# Assessment of Impacts of Climate Change on Hydropower-Dominated Power System--The Case of Ethiopia
## 3 Result and Discussion
### Electricity Supply Mix Drought
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**ELC Supply (GWh)**} & \multicolumn{5}{c}{**Drought Scenario**} & \multicolumn{5}{c}{**New Policy Scenario**} \\ \cline{2-8}  & **2015** & **2030** & **2050** & **2065** & **2030** & **2050** & **2065** \\ \hline Biomass & 783 & 1410 & 10,013 & 25,296 & 1410 & 2314 & 17,597 \\ LFO/HFO & 949 & - & - & 16,536 & - & - & 4732 \\ Gas & - & - & 1024 & - & - & 10,716 & 3604 \\ Nuclear & - & - & 37,230 & 66,209 & - & 11,169 & 63,500 \\ Hydro & 5299 & 41,855 & 90,570 & 101,964 & 76,895 & 183,104 & 183,104 \\ Geothermal & 60 & 14,341 & 35,040 & 35,040 & 14,341 & 35,040 & 35,040 \\ Wind & 925 & 14,225 & 28,700 & 28,700 & 1310 & 28,700 & 28,700 \\ Solar PV & 18 & 10,807 & 61,937 & 66,365 & 3662 & 43,137 & 66,365 \\ Solar CSP & - & - & 43,407 & 163,058 & - & 3523 & 114,362 \\ Total & 12,151 & 82,638 & 307,920 & 503,167 & 98,186 & 305,081 & 517,004 \\ RET share (not & 97\% & 97\% & 90\% & 81\% & 100\% & 98\% & 89\% \\ includes Nuclear) & & & & & & & \\ Djibuti exports & 416 & 754 & 520 & 130 & 832 & 608 & 389 \\ Kenya exports & 0 & 11,195 & 7746 & 4157 & 11,651 & 11,474 & 7274 \\ Sudan exports & 416 & 13,693 & 12,672 & - & 25,006 & 16,141 & 9415 \\ Tanzania exports & 0 & - & 725 & 534 & 2143 & 2143 & 888 \\ Exports & 832 & 25,642 & 21,663 & 4821 & 39,632 & 30,366 & 17,966 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of Electricity supply of Drought and New Policy Scenario. other renewable technologies (PV and CSP) will enter the system and compensate for the generation deficit. The Drought scenario electricity generation from hydropower technology is expected to reduce between 44.3% and 50.5% during the modeling period compared to New policy scenario. In the case of Drought, hydropower reaches its peak in 2056 (101 TWh), twelve years later after the New Policy Scenario reached its peak. Following the hydropower, the other technologies will increasingly supply electricity up to 2065, with solar PV accounting for 13% (66 TWh), CSP for 32.5% (163 TWh), nuclear for 13% (66 TWh), Heavy Fuel Oil (HFO) for 3.4% (16 TWh), geothermal for 7% (35 TWh), wind for 6% (29 TWh), and biomass for 5% (25.3 TWh). While hydropower will continue to be the most common form of power generation until 2057, accounting for supplying 25.2% (101. TWh) of all technologies, CSP will overtake hydropower in 2057, accounting for supplying 32.5% (163 TWh). However, biomass and HFO significantly come to the electricity mix to 25.3 TWh and 16.5 TWh in Drought Scenario compared to 17.5 TWh and 4.7 TWh in New Policy Scenario in 2065, respectively (See Figure 4). Consequently, power generation drops due to droughts can be (at least partially) compensated for by technologies with different technology mixes, which are less or even positively affected by drought. The maintenance of an adequate supply of energy in a region depends on how its energy mix is composed, taking into account the existence and availability of a set of energy sources. In the Drought Scenario, the Electricity supply mix, dominated by hydro, gradually diversifies as solar PV, CSP, biomass and from non-renewables such as HFO increasingly make inroads into the system. The energy demand mostly covered by widespread deployment of renewable energy sources between 81 and 97% of the total generation between 2015 and 2065, respectively. The performance of each individual source (hydro, wind and solar) over a period varies due to its seasonality, which may require emission intensive technologies to add to the mix. In comparison to the New Policy Scenario, the use of renewable energy in the electrical mix results in a reduction of up to 8% at the end of modeling period. The loss in hydropower  
Figure 4: Comparison of electricity supply mix between Drought vs. New Policy Scenario. generation in Drought Scenarios, along with the inadequacy of other renewables' capacity to meet demand, means that non-renewable technologies such as HFO is reinforced by 12 TWh to supply mix.