Presented by Dr Mary Njenga, Research Scientist at World Agroforestry (ICRAF), during GIZ's session, "Biochar and Its Practical Application to Restore Degraded Lands", at GLF Africa 2021.

1. Bioenergy-biochar systems in small-scale
farms in Kenya
Njenga M*, Gitau JK, Sundberg C, Mahmoud Y, Mendum R
*m.njenga@cgiar.or
g
Biochar for climate-change mitigation and restoration of degraded lands: GLF
Africa 2021 Restoring Africa’s drylands: Accelerating action on the ground

2. Charcoal and firewood (woodfuel) situation in Kenya
Kenya Urban Rural Production /Deficit
Households (HH)
using charcoal (%)
46 42 Growth: 56% 2002-
2013
Over 80% of wood is
from natural
woodlands in
private/individual,
communal land
mainly in drylands
Deficit 55%
Charcoal
consumption per
HH per year (kg)
364 411
HH using
firewood (%)
24 86 Deficit 27%
ACCK & MoE, 2019
Firewood
consumption per
HH per year (kg)
1232 1362
51 kg of firewood carried by a 55kg
woman from government forest
Firewood- trees
on farms
Photo: Axel Fassio
Biochar & Briquettes
Dust
Drylands forest-
charcoal production

3. Top Lit Updraft
(TLUD) Gasifier
Three-stone
open fire
Reproduced by KIRDI
Reduces fuel use by 28% (biochar used in soil)
Reduces fuel use by 39% (char used as fuel)
Reduces PM2.5 by 90%
Reduces CO by 73%
Reduces CO2 by 26%
By Anderson and
Reed, 2004
• 150 farmers in highlands (Embu),
coast (Kwale), medium lowlands
(Siaya)
• 200 grams of biochar per cooking
• Application rate of 1-10t/ha
• Yield increase from 0.9 to 4.4 t/ha
and 33% for maize and kale
during a low rainfall year
Co-production of thermal
energy and biochar
Outer
casing Canister
Extinguisher
Combustion
chamber
Canister
holder
Skirting
Women’s (users) perceptions on functionality of the gasifier cookstove matter
User
experiences
shared with
KIDRI for
improvements of
the gasifier
Tabitha at Embu is self sufficient with firewood
from agroforestry. Applied 2.5t/ha biochar

4. Kenya’s Big 4 Agenda: Bioenergy-biochar system is a food,
health, manufacturing (kilns, stoves, instruments for
pruning/sizing firewood) and housing (cleaner kitchen) agenda
Research informing bioenergy-biochar development agenda in Kenya
NGO’s request to scale
the solutions.

5. Thank
you
Further reading
• Gitau, K. J., Mutune, J., Sundberg, C., Mendum, R. & M. Njenga, M.(2019). Factors influencing the adoption of
biochar-producing gasifier cookstoves by households in rural Kenya. Energy for Sustainable Development 52, 63–71.
https://www.sciencedirect.com/science/article/pii/S0973082618308913
• Gitau, J.K.; Mutune, J.; Sundberg, C.; Mendum, R.; Njenga, M. (2019) Implications on Livelihoods and the
Environment of Uptake of Gasifier Cook Stoves among Kenya’s Rural Households. Appl. Sci, 9, 1205.
https://www.mdpi.com/2076-3417/9/6/1205/pdf
• Gitau, J.K.; Sundberg, C.; Mendum, R.; Mutune, J.; Njenga, M. (2019). Use of Biochar-Producing Gasifier Cookstove
Improves Energy Use Efficiency and Indoor Air Quality in Rural Households. Energies 12, 4285.
https://www.mdpi.com/1996-1073/12/22/4285
• Mahmoud Y, Njenga M, Sundberg C, Roing de Nowina K (2021). Soils, sinks, and smallholder farmers: Examining the
benefits of biochar energy transitions in Kenya. Energy Res. Soc. Sci 75, 102033.
• Mendum, R. and Njenga M., (2018). Integrating woodfuels into agriculture and food security agendas and research in
sub-Saharan Africa (SSA). FACETS 3, 1-11. https://doi.org/10.1139/facets-2017-0032
• Njenga M, Gitau JK, Mendum R. (2021). Women’s work is never done: Lifting the gendered burden of firewood
collection and household energy use in Kenya. Energy Res. Soc. Sci. 77, 1020271.
• Njenga M., Sundberg C, Gitau JK, Mahmoud Y, Röing de Nowina K, Mendum R and Karltun E 2020. Biochar stoves
for socio-ecological resilience: Lessons from small-scale farms in rural Kenya. Policy Brief No 51. Nairobi, Kenya.
World Agroforestry (ICRAF). http://apps.worldagroforestry.org/downloads/Publications/PDFS/PB20040.pdf
• Njenga, M., Mahmoud, Y., Mendum, R., Iiyama, M., Jamnadass, R., Roing de Nowina, K., Sundberg. C., (2017),
Quality of charcoal produced using micro gasification and how the new cook stove works in rural Kenya. Environ
Research Letters, 12 (9). http://iopscience.iop.org/article/10.1088/1748-9326/aa7499
• Sundberg, C., Karltun, E., Gitau, J.K., Kätterer, T., Kimutai, G.M., Mahmoud, Y., Njenga, M., Nyberg, G., Roing de
Nowina, K., Roobroeck, D., Sieber, P. (2020). Biochar from cookstoves reduces greenhouse gas emissions from
smallholder farms in Africa. Mitigation and Adaptation Strategies for Global Change, 25(6), 953-967.
http://link.springer.com/article/10.1007/s11027-020-09920-7