Analysis of implications of a regulation on design discharge of run-of-river hydropower projects in Nepal

摘要

Abstract Nepal is richly endowed with water resources and hydropower is considered to be a major driver of its long-term sustainable economic development. The Government of Nepal has set a regulation that requires the design of run-of-river (RoR) hydropower plants (HPPs) with the discharge at the flow exceedance probability of 45. This paper analyzes the question of whether the regulation promotes the optimal sustainable development of RoR plants from a private developer’s perspective considering the case of four RoR HPPs. A spread sheet model was prepared to design different components, to estimate component?costs and to compute the energy generation and revenue for a range of design discharge. The optimal discharge was then determined based on the maximum net present value criterion. The study also analyzes the implications of the regulation for generation capacity, energy production, investment requirement and unit cost of electricity production of the RoR projects. The analysis shows that, in the domestic power market scenario, the power generation capacity at the optimal discharge in three out of the four HPPs would be 62–112 higher than that under the regulated design discharge. In the case of the electricity export scenario, the power generation capacity of all four HPPs at the optimal discharge would be 29–227 higher than that under the discharge regulation. Sensitivity analyses carried out with variations in key economic, financing, hydrological and project time overrun parameters mostly demonstrated the robustness of the basic findings.