In the latest Energy Storage Inspection 2026 conducted by the Berlin University of Applied Sciences and Technology (HTW Berlin), RCT Power is once again among the manufacturers with the most efficient photovoltaic storage systems. In the 10 kW power class, the system achieves a System Performance Index (SPI) of 96.4%, placing it once again among the top-performing PV storage systems on the market.
For the seventh consecutive time, the RCT Power system ranks among the top systems in the overall SPI evaluation. At the same time, the results show that SPI requirements continue to serve as an important benchmark and that manufacturers are continuously developing their technologies to further optimize system efficiency.
In previous years, RCT Power has already achieved several top rankings and has been named overall test winner six times in the HTW Berlin Energy Storage Inspection. The company is therefore particularly pleased to remain among the leading systems in the study even after many years of participation with the same system.
The annually published study compares the energy efficiency of PV battery systems using SPI and is considered one of the most important independent efficiency benchmarks in the residential energy storage market. The results show that systems from RCT Power achieve efficiency class A, placing them among the most powerful solutions in the test. The high efficiency enables particularly effective use of solar power and helps with maximizing both self-consumption and the economic benefits of photovoltaic systems.
The HTW study regularly analyzes a wide range of storage solutions available on the market, creating transparency for installers, professional partners, and end customers. The analysis shows that system efficiency can vary significantly and that high-performance storage systems make an important contribution to the optimal use of solar energy.
RCT Power also continues to achieve outstanding results in several technical categories. The system once again reaches the top value for settling time. In addition, RCT Power clearly leads in conversion efficiency at low discharge power—an operating condition that frequently occurs in practice. The system also demonstrates particularly high efficiency in the BAT2AC and AC2BAT conversion efficiencies, an aspect that is becoming increasingly important, especially in the context of tariff-based charging and discharging.
Pei-Fen Hsiao, Managing Director of RCT Power, emphasizes the importance of the study: “Independent studies such as the HTW Berlin Energy Storage Inspection provide valuable guidance for installers and operators of PV systems. We are very pleased that our systems once again rank among the most efficient solutions on the market.”
