# Assessment of Impacts of Climate Change on Hydropower-Dominated Power System--The Case of Ethiopia
## 1 Introduction
Another study in Ecuador Modelled climate change effects on Ecuador electricity sector, which heavily depends on hydropower, shows that changes in water availability could induce a variation in electrical hydropower generation for supplying total electricity demand of between 29% and 86% [22]. The impact of climate change on the potential of several basins across South America was studied and investigated. Three downscaled global climate models were taken into consideration. For most regions in Brazil, the historical observations and regional climate change modelling results showed a significant reduction in rainfall and a rise in temperature. They have come to the conclusion that hydroelectric power plant output will likely decrease in the coming years [12]. The study used a partial equilibrium bottom-up optimization model (TIMES PT) to estimate the implications of climate change on the Portuguese electrical system by 2050, focusing on the impacts on water resource availability and hydropower generation. According to the findings, hydropower generation might decline by 41% by 2050, with higher electricity prices (up to a 17% rise) and higher greenhouse gas emissions (up to 7.2% increase) [23]. In the Upper Yangtze River Basin (one of the most vigorous hydropower regions in China), the effects of climate change and greenhouse gas emissions on hydropower supply and demand in the twenty-first century were investigated [14]. In drought affected areas, it is recommended to have ready concurrent other plants to compensate for the reduction in power generation due to climate change from hydropower plants. In Colombia, two partial equilibrium and two general equilibrium models were employed to discover potential energy system pathways. This research also revealed that climate change-related hydropower losses must be balanced by the emergence of other alternative technologies [13]. Using an integrated hydro reservoir and power system dispatch model, a study specific to Ethiopia reported the susceptibility of Ethiopian power systems to extreme hydrological circumstances. The findings showed that hydropower may assist in obtaining the lowest cost generation of electricity. Cost of power, on the other hand, was shown fluctuating greatly depending on many other parameters. It was discovered that, disregarding the cost of unserved energy, the low inflow scenario had a cost of electricity that was around four times more than the moderate inflow scenario [8]. In the future, climate change is expected to cause droughts to be longer and more intense in terms of precipitation shortage, which will decrease hydropower plants' capacity factor [5]. For hydrological forecasting and reservoir operation, a precise estimate of reservoir input is critical [24]. This article aims to show the impacts of climate change on hydropower generation and the environment in Ethiopia. It examines the impacts of severe drought to electricity generation by developing a scenario (named Drought Scenario) and comparing it with the reference scenario (named New Policy Scenario) using OSeMOSYS energy system modelling tool. Under drought conditions, the study looked at how electricity generation and its CO\({}_{2}\) emission would be altered in the future if reservoir capacity was halved (50%) due to drought. The characterization of the Drought Scenario is expected to enlighten decision-makers in the plan of future renewable power systems, including the provision of backup solutions.