## 3 Case Study
### Self-Consumption: Spanish Legislative Framework  
As previously discussed, the proposed methodology can be applied to any legislative framework and according to the corresponding different national authority requirements. In our case, the aquifer is in Spain (Aquifer 23), and thus, the Spanish legislation based on RD 900/2015 is applied [31]. Through this directive, two types of self-consumption are defined: \((i)\)Type 1, lower than 100 kW of rate power; most individual pumping irrigation facilities can be classified as Type 1; and \((ii)\)Type 2, self-consumption with more than 100 kW rate power, injected into the grid at a price established by the electricity market pool. In line with the PV power plant capacities estimated and summarized in Figure 7, most communities of solar pumping irrigators would be considered as Type 2. In the case of Spain, taxes and fees that would reduce the final remuneration for the sale of energy must be imposed. These conditions represent a burden at a time of encouraging the implementation of solar solutions--mainly in this case that PV power plants connected to the grid cannot be amortized in a relatively short period of time. Indeed, the costs include a variable charges component associated with the system costs and determined from the variable terms, and a capacity payment component to  
Figure 7: PV power plant capacities for self-consumption scenarios: 1500 m\({}^{3}\)/ha and 3000 m\({}^{3}\)/ha. compensate for system support, compensation to the market and system operators, and interrupted service and adjusted service. It is also necessary to add the recent 7% tax on electricity generation (in September 2018 this was removed by the Spanish government) and the value added tax (VAT) of 21%. Tables 1-3 summarize the representative Spanish fixed, variable, and additional costs to be currently considered for the sale of energy. In Spain, the times of reduced power are usually distributed in three periods. However, for power higher than 450 kW, the Spanish electricity market offer six time periods (P1, P2, P3, P4, P5, P6). Figure 8 shows the electricity rates for the different time periods under the Spanish electricity system legislation. As an example, and for the systems described in this case study (direct PV solar pumping installations) and the selected crop water-need values--1500 m\({}^{3}\)/ha and 3000 m\({}^{3}\)/ha, the typical periods for this \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & \multicolumn{8}{c}{**Annual Fixed Tax (Euro/kWh)**} \\ \cline{2-7}
**Access Cost** & \multicolumn{2}{c}{**Period 1**} & **Period 2** & **Period 3** & **Period 4** & **Period 5** & **Period 6** \\  & P1 & P2 & P3 & P4 & P5 & P6 \\ \hline
2.0 (P \(\leq\) 10 kW) & 8.682019 & & & & & \\
2.1 (10 \(\leq\) P \(\leq\) 15 kW) & 15.083303 & & & & & \\
3.0 A (P \(>\) 15 kW) & 32.083923 & 6.212601 & 14.245468 & & & \\
3.1 A (1 kV to 36 kV) & 35.952537 & 6.717794 & 4.985851 & & & \\
6.1 A (1 kV to 30 kV) & 22.169359 & 7.844864 & 9.790954 & 11.926548 & 14.278122 & 4.882162 \\
6.1 B (30 kV to 36 kV) & 14.050921 & 3.782129 & 6.817708 & 8.953302 & 11.304876 & 3.525577 \\
6.2 (36 kV to 72.5 kV) & 9.082012 & 1.409534 & 4.372144 & 6.352856 & 8.073738 & 2.442188 \\
6.3 (72.5 kV to 145 kV) & 9.279523 & 2.525841 & 3.909548 & 5.479569 & 6.893947 & 1.911493 \\
6.4 (\(\geq\)145 kV) & 2.815509 & 0.000000 & 1.718359 & 3.457606 & 4.990376 & 0.970612 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Spanish fixed fees and taxes applied to the sale of surplus energy through self-consumption: requirements according to RD900/2015 [31].