Determination of optimal power capacity for run of river hydro power plant based on flow duration curve using newton's interpolation method

Abstract

This paper determines the optimal power capacity installed for Run of River Hydro Power Plant (RORHPP). This is necessary in order to obtain an effective and efficient RORHPP, because the installed capacity will determine the investment and the energy produced. If the installed power capacity is too high, the investment cost will also be high, but if the installed power capacity is too low then the potential of water energy will be wasted. The main factors affecting the installed capacity of RORHPP are river flow and height of water fall. The river flow may change, while the water level falls steadily. Therefore, river flow is a variable parameter and the water falling level is a fixed parameter. Accurate determination of river flow discharge design is necessary to optimize RORHPP installed capacity. River flow discharge is obtained from hydrological data and catchment area which is then processed into flow duration curve (FDC). Based on the RORHPP design can be obtained the maximum power and energy generated by RORHPP, but this is not fixed at any time. The capacity factor (CF) is the ratio of real potential energy to the maximum energy generated in a year. Therefore, CF must be considered in determining installed power capacity. Furthermore, financial aspects such as NPV, IRR, BCR and BEP are also the considered parameters. Newton's interpolation method was used to determine CF, which is applied in RORHPP design of Lubuk Gadang. Simulation results show that installed capacity has low investment cost and high energy production as expected.