Energy flexibility analysis for photovoltaic solar system with battery

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The energy flexibility concept can be used to assess the performance of different systems and control strategies to implement demand-side management for the smart grid. Due to increasing penetration rate of onsite solar electricity generation, it is necessary to assess the impact of adding hybrid solar system with battery on energy flexibility. Integrating batteries within solar photovoltaic (PV) systems enables to control the power flow dispatch (based on supplied electricity and required load). In addition to modifying the electrical load profile (e.g. peak shaving, load shifting), battery storage units add resiliency to system in the case of power failures. This paper aims to investigate the energy flexibility of a typical Canadian house equipped with a PV plus battery system by comparing Key Performance Indicators (KPI). For this purpose, a detailed model of the building (building envelope and all-electric HVAC system) as well as solar electrical system (PV arrays, charge controller, inverter and battery) is implemented in TRNSYS. Results show that the yearly KPIs (self-generation and self-consumption) are greatly improved by adding batteries to a conventional grid-tied PV system, with a saturation effect for larger battery capacities. Dynamic KPIs indicating the response to 1-h upward and downward flexibility event show that the conventional inverter control strategies (grid-support and UPS) present results at the two opposite ends of the spectrum, the UPS strategy offering the highest downward flexibility and the grid-support strategy offering the highest upward flexibility. Both KPIs are highly variable depending on the time of day and day of the year, with relatively stable median values.

Recommended citation: Barzegar B, Zhang K, Kummert M (2018). Energy flexibility analysis for photovoltaic solar system with battery. In: Proceedings of eSim 2018, Montreal, Canada, May 9–10, pp. 183–192.