Hydropower production simulation at Kihansi River: a case study of lower Kihansi Hydropower project (LKHP)

Decline of hydropower generation at Lower Kihans Hydropower Project (LKHP) is caused by decrease of river flow and final water right conditions. The purpose of this study was to access the operations of the hydropower project and investigate the flow limit for financial viability of the project. A hydropower Simulation Model was developed and used in this study, the model has two modules the reservoir models and financial model. The reservoir model was used to access the operations of the hydropower project and estimate hydropower potential of LKHP. Financial model was used to determine the minimum annual energy required for financial viability of the project. The study shows that, there has been unnecessary annual spillage of 61.03mm equivalent to 80.5GWh. Operation strategy simulation favors continuous operations than peaking operations. The flow limit is 13.57m3/s considering transmission losses of 25%, achieved with annual generation of 720GWh. The average generation was 676.6GWh (2001 – 2005) and simulated was 757.1GWh showing that the generation was below the limit. Simulation with no environmental flows results on annual generation of 810GWh, indicating that project would be financially feasible. This analysis shows that financial viability of the project is affected operations of the reservoir, the environmental flows and high transmission loses which were not considered during design phase. Therefore the developers should improve reservoir operations by minimizing spillages and also minimize transmission losses.