## 3 Results and Discussion  
Based on the presented methodology, we assess the economic viability of the energy flexibility concept over a decade. We analyse the results for the following three scenarios: utilising electricity peaks from all of Slovenia for aluminium production (see Section 2.2); investing in a proprietary solar power plant of two different sizes and using the generated electricity for aluminium production (see Section 2.3); and investing in a private battery system, both standalone and in conjunction with the previous scenarios (see Section 2.4). This approach offers a comprehensive comparison of the viability of energy flexibility provision and traditional batteries. For this purpose, we first examine the prospects of national consumption and production obtained during the data preprocessing stage, which are shown in Figure 3. The prospects show the projected growth of national electricity consumption (blue lines) and PV production (yellow lines) for the next decade as an average characteristic day for each month. The latest data on consumption from 2022 were considered as baseline data from which the rest were extrapolated using data from the the national electricity distribution operator's development plan [32]. The electricity production from PV systems was obtained as the sum of the production from the locations of all transformers, to which the total amount of rated capacity of the solar power plants was allocated according to the share of the rated capacity of each transformer. The calculation for each transformer used long-term solar irradiance measurements from the nearest meteorological station in the TMY (Typical Meteorological Year) format, thereby capturing a more even distribution of generation at the national level. As anticipated, most surpluses are expected in the summer due to high production and low consumption levels. Nonetheless, by the end of the decade, some production surpluses might appear as early as April. Figure 3: _Cont._  
A detailed view of the load impact from electricity generated by PV systems is presented in Figure 4. Using the projected consumption profiles from Figure 3, the corresponding PV production profile for each year is subtracted. Negative values indicate peaks of PV-produced electricity available for aluminium smelting. As expected, the majority of these surpluses occur in the summer, with the amplitude of peak power often exceeding 500 MW during times of maximum irradiation. For a comprehensive economic analysis of the energy flexibility concept, the consumption of a large aluminium producer and the production of a hypothetical PV system need to be specified. In our case, the peak consumption of the large aluminium producer is set to 60 MW. This setting enables us to determine the size of an appropriate PV system. Specifically, we simulate the following two hypothetical local PV power plants: one designed to meet the expected demand of the large aluminium producer at full capacity (60 MWp) and another with 50% more capacity (90 MWp). The latter would allow the PV system to satisfy the entire demand during peak hours for most sunny days and potentially sell or store the excess energy in the battery system. Using the methodology described in Section 2.1.2, we estimated the PV output for both hypothetical systems over the next decade, with the PV systems' assumed characteristics listed in Table 1. \begin{table}
\begin{tabular}{l l} \hline \hline
**Parameter** & **Value** \\ \hline \(\beta\) & 35 \({}^{\circ}\) \\ \(\gamma\) & 0 (South) \\ \(C\) & 20\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: PV characteristics for the hypothetical PV systems. Figure 3: Prospects for national electricity consumption and production from 2022 to 2032, represented as an average characteristic day for each month. The bottom-most blue and yellow lines signify the consumption and PV production levels for 2022, respectively.