Sinovoltaics, a Netherlands-based quality assurance and technical advisory firm for PV and energy storage systems, has released Edition 4 of its PV Inverter Manufacturer Ranking Report. According to Sinovoltaics, the report has evaluated the financial strength of more than 30 PV inverter manufacturers using Altman Z-Scores. The analysis has used publicly available financial data covering the period from December 2022 to September 2025. The methodology has classified manufacturers into Safe (Z > 2.6), Grey (1.1–2.6), and Distress (Z < 1.1) zones. As of September 2025, the Safe Zone has included 19 manufacturers, compared with 15 in the previous edition. KSTAR has ranked highest with a score of 7.97, followed by APSystems (6.48), Delta Electronics (6.47), Sinexcel (6.09), and Eaton (5.38). Sungrow has improved to 4.81, while Enphase has declined to 2.21 and SolarEdge has fallen to −1.29. Sinovoltaics has stated that the ranking supports supplier evaluation based on financial reliability and long-term warranty enforceability.