesel inland from the port of Mombasa.
According to Tropical Power, the new biogas plant reduces annual CO2 emissions by nearly 7,300 tonnes, as the farm is not dependent on the oil-based power in the national grid.
Cogeneration is at the moment a tiny market in Kenya, with Kenya Electricity Generating Co. data from 2015 showing that it contributed only 0.7% of the total amount on renewable energy in the country.
Still, some experts forecast significant growth potential for biogas in the Kenyan renewable energy industry, where 49% of power is currently provided by geothermal installations.
"The potential for biogas generated electricity in Kenya is significant," said Helen Osiolo, a policy analyst at the Kenya Institute of Public Policy Research and Analysis.
Osiolo thinks biogas could provide power anywhere in the area between 29 and 131MW, but its development is hindered by a government that is unwilling to pay for it.
"There are concerns that the tariff is too low to attract substantive investor interest," Osiolo said.
Agricultural and municipal waste, which fuel the AD process at Gorge Farm, are also in high demand to be used as fertiliser, further undermining biogas’ possibilities.
Osioli also said biogas in Africa is held back by the belief that it requires large amounts of feedstock to produce any mentionable amount of energy.
Nolan, however, counters this claim by saying that even just 1% of organic material or crops in Kenya would be sufficient to produce 1,800MW of electricity, which is as much as the country’s entire current electrical capacity.
He also states that the AD process produces digestate as a by-product, which can then be used as a natural fertiliser.
According to Tropical Power data, the 49,900 tonnes of farm residues Gorge Farm is able to process annually could produce up to 36,300 tonnes of digestate that can then replace synthetic fertilisers.