BERLIN, March 7, 2026 /PRNewswire/ — Fox ESS, a leading provider of renewable energy solutions, announced a significant milestone in energy storage efficiency. The company achieved a record System Performance Index (SPI) of 97%, securing the top position and achieving an Efficiency Class A ranking in the storage category by HTW Berlin and AQUU Research.
HTW Berlin, a leading German university of applied sciences, is internationally recognized for its rigorous research in energy storage technologies. Its annual “Energy Storage Inspection” reports are considered among the most credible assessments in Europe, comprehensively evaluating energy storage systems under practical conditions.
“This 97% SPI is more than just a number; it embodies our unwavering commitment to innovation and excellence in energy storage solutions. We are committed to advancing the Energiewende initiative, ensuring everyone can benefit from reliable and sustainable solar energy. said Christoph Schön, Managing Director of the DACH region at Fox ESS.
Record performance
The latest report looked at 12 systems, 8 of which were rated using the SPI (10 kW) metric. The Fox ESS system, including the PQ-H3-Ultra-10.0 inverter and EQ3300-5 battery, achieved a breakthrough SPI of 97%. This high efficiency reflects the optimized design of Fox ESS, which minimizes energy conversion losses and improves overall system reliability for residential users.
Continued success
Last year, Fox ESS’s H3 hybrid inverter and ECS system achieved a Class A rating with a performance index of 94.8% in the 10 kW residential storage system test. Additionally, earlier this year, the S&P Global Energy Residential Storage Index ranked Fox ESS #1 in market share in Europe. In 2023, the company was also included in the Forbes Unicorn list, strengthening its leading position in the industry.
Over the past three years, Fox ESS has installed more than 890,000 photovoltaic inverters and more than 1 million batteries in more than 70 countries. Looking ahead, the company remains committed to technological innovation, striving to provide high-performance products tailored to customer needs.
About Fox ESS
Founded in 2019 and headquartered in Wenzhou, China, Fox ESS is a domestic high-tech enterprise specializing in the R&D, production, sales and service of renewable energy electrical equipment, with a strong focus on advanced power electronics. Committed to global growth, Fox ESS has established a presence in more than 70 countries and regions, forging more than 200 partnerships that drive innovation across Asia, Europe, the Americas, Africa and Oceania. Guided by a customer-focused philosophy, we deliver high-efficiency renewable energy solutions worldwide through innovation and exceptional value.
SOURCE Fox ESS
