**5. Roof-top photovoltaic alone**

Analysis has been considered for each residential customer having 200 W (watts) of installed roof-top photovoltaic (RTPV) capacity, an overview of this connection can be seen in **Figure 2**. It is assumed that if the power generated by the RTPV would exceed their instantaneous demand then the excess power would feed into the electrical grid.

**Figure 2.** *Conventional RTPV installation [14].*

*Battery Energy Storage Systems and Rooftop Solar-Photovoltaics in Electric Power Distribution… DOI: http://dx.doi.org/10.5772/intechopen.99248*

**Figure 3** shows the comparison of RTPV and the network normal power curves. The network normal (P) is the load profile for the study. It can be seen that during daylight hours RTPV dispatches power; hence the reduction of power can be seen when compared to the network normal curve.

From this analysis, it is seen that the Utility loses 5.76% in revenue resulting from an overall reduction in dispatched power. While the supplied power to the customer from the utility is reduced by 5.8%, referring to data in **Figure 4**. Hence the

**Figure 3.**

*Active power of NB36 with 200 W RTPV penetration, considered for a winter weekday.*

**Figure 4.**

*Sending active power, power consumed by customers and P losses, considered for a winter weekday.*

benefit to the customer is credited to the RTPV injection. The disadvantage when considering RTPV alone is that it feeds only during daylight hours, there is no effect to the network morning and evening peaks period; the peak violations mainly exist during the evening peak time. This leaves the question of what will be the influence of RTPV combined with BESS.
