Optimization of surplus electricity management from municipal photovoltaic systems: virtual storage vs battery systems

This study presents a comparative analysis of two models for managing surplus electricity generated by photovoltaic (PV) systems installed on eight municipal buildings in a Macedonian municipality. The first model is based on distributing the surplus electricity among 20 municipal buildings, utilizing them as a virtual storage to maximize local consumption of the generated electricity. The second model involves storing the surplus electricity in battery systems at each PV-equipped building and using the stored electricity the following day within the same building, while any surplus is sold on the market. For the purpose of the analysis, electricity consumption of the 28 municipal buildings and electricity production from the PV systems data were obtained from a municipal representative and allocated on an hourly basis using the standard load curve from EVN Macedonia and simulations performed with the licensed PV*SOL premium software. Financial analyses were conducted based on electricity prices from the HUPX electricity exchange for the year 2024. This study provides an assessment of the economic and technical advantages and drawbacks of both approaches, evaluating their impact on municipal energy independence, financial feasibility, and the optimization of renewable energy management.