Abstract:

Approximately 90% of Uganda’s population lives without access to electricity. The rural
households with no access to electricity incur high prices for imported kerosene and diesel. They
are vulnerable to indoor air pollution due to use of inefficient traditional energy technologies.
Thus, there is an important role for adopting a cost-competitive and a less polluting alternative
for electricity generation in Uganda.
A Husk Powered System (HPS) is an attractive option for rural electrification but has not been
widely adopted due to various techno-economic constraints. The purpose of the study was
therefore to provide a technical and economic evaluation of the viability of HPSs application in
coffee and rice processing centers in Uganda. A 34kWe pilot HPS, rice processing centers in
Pallisa and Butaleja, and coffee processing centers in Masaka, Lwengo, Ssembabule,
Bukomansimbi, Mubende and Mityana Districts were investigated. Technical evaluation of a
pilot HPS and estimation of the sustainability of husks for its operation were done using models
developed in Microsoft Excel. Investigation of local interest to adopt HPSs using Logistic
Regression Model (developed in SPSS), economic analysis using RETScreen and mapping of
potential sites using GIS, were also done.
The research revealed that overall energy conversion efficiency of HPS was 23.5% and 28.3%
when using rice husks and coffee husks as fuel source, respectively. Sustainability of husks for
HPS was high in coffee processing centers (104 - 1047kWc) than rice processing centers (10 -
249kWe), and the local interest to adopt HPS was high in all studied areas (odds ratio > 1).
Investing in HPS using rice husks and coffee husks as fuel would be economically viable with a
positive NPV (USS 4,039 and USS 15,275, respectively), B-C ratio > 1 (1.05 and 1.18,
respectively), an attractive PBP of 5.2 years and 4.6 years with a 10 year IRR of 13.20% and
16.4%, respectively. The cost of HPS-derived electricity using rice husks and coffee husks
(0.38214 and 0.38625 US$.kWhe_|, respectively) was lower than that of solar and diesel but more
expensive than national grid electricity for households.