Overvoltage Challenges in Residential PV Systems in Poland: Annual Loss Assessment and Mitigation Strategies

In recent years, the rapid increase in installed photovoltaic (PV) capacity in Poland has created significant challenges for low-voltage distribution networks. Excess generation during peak solar hours frequently leads to local overvoltage conditions that exceed regulatory limits, causing PV inverters to disconnect from the grid. This phenomenon reduces the efficiency of distributed renewable energy integration and results in direct financial losses for prosumers. The present study quantifies these losses on an annual basis for a single-family household located in southeastern Poland, where overvoltage incidents occurred 614 times over 78 days in 2024. Real operational data from the residential PV installation were analyzed and complemented with detailed PVsyst simulations to determine the amount of energy curtailed due to inverter disconnections. The analysis revealed that daily energy losses can reach up to 22% of potential production, depending on the duration and frequency of overvoltage events. Furthermore, several technical and organizational measures are proposed to mitigate the issue, including grid reinforcement strategies and demand-side management. The findings highlight the necessity of addressing overvoltage in low-voltage distribution networks to ensure system reliability, enhance renewable energy integration, and maintain the economic viability of residential PV investments.