In the quest to integrate more renewable energy into our power grids, researchers are finding innovative ways to boost the capacity of low-voltage (LV) distribution grids to host solar power. A recent study published in the IEEE Access journal, conducted by Helio M. A. Antunes from the Graduate Program in Electrical Engineering at the Federal University of Espirito Santo in Brazil, sheds light on how decentralized battery energy storage systems (BESS) can significantly enhance the hosting capacity of these grids.
The challenge lies in voltage regulation. As more photovoltaic (PV) rooftop units are installed, the risk of overvoltage increases, which can destabilize the grid. Traditionally, PV inverters are equipped with volt-var (VV) and volt-watt (VW) control functions to manage this issue. These controls help maintain grid voltage within acceptable limits, but they often lead to energy curtailment, meaning some of the generated solar power goes unused.
Antunes’ research proposes a more efficient solution: decentralized BESS. These small, strategically placed batteries can store excess energy without causing additional current circulation within the grid. “The use of decentralized BESS near nodes sensible to overvoltage becomes appealing,” Antunes explains, “as it stores energy without creating current circulation within the grid.”
The study, conducted using OpenDSS software, evaluates the hosting capacity of a generic LV grid with PV units and compares scenarios with and without VV and VW controls. The results are promising. By sizing BESS units at about 5-10% of the PV power capacity, the research shows that it’s possible to reduce revenue impacts and increase hosting capacity by over 30%.
The implications for the energy sector are significant. As solar power continues to grow, utilities and grid operators are constantly seeking ways to accommodate more renewable energy without compromising grid stability. Decentralized BESS offers a viable solution, potentially revolutionizing how we integrate solar power into our energy infrastructure.
Antunes’ methodology provides a clear path forward for sizing these BESS units, making it easier for energy companies to implement this technology. “This paper contributes with a comprehensive study that evaluates the hosting capacity of a generic LV grid comprised of PV units with embedded VV and VW control functions,” Antunes states, highlighting the practical applications of the research.
As the energy sector continues to evolve, this research could shape future developments in grid management and renewable energy integration. By optimizing the use of decentralized BESS, we can move closer to a future where solar power plays a dominant role in our energy mix, all while maintaining the stability and reliability of our power grids. The study, published in the IEEE Access journal, which translates to the Institute of Electrical and Electronics Engineers Access, provides a robust foundation for further exploration and implementation in the field.
