The climate change potential effects on the run-of-river plant and the environmental and economic dimensions of sustainability

In this work, we evaluate the environmental and economic sustainability dimensions of a run-of-river hydroelectric plant operation regarding environmental impacts and potential direct and indirect effects of climate change. Results suggest the generation of a vicious cycle of clean generation and dirty generation, enhanced by a positive feedback with climate change impacts. This cycle is triggered by the tradeoffs between environmental protection policies and the socioeconomic pressure for energy production, embedded in an energy production matrix that prioritizes fossil fuel-based production as responses to peak energy demand. The climate projections were generated by the Eta Regional Climate Model from the National Institute for Space Research. They were forced by the atmospheric simulations of the Interdisciplinary Climate Research Model (MIROC5) and the Hadley Center Global Environmental Model (HadGEM2-ES) under the RCP4.5 and RCP 8.5 emission scenarios. The MHD-INPE Distributed Hydrological Model was used to generate streamflow projections. Environmental impacts were assessed by accounting for carbon stock and sequestration, greenhouse gas emissions, and energy cost. Climate projections indicated reduced precipitation and increased temperature. The streamflow will present progressively reductions of the flow volume until the end of the century, which undermines the plant's ability to ensure firm energy and induce thermal plants' activation to supply the demand. This activation will lead to an increase in greenhouse gas emissions and an increase in the price of energy, which may lower the benefits in carbon stock associated with a run-of-river hydropower plant and negatively influence the reduction commitments assumed by Brazil.