Abstract:
This dissertation presents the analysis of Quthing River and Letseng-la-Letsie for hydropower
potential in Quthing district in Lesotho. Electrical power deficit in the country is more prominent
in rural areas like Quthing District. This calls for assessment of electrical sources in the vicinity of
rural area load centers to inform policies for electrical production so as to curb power deficit
problem. Mountain Rivers like Quthing River with steep slopes or gradients naturally provide good
head which needs to be assessed along with its flow rates. Furthermore elevated dams like
Letseng-la-Letsie can also provide a natural good head which needs to be assessed alongside with
its discharge rates. The assessment was carried out by employing catchment area method to asses
flow rates since the abstraction points of the study areas were ungaged and lacks data. The maps in
association with QGIS were used to evaluate heads of the study areas and lastly TURBNPRO was
used to determine power outputs from the study areas.
The resultant net head for Quthing River was found to be 164.15 m while the net head for Letsengla-Letsie was 159.23 m. The design flow rate of Quthing River was found to be 0.58 m3/s while
that of Letseng-la-Letsie was 0.1 16 m3/s. The results from TURBNPRO showed that the power
output for Quthing River turbine was 815 kW while the power output for Letseng-la-Letsie turbine
was 221 kW. Using typical hydro-electric generators efficiency of 99% and typical capacity factor
for Africa of 0.49, the capacity from Quthing River was found to be 807 kW with annual energy
of 3.46 MWh. The capacity for Letseng-la-Letsie was found to be 0.22 MW with annual energy of
0.95 MWh.
