Recent research published in ‘IEEE Access’ highlights a significant advancement in managing overvoltage issues caused by rooftop solar photovoltaic (PV) systems in Australia. The study, led by Vanika Sharma from the University of South Australia, proposes a novel method to reduce the active power curtailment that often occurs when excess solar energy is fed into the grid, which can lead to overvoltage conditions in distribution networks.
As more households install rooftop solar systems, they tend to export surplus energy back to the grid after meeting local demand. This influx of energy can sometimes cause voltage levels to exceed acceptable limits, prompting grid-connected PV inverters to either curtail their power output or shut down entirely to prevent safety hazards. The Australian standard AS/NZS 4777.2.2020 mandates that PV inverters must employ real and reactive power quality response modes to mitigate these overvoltage issues. However, these measures often lead to lost revenue for solar system owners due to curtailed energy production.
Sharma’s research introduces a solution that involves utilizing reactive power support from local battery inverters. By allowing battery inverters to provide reactive power without affecting their active power flow, the reliance on PV inverters can be significantly reduced. This means that when the grid voltage exceeds the threshold, the battery inverter can step in to help manage the situation. If the battery inverter cannot provide enough reactive power, then the PV inverter’s response modes are activated as a secondary measure.
The study tested this method on an 11-kV distribution feeder in South Australia, demonstrating that the combination of battery and PV inverter support can effectively eliminate overvoltage issues and the associated financial losses. “By integrating battery inverters with PV systems, we can not only enhance grid stability but also ensure that solar energy producers can maximize their output,” Sharma noted.
This research has substantial commercial implications, particularly for the battery energy storage sector and solar energy providers. As the demand for renewable energy solutions grows, the ability to manage overvoltage and maximize energy export can lead to increased profitability for solar system owners. Furthermore, energy storage companies could see heightened interest in developing systems that can provide reactive power support, creating new market opportunities.
Additionally, the findings suggest that selecting lower source bus voltages during periods of high solar radiation can also mitigate overvoltage problems. This insight could lead to new strategies for grid management, allowing utility companies to optimize their distribution networks in alignment with renewable energy production.
Overall, the collaborative approach of integrating battery storage with solar PV systems not only addresses technical challenges but also opens the door for enhanced economic viability in the renewable energy landscape.
