Climate-informed decision-making for hydropower resilience in the central Himalayas

Abstract:

Hydropower is a major renewable energy source across the globe. Climate change is likely to alter river flows in several parts of the world, which in turn will impact hydropower generation capacity. Sound understanding of future hydroclimatic conditions is critical for informed decision-making in hydropower generation. Previous studies provide valuable new insights on the impacts of climate change on hydropower generation, but often sample only a relatively small subset of known unknowns (e.g., climate models, model parameters and model structure). These choices can drastically undersample the projected river flows, and can lead to poor hydropower operation decisions. We develop an integrated modeling framework that is capable of simulating the effect of deeply uncertain hydroclimatic projections on hydropower generation. The framework consists of greenhouse emission scenarios, global climate projections, hydrological model, statistical model and hydropower impact assessment. The framework samples future climate forcing scenarios and climate models to force a hydrologic model and generate river flow projections. The projected river flows are then used to simulate future hydropower generation. We apply the integrated, multi-model, and multi-scale framework on mountainous catchment upstream of major hydropower stations in western Nepal. Our results provide insights on how hydropower generation would change under future climatic conditions, and is of practical importance for informing hydropower investment and operational decisions in a changing climate.

Keywords: climate change; hydropower generation; hydroclimatic projection; uncertainty quantification