## 4 Results
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline  & & & & & & & & & & & & & \\ \cline{2-11}  & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** \\ \hline
**Climatic Zones** & **A3** & **A4** & **B3** & **B4** & **C1** & **C2** & **C3** & **C4** & **D1** & **D2** & **D3** & **E1** \\ \hline Heating demand & 4 & 3.3 & 4.45 & 6.52 & 22.5 & 7.71 & 10.3 & 10.3 & 28.4 & 26.3 & 16.1 & 34.8 \\ \hline Cooling demand & 3.64 & 5.89 & 6.82 & 7.7 & 0 & 3.39 & 4.33 & 10.8 & 0 & 1.44 & 4.97 & 0.41 \\ \hline Heating CO\({}_{2}\) emissions & 1.34 & 1.11 & 7.39 & 2.19 & 7.57 & 2.59 & 3.47 & 3.47 & 9.54 & 8.84 & 5.42 & 11.7 \\ \hline Cooling CO\({}_{2}\) emissions & 1.2 & 1.94 & 2.25 & 2.54 & 0 & 1.12 & 1.43 & 3.56 & 0 & 0.47 & 1.64 & 0.27 \\ \hline Estimation of life cycle cost & 21.7 & 19.6 & 33.5 & 24.2 & 50.4 & 46.9 & 58.2 & 53.2 & 97.3 & 94.2 & 71.1 & 115 \\ \hline Energy Efficiency Index & 0.41 & 0.44 & 0.43 & 0.41 & 0.42 & 0.39 & 0.38 & 0.45 & 0.45 & 0.41 & 0.43 & 0.46 \\ \hline Energy rating & B & B & B & B & B & B & B & B & B & B & B & B \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Building envelope optimization. In the example above, each proposed solution would consist of a complete list of decisions based on the photovoltaics technologies. The selection of the inverter is the same in all cases (price 0.02 \(\upxi\)/Wp, power of 12 kW and efficiency of 85%). The demand is defined in the first step, reducing the final energy consumption (heating and cooling), LCC, EEI and Energy Rating in the second step. The resolution is built with a dataset of European solar panels obtained from www.enfsolar.com, in which all the necessary data for the analysis is obtained. The database can be expanded with solar panels of greater efficiency and power, so that the application of the methodology would obtain better results. In Table 6, there are three cases in which 100% use of renewable energies is not reached, so other renewable energies that could be more efficient in the area, such as wind energy, could be applied. The solution could be a mix of renewable energies, thus, some energies could be complemented with others to reach the necessary demand. In these three cases, sufficient energy is not achieved due to space limitations, high demand and climatic characteristics. On the other hand, radiation (Table 4) and demand (Table 6) is different for each climate zone. Particularly, the demand in southern Spain is lower and there is good radiation, so the number of panels is lower. Even so, in all locations the highest energy rating is obtained, although the LCC is lower because no CO\({}_{2}\) is generated, nor conventional electricity is used. In these cities, Lugo (D1), Valladolid (D2) and Soria (E1), where there is no 100% use of renewable energy, the LCC is increased because conventional electricity is used. Figure 4 shows the LCC regarding the EEI for different solar panels in the selected cities of each climatic zone. It can be observed that in the climatic zones with high demand and low radiation, not all the solar panels can be used to minimize the EEI of the building with low LCC.