# Simulation of Self-Consumption Photovoltaic Installations: Profitability Thresholds
## 3 Results
For example, Tables 4-8 represent, respectively, the maps for the annual photovoltaic production, the annual self-consumed energy, the annual savings achieved, the \(NPV\) and the \(Pay-back\), for an installation of 1000 Wp of installed peak power and 30 deg angle of obstruction. In them, the decrease of the variables is observed as the generator is oriented in different directions from the optimal one \(\left(\gamma_{opt}=0^{\circ},\ \beta_{opt}=15^{\circ}\right)\) and they offer the orders of magnitude for all simulations carried out. In general, a high symmetry is observed in the results with respect to azimuth. This is due to the uniformity of the demand curves during the hours of solar incidence. According to Table 4, it is observed that energy production decreases as the obstruction angle increases. Thus, Figure 6 shows the dependency of the optimal production achievable by a 1000 Wp installation as a function of the degree of obstruction. In all cases, as a consequence of Equation (1), energy production, other conditions being equal, will be proportional to its peak power. Figure 5: Hourly profiles of demand in: (**a**) January and (**b**) July [36]. \begin{table}
\begin{tabular}{l c} \hline \hline
**Parameters Considered** & **Value** \\ \hline Installation cost reflected in the power of the C\({}_{\text{U}}\) itself (EUR/Wp) & 1.1 \\ Overall return on investment and conversion losses: \(\eta\) & 0.8 \\ Price of energy purchased: \(p_{E}\) (EUR/KWh) & 0.16 \\ Compensation price for energy discharged to the grid: \(p_{C}\) (EUR/kWh) & 0.04 \\ Maintenance cost reflected in the power of the installation (EUR/Wp) & 0.02 \\ Annual discount rate: \(d(\%)\) & 3 \\ Inflation rate: \(i(\%)\) & 1 \\ Year-on-year increase in energy Price: \(\Delta p(\%)\) & 2.5 \\ Project useful life: \(n\) (years) & 20 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Parameters considered for the economic analysis of PV installations with self-consumption. Likewise, when comparing Table 5 with Table 4, it is verified that only the solutions with low productivity self-consume all their production. The possibilities of instant self-consumption are saturated when certain productivity limits are exceeded, precisely those that lead to discharges from the network. Thanks to these features, and their economic valuation, the savings achieved (Table 6) are not saturated to the same extent as instant self-consumption. From Table 9 it can be deduced that for installations with installed power of 1500 Wp, in the absence of obstructions (\(\zeta=0^{\circ}\)) all possible orientations give rise to positive \(NPV\). Likewise, it is evident that, as the value of the obstruction angle increases, the value of \(NPV\) decreases for all the installed powers. Although this occurs, both in the case of worst orientation and in the case of optimal orientation, the reduction is more pronounced in optimally oriented installations compared to those with worst orientation, where the values are negative, but with a low absolute value. Table 9 shows how in the situation of high obstruction the optimal \(NPV\) values are achieved with lower peak powers. Therefore, it is found that, as the degree of obstruction increases, installations with lower peak power are recommended, especially in the case of installations that are less well oriented.