12/02/2025

Best PV2Bat Efficiency at 98.2% – KOSTAL Impresses in Storage Test for the Eighth Consecutive Time

KOSTAL Inverter PLENTICORE G3 Excels in the 2025 Energy Storage Inspection.

Top Efficiency Class and Outstanding Efficiency Ratings

The results of the 2025 Energy Storage Inspection by the Berlin University of Applied Sciences (HTW Berlin) confirm: KOSTAL sets new standards in PV storage system efficiency with its latest PLENTICORE G3 inverter.

Thanks to technological innovations, KOSTAL has secured a place among the top five most efficient systems and has been classified in the highest efficiency class, A. A particular highlight is the exceptional efficiency in the PV-to-battery (PV2Bat) charging path, achieving an impressive 98.2%—the best value among all tested systems.

German Solar Technology at the Highest Level

PLENTICORE G3 with BYD battery in SPI 2025

PLENTICORE plus with BYD battery in SPI 2025

PLENTICORE plus with Dyness battery in SPI 2025

PLENTICORE plus with Pylontech battery in SPI 2025

The continuous development of KOSTAL inverters is paying off: the PLENTICORE G3 generation delivers outstanding results, emphasizing advancements in efficiency and system optimization.

The PLENTICORE plus had already achieved the crucial and remarkable energy efficiency class A last year, confirming the consistently high quality and efficiency of KOSTAL products.

KOSTAL has now participated in the Energy Storage Inspection for the eighth time, consistently ranking among the top performers. This continuity highlights the company’s high level of innovation and its commitment to continuous technological improvement.

Why KOSTAL? High Compatibility with Storage Partners

Another key advantage—for both end customers and installers—is the broad range of compatible storage partners.

This allows flexible selection based on the desired storage capacity or preferred price range.

Additionally, the variety of installation options provides installers with maximum flexibility during commissioning.

KOSTAL Inverters: Future-Ready – Independently Tested and Confirmed

With outstanding energy efficiency, minimized conversion losses, and optimized control technology, KOSTAL offers a solution that guarantees maximum cost-effectiveness for PV storage systems. The results of HTW Berlin’s 2025 Storage Inspection confirm KOSTAL’s leading position in sustainable solar technology.

“Our focus is on continuously improving the efficiency of PV storage systems. The fact that we have reached the top tier with the PLENTICORE G3 and achieved the best PV2Bat efficiency of all tested systems at 98.2% shows that we are on the right path,” says Andreas Forck, Senior Manager R&D at KOSTAL.

With this success, KOSTAL sets a strong benchmark for the future of photovoltaic storage—powerful, efficient, and pioneering for a sustainable energy supply.

About the System Performance Index (SPI) of HTW Berlin

The System Performance Index (SPI) from the Berlin University of Applied Sciences (HTW Berlin) is a recognized evaluation method for assessing the efficiency of PV storage systems. The SPI considers all energy flows and evaluates systems based on cost-effectiveness and efficiency. Through practical tests under real-world conditions, it provides a reliable comparison tool for both end customers and industry professionals.