Pruned branches of green tea give off green energy
A tea farm in Nandi county. Gasification could also decarbonise some of the heat used in tea processing.
Global supply and demand determine tea prices. And now, climate and land use changes adversely impact production. Tea being perishable, factories require uninterrupted power at a competitive cost.
Kenya’s vision for green industrialisation and growth, powered by African resources, could future-proof the sector. President William Ruto reinforced this at February’s EU-Kenya Business Forum.
The potential for biomass power in the country is at least 500 MW per hour, against installed capacity of 2MW, Rural Electrification and Renewable Energy Corporation (REREC) data show. But excess high-carbon biomass such as tea prunings does not just generate power. Gasification could also decarbonise some of the heat used in tea processing.
Since 2007, Paul Willacy, managing director of UK-based Compact Syngas Solutions (CSS), has focused on gasification, maximising production from biomass into syngas that is converted to heat and power. He says “a gasification process can run 24 hours a day”, which matches tea factories’ peak demand.
Our consortium of CSS, the International Institute of Tropical Agriculture and The Grass Company is qualifying biomass for the Kenyan tea sector. We are building on past lessons by ensuring electricity supply matches demand, affordable suitable biomass is available all year round and concerted skills development builds a pipeline of talent. Our partners include key Kenyan universities.
A small—but vital—amount of the prunings is converted to biochar, which will be returned to the field in line with Kenya’s move to a circular economy and re-building soils. Biochar retains water, improves fertiliser efficiency and sequesters carbon.
Our feasibility study, producing and applying biochar on farms and returning unused shavings, has convinced farmers that a layer of prunings may be removed. We are also engaging the Tea Board of Kenya to showcase that “not all carbon is the same”.
To facilitate the tea sector’s—and captive power producers’—uptake of gasification, innovative policies like removing taxes on women gasification engineers, technicians and operators, are vital. Making waste management (‘biomass supply chain’) a public service or public-private partnership will incentivise gasification and the circular economy.
Kenya Bureau of Standards could adopt international or European standards for industrial production of biochar. The Kenya-UK Economic Partnership Agreement (EPA) rendezvous clause has left “environmental and sustainable development” open for negotiation.
Since half the tea drunk in the UK originates from Kenya, including gasification and “green” tea could enable access to affordable reliable green energy, less pollution, reversal of environmental degradation, replenished natural resources and improved working conditions.
More uses for high-quality syngas into green hydrogen will offer longer-term transportation and fertiliser production opportunities and the tea sector might be ahead of regulatory constraints (like obligation to reduce Scope 3 emissions) and consumer expectations. Starting with the tea pruning.
- Ms Aarti is the green tea business, policy and Kenya lead at International Institute of Tropical Agriculture. [email protected]. @AartiShahAfrica
