## 4 Results and Discussion
For example, for the bus further away from the transformer, in the maximum load scenario, the voltage rises from 0.2337 kV to 0.236 kV, where in the shortest distance, the value changes from 0.2421 kV to 0.2439 kV. This means that the voltage unbalance is lower at the beginning of the feeder; hence, there is a tolerance to have more power at this point than at a more distant one. The balanced scenario limits of PV injection are presented in Figure 7. Having verified the most critical buses in Figure 5, where the voltage unbalance is more likely to be the highest (i.e., Bus 8, 9, and 10), the minimum load case is chosen, since it is the one where the highest unbalance is observed with the 3.5 kW simulation. Also, the nominal voltage limits of \(\pm\)10% are observed, since these limits could be broken before the voltage unbalance ones are. The results in Figure 7 show that the voltage unbalance limits of 2-3% are reached before the \(\pm\)10% nominal voltage ones. The maximum value of PV generation in this balanced scenario varies from 10 kW to 13 kW for the 2% and 3% limits, respectively. In terms of comparison with the values from the literature review of all of the MS, the ratio between the injected PV power and the total power requested to the upstream power transformer found in this study is 143 kW/430 kW = 33%, whereas the ranges found in the legislation vary from 0.4 to 1. However, a distinction must be made between injected power and PV installation power. The values found in this study refer to a maximum power injection per bus, whereas the limits of Member States refer to maximum PV connection per household. Figure 6: Voltage variation with distance with balanced (**a**) and unbalanced (**b**) PV distributions, simulated with maximum and minimum load and maximum load with no PV (Phase 3). The power injection simulations have been approached from the most conservative assumption. If a simultaneity factor (SF) lower than 1 is taken into consideration, than the maximum power could be increased, which is actually what many DSO use. This is because it is very unlikely that all of the consumers would have a PV panel generating the maximum power at the very same moment, and all with the same power demand. Another factor to take into consideration is the performance ratio (PR), which is also called quality factor, and refers to the overall performance of the system (orientation of the panels, losses, shades, dust in panels, etc.). This refers to the AC power that is actually provided by the system, which is very different from the peak power installed in the panels. Buses closer to the power transformer allow higher power connections than further ones due to the distances of cables and consequent voltage drops. Therefore, three-phase connections should be encouraged whenever possible. This would allow a more balanced voltage and a compensation of the voltage drop, especially in the most distant buses, and consequently higher power connections. Variables such as the length of the feeders, the load considered during the simulation, and the zero sequence shunt capacitance reactance of the cables influence the model's results the most. In terms of implications for public policies and proposed schemes, by identifying such limits of power injection, it is not desirable that in single-phase connections, similar schemes to net metering are used, especially with high penetration levels. This is because it makes an unnecessary or undesirable use of the grid, i.e., consumers may put power on the grid that they may use later, without actually having an incentive to consume when they generate power. A behaviour change towards an immediate consumption or local storage should be incentivised, and since there is a limit of power to be injected per bus, it should be optimised.