**Acronyms**

*Green Energy Advances*

performance of the proposed SBMS increases when the PV system size is high and when the storage is undersized. In addition, a low value of Rsuff permits to increase

In the present work, smart BMS for residential users with a grid-connected PV-storage system is proposed. The BMS is Internet-connected and it downloads 1-day ahead weather forecasts, which are used to obtain a provisional energy production for the PV generator. These data are compared with load estimations, based on historical data. The result is a provisional energy balance, which is used by the BMS to select the best strategy to discharge batteries. In particular, the BMS preserves battery charge, when high load and low production is expected, and performs peak shaving, when loads exceed a user-defined limit. The combination of these methods results in a reduction in absorption peaks from the grid, with negligible variations in terms of self-sufficiency. The proposed BMS is efficient in case of undersized batteries, where the energy available in the storage is often not sufficient to supply all the loads. For example, in case of a family composed of two persons with a PV plant with rated power 4 kW and a storage of 2 kWh, the reduction in absorption peak from the grid during winter days varies from 39 to 50%. Other combinations of PV and storage sizes are investigated and improvements in

the use of peak shaving, without affecting the energy balance.

terms of peaks reduction are generally around 10%.

**88**

**5. Conclusions**

**Figure 12.**

**Table 3.**

**Combinations**

*Power profiles for case #2 with proposed SBMS.*

*C***bat (kWh)** *P***load,max (kW)**

*R***thres (%)**

#A 4 2 2 50 4.22 2.56 39 #B 2 1 2 70 4.42 4 9.5 #C 3 2 2 80 4.33 3.91 9.7 #D 5 5 1 60 4.10 3.74 8.8

**Standard BMS**  *P***max,absorbed (kW)**

**Proposed BMS**  *P***max,absorbed (kW)**

**Improvement (%)**

*P***PV,r (kW)**

*Results of the alternative configurations.*

