# Assessment of Impacts of Climate Change on Hydropower-Dominated Power System--The Case of Ethiopia
## 4 Conclusions  
Ethiopia is already experiencing the effects of climate change-induced droughs on hydroelectric resources. Water levels at a reservoir also fell to their lowest level many times. Economic recovery in recent years meant that demand rapidly outpaced the limited supply, while periodic droughs disrupted hydroelectric power generation, exacerbating the problem. Overall, considering 50% capacity reduction due to drought in hydro plants, the total installed capacity has to increase by 5.9% compared to the New Policy Scenario from 169 GW to 179 GW. However, the electric production has to decrease by 2.7% compared to the New Policy Scenario from 517 TWh to 503 TWh, respectively. In both scenarios, renewable energy technologies constitute most of the power generation mix, which is 89% in the New Policy and 81% in the Drought Scenario, at the end of the modelling period. Drought phenomenon contributes to a significant impact on renewable energy technologies, especially hydropower and it reaches its peak electricity generation in 2056 (101 TWh), twelve years later after the New Policy Scenario reached its peak. Thus, considering climate change impacts, major changes in the electricity mix correspond to the strengthening of solar power technologies, which reach around 45% of total generation in Drought Scenarios. Different technologies are very differently affected by drought, which creates trade-offs or sometimes synergies between technologies. Following the hydropower, the other technologies will increasingly supply electricity up to 2065, nuclear for 13%, HFO for 3.4%, geothermal for 7%, wind for 6%, and biomass for 5%. While hydropower will continue to be the most common form of power generation until 2057, accounting for supplying 25.2% of all technologies. CSP will overtake hydropower in 2057 and account for supplying 32.5% by 2065. Due to the challenges of hydropower reduction, the scenarios showed a fundamental substitution in the structure of the renewable power sector, and even if there is a massive increase in electricity production from Solar PV, CSP, nuclear, and biomass, the supply will not meet the demand unless reinforced by fossil fuels. As a result, new power plants from non-hydro power technologies will be needed to sustain a growing population electricity demand. In addition, the government aims to achieve universal access and become an electricity exporter in the region by 2025, however, due to the severe drought, the electricity exports in the Drought Scenario will be 66.6% lower than the New Policy at the end of the modelling period. Therefore, drought may have a substantial impact on Ethiopia's ambitions plan to be EAPP  
The remaining balance between hydropower generation and electricity demand represents the remaining electric demand that must be met with other electricity resources. Satisfying the increased gap between hydropower supply and electricity demand will produce greenhouse gas emissions, however these can be significantly reduced if low-carbon resources are used. The results show Ethiopia's CO\({}_{2}\) emissions slowly increase in the Drought Scenario between 2015 and 2065 due to the mix of emission intensive technologies such as HFO as a substitute to loss of hydro generation although the demand can be satisfied while maintaining environmental standards. This study suggests that the climate-driven losses in hydropower must be compensated by the introduction of mega new infrastructures, which could provide sufficient power to secure the future Ethiopian electric system. The hydro dominated nation's energy mix should increase the share of non-hydro new plants equipped with modern technology and less vulnerable to drought is recommended. Future work could also further examine the potential impacts of climate change on other aspects of the power sector, such as wind and solar resources.