Impact of climate change on hydropower generation in Thac Mo hydropower plant

Abstract

     Hydropower makes it an important contributor to Vietnam’s energy grid, accounting for about 40% of the total national electricity production. However, hydropower generation is very sensitive to changes and variability in climate variables, particularly rainfall and evaporation. Climate change, which substantially impacts climate variables and runoff, has a significant influence on the inflows to reservoirs at hydropower plants, and their hydropower generation. Therefore, this study aims to conduct a quantitative assessment of the climate change impact on the future hydropower production, demonstrated for the Thac Mo hydropower Project. This study uses a GR4J hydrological model coupled with a hydropower simulation model to simulate future inflow and hydropower generation at the hydropower plant under climate change. Six Regional Climate Models (RCMs) from The Coordinated Regional Downscaling Experiment (CORDEX) with two representative concentration pathways (RCP2.6 and RCP8.5) scenarios are bias-corrected by quantile mapping method to project changes in future rainfall and temperature for the study area. Our quantitative assessments indicate that climate change is expected to alter the rainfall regime, decrease the average annual inflow and hydropower generation by 20 – 40% by the middle of the 21st century.