Waste tea clippings are generating greener energy for factories in Kenya.
Kenya produces £1 billion of tea a year, with up to a quarter of it destined for British tea bags.
But the industry is threatened by an unreliable and expensive electricity grid that cuts out for an hour a day on average, causing producers to rely on diesel generators for power and wood for heat.
Waste-to-energy company Compact Syngas Solutions (CSS) are helping safeguard the beloved British cuppa with their advanced gasification process that uses waste products to generate a syngas – a mix of hydrogen, methane and carbon dioxide and monoxide.
The syngas can be burned as a greener fuel, saving up to 2.8kg of carbon dioxide per litre of diesel, and up to 1.98 tonnes of carbon dioxide per tonne of fuelwood.
Syngas and hydrogen gas can be generated from waste products, including biomass like waste wood and other selected non-recyclable materials.
Carbonised biomass – biochar – produced in the process can be applied to farmland to improve soil fertility and remove carbon dioxide from the atmosphere as part of a capture and storage scheme, reducing the climate footprint of tea or generating income from emissions trading.
Partners from the International Institute of Tropical Agriculture have quantified the removable stocks of tea pruning, identified supply chain operations and delivered costs to the factory, and built a model for assessing savings in energy bills and fuelwood demand.
In a proof-of-concept field trial they found that recycling of biochar to plantations can boost tea yields by up to 23%, increasing fertiliser use efficiency and drought resilience.
Each 500kWh plant will create jobs for up to ten skilled technical and operational workers with an extra ten workers in fabrication and support. Some 300 jobs should be created in Kenya within the first five years.
Once the project has proved its success in Kenya, it will expand to Malawi, Uganda and South Africa, before spreading across the world.
The company, based in Deeside, Wales, recently secured almost £4 million in government funding to make its biomass and waste-to-hydrogen plants even greener by using carbon capture.
CSS managing director Paul Willacy said: “Every year Brits drink millions of cuppas from Kenya, but the tea industry there is at risk from an unreliable and expensive power supply.
“We’re going to provide energy security to the factories that process our tea, while reducing emissions, improving crop yields and bringing jobs to the country.
“We’re hugely excited about the impact this could have on the tea industry in Kenya and worldwide.”
Dr Dries Roobroeck, technical lead at the International Institute of Tropical Agriculture, said: “We’re always looking for innovative ways to improve crop yields, protect farmer livelihoods, and create sustainable farming systems, and this project ticks all these boxes.
“Gasification will also allow tea factories to reduce their carbon footprint and help global tea brands decrease their Scope 3 emissions. More reliable electricity will improve the quality of the final product – so the benefits will be felt all the way across to the consumer.”
High enery costs and poor grid stability threaten the viability of Kenya’s £1 billion tea sector, which produces 70% of Africa’s black tea.
CSS’s innovative project will be the first time that waste prunings from tea production are used to produce clean electricity and heat, reducing costs and carbon emissions.
Biochar left over from the process is used to rejuvenate the soil – increasing tea yield by up to 23% – or to store carbon underground to mitigate climate impacts.
The project is also creating jobs for Kenya’s well-educated underemployed young people and boosting prospects for women.
