## 6 Results
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & & **Case A (“Only DG”)** & & **Case B (“DG + End-Users”)** & \\ \hline \multirow{3}{*}{**Feeder**} & **Feasible Points** & **Feasible Points** & **Unfeasible Points** & **Feasible Points** & **Feasible Points** & **Unfeasible Points** \\  & **(Green)** & **with Q Control** & **(_Red)** & **(_Green_)** & **with Q Control** & **(_Red)** \\ \cline{2-7}  & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** & **(\%)** \\ \hline R1 & 79.9 & 2.7 & 17.4 & 66.8 & 5.7 & 27.5 \\ R2 & 100.0 & 0.0 & 0.0 & 89.2 & 5.0 & 5.8 \\ D3 & 100.0 & 0.0 & 0.0 & 100.0 & 0.0 & 0.0 \\ U4 & 100.0 & 0.0 & 0.0 & 97.0 & 0.0 & 3.0 \\ U5 & 100.0 & 0.0 & 0.0 & 96.1 & 0.0 & 3.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Operating point occurrences differentiated for each feeder in the Case Study. from overvoltage issues), and many unfeasible points constitute the potential negative \"Delta Active Power\" (\(-1\) MW). However, in some conditions, the Q control can avoid the voltage problems, and a few offers can be accepted, taking into account the additional cost needed for the Q contribution (\(0\div 0.5\) MVar). The green points corresponding to negative \"Delta Reactive Power\" refer to electrical conditions on which the generation injects active power with a non unitary power factor (e.g., wind and CHP units). From another point of view, Figure 4 reports the R1 feeder potential active power profile in all the considered representative days. It shows that, in many time intervals, the feeder has a reverse flow to the main transformer (negative values), but the active power feasible is limited to about 3.8 MW (Figure 4). The majority of unfeasible points are concentrated in the lower part of the profile (increase in power production). Still, some unfeasible points can also be found in the upper part, as discussed in Figure 3. Analysing the differences between the representative days, the unfeasible conditions due to an excessive reduction in the DG production are more frequent in the winter and autumn seasons, according to the load/generation coincidence profiles. Figure 4: Potential P profile during all the representative days, feeder R1—case A (“only DG”). Figure 3: P-Q variations during all the representative days, feeder R1—case A (“only DG”). In the proposed Case Study, only feeder R1 has critical operating points, while the other feeders are completely feasible (Table 3). Therefore, the other feeders are not described in detail. For example, Figure 5 reports the second rural feeder (R2) potential active power profile in all the considered representative days, without reverse flow conditions and fully feasible. In Figure 6 the same shape is shown for the urban feeder (U4--Figure 2): again, it is completely feasible despite some hours of the year in reverse flow. As indicated in Chapter 0 and the first part of this Section, the last columns of Table 3 report the occurrences of the states of the calculated operating points by also considering the contribution of the end-users to the market potential (case B). Figure 5: Potential P profile during all representative days, feeder R2—case A (“only DG”). Figure 6: Potential P profile during all representative days, feeder U4—case A (“only DG”). First of all, it is worth noticing that the occurrence of Q control feasible (orange) and unfeasible (red) points increases in the case of B in comparison with case A (Table 3). This fact is due to the increased number of operating points on which it is subdivided by the larger range of the market potential due to the added flexibility offered by the end-users. In other words, some operating points in case B have not been analysed in case A because it depends on the end-users' offers. Nevertheless, the end-user engagement allows a more extensive flexibility volume to be obtained compared to the case with only the DG participation. To confirm the last sentence, Figure 7 reports the R1 feeder potential active power profile in all the considered representative days for case B.