## 3 Results
### Energy Demand
#### 3.1.3 Influences of Current and Future Extreme Weather Conditions  
Table 7 shows the space cooling electricity consumption of the old and new building base cases with the split cooling unit in April-September of 2018 (HWS2018) and April-September of the mid-century (HWS2050); these represent extreme summer weather conditions in the current and future climate. The effects of the heatwaves on the electricity consumption for space cooling were calculated for each building type. Comparisons were made both between the current and future heatwaves and against the average climate, using the TRY2020 and TRY2050 weather data as baselines. According to the simulation, the heatwave in 2018 increased the cooling electricity consumption significantly more in  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & **Cases** & **District Heating** & \multicolumn{4}{c}{**Electricity**} & \multicolumn{4}{c}{**Difference (\%) in Comparison to Ref-Old**} \\  & & **Total** & \begin{tabular}{c} **Space and** \\ **Ventilation** \\ **Heating** \\ \end{tabular} & **Total** & **Cooling** & **Total** & \begin{tabular}{c} **Space and** \\ **Ventilation** \\ **Heating** \\ \end{tabular} & **Total** & **Cooling** \\ \cline{2-10} \multirow{6}{*}{\begin{tabular}{c} **Ventilation** \\ **Ventilation** \\ **Heating** \\ \end{tabular} } & Old-base with & 159.5 & 117.1 & 34.9 & 4 & \(-11.9\) & \(-15.5\) & 3.6 & 42.9 \\  & Old-South & 155.8 & 113.5 & 30.9 & 0 & \(-13.9\) & \(-18.1\) & - & - \\  & Old-No building & 156.9 & 114.5 & 30.9 & 0 & \(-13.3\) & \(-17.4\) & - & - \\  & \begin{tabular}{c} Old-Window \\ opening \\ \end{tabular} & 159.7 & 117.3 & 30.9 & 0 & \(-11.8\) & \(-15.4\) & - & - \\  & & & & & & **Difference (\%) in comparison to Ref-New** \\  & & & & & & & **cooling 2020** \\  & New-base with & 70.4 & 28 & 37.8 & 3.4 & \(-8.1\) & \(-18.1\) & 2.2 & 30.8 \\  & \begin{tabular}{c} New-South \\ **New-No** \\ building shading \\ \end{tabular} & 69.1 & 26.7 & 34.4 & 0 & \(-9.8\) & \(-21.9\) & - & - \\  & New-Window & 69.2 & 26.8 & 34.4 & 0 & \(-9.7\) & \(-21.6\) & - & - \\  & \
\begin{tabular}{c} New-Window \\ opening \\ \end{tabular} & 70.5 & 28.1 & 34.4 & 0 & \(-8.0\) & \(-17.8\) & - & - \\  &
\begin{tabular}{c} New-Cooling \\ ventilation and \\ ventilation boost \\ \end{tabular} & 71.0 & 28.9 & 38.8 & 2.6 & \(-7.3\) & \(-15.5\) & 4.9 & 0 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Annual total purchased energy (\(k\)Wh/m\({}^{2}\) a), in the projected future climate under the RCP4.5 scenario (TRY 2050).  
the old than in the new building. Although small in absolute terms, the simulated space cooling electricity is even 37.5% (17.6%) higher for the heatwave summer 2018 than for the future average climate (TRY2050) in the old (new) building, respectively.  
In the heatwave summer 2018, the simulated space cooling electricity in the old and new buildings, respectively, was 96.4% and 53.8% higher than the results for the average climate TRY2020. It also exceeded the results for the average climate of 2050 (by 37.5% for the old and by 17.6% for the new building). In the heatwave summer 2050, the space cooling electricity will be 31% and 28% higher than the results with HWS2018. This shows that heatwaves cause a significant increment on the electric grid. Thus, in the future, there will be crucially important issues concerning the effects of heatwaves on the electric power supply.