**7. Conclusions**

The proposed MDRed modeling scheme works as an optimization model which focuses on maximum demand (MD) shaving. This reduces the maximum demand and net consumption costs when using solar PV generation and battery systems. GA optimization results on MDRed modelling reveal that optimal sizing of the solar PV-battery system contributed to energy bill savings up to 20% of net consumption via solar PV self-consumption, 3% of maximum demand (MD) via MD shaving and 2% of surplus power supplied to grid via net energy metering (NEM) in regards to the Malaysian electricity tari ff scheme and cost of the overall system. In addition, the optimal battery sizing will be

based on the amount of MD savings annually with respect to the cost of the battery system including the bi-directional converters. If the load demand is reduced as a result of effective energy managemen<sup>t</sup> systems in place or low production in the factory or buildings, re-optimization may be useful to increase or maintain the current solar PV-battery size to maximize the net consumption and MD savings. In future, with higher demand for energy storage system and reduction in battery prices will lead to the realization of a higher rate of maximum demand shaving for commercial and industrial sector via MDRed modeling.

**Author Contributions:** Conceptualization, G.S. and P.S.; Methodology, V.K.R.; Validation, all co-authors; Formal Analysis, J.B.H.-N.; Investigation, P.S.; Writing-Original Draft Preparation, G.S., V.K.R. and P.S.; Writing-Review & Editing, P.S., P.K., and L.Z.; Supervision, P.S., L.Z. and P.K.; Funding Acquisition, L.Z. and P.K. All co-authors contributed substantially to the work.

**Funding:** This research received partial funding from EEEIC International, Poland.

**Acknowledgments:** The authors acknowledge the financial assistance from the Ministry of Higher Education (MOHE), Malaysia for the support to embark on renewable energy research.

**Conflicts of Interest:** The authors declare no conflict of interest.
