PowerTrack Serves as the Integrated Control Foundation Enabling Market Participation at the Kölsa Site
Stem, Inc. (NYSE: STEM), a global leader in AI-enabled clean energy software and services, today announced that its PowerTrack™ Energy Management System (“EMS”) has been selected in collaboration with developer and EPC Everyray GmbH for two utility-scale battery energy storage system (“BESS”) projects in Germany: a 90 MWh installation in Kölsa and a 10 MWh installation in Elsterwerda. The projects are owned and financed by UESA Group, which is also supplying key electrical infrastructure, including the transformer station, handover station, and medium-voltage switchgear.
The Kölsa asset is co-located with an existing photovoltaic (“PV”) plant, while the Elsterwerda project is a standalone BESS installation. Together, the projects further expand Stem’s presence in the German market and reinforce PowerTrack EMS’s role as the control system for sophisticated, utility-scale storage deployments across Europe. Commercial operations are expected to commence in summer 2026.
“Our work with Everyray continues to demonstrate what’s possible when control infrastructure, optimization strategy, and engineering execution are aligned from the outset,” said Matt Tappin, President of Software at Stem. “As their portfolio grows in scale and sophistication, PowerTrack provides the operational backbone that enables consistent performance, regulatory compliance, and long-term asset value. We’re proud to support their continued expansion in the German market.”
PowerTrack EMS will serve as the primary control and management platform for the Kölsa BESS, leveraging Stem’s edge-to-cloud architecture to deliver continuous controller uptime, seamless integration, and robust grid code compliance. The system is certified under VDE-AR-N 4110, 4120, and 4130, covering the full range of medium and high voltage grid connection requirements applicable to utility-scale storage and hybrid assets in Germany. In addition to providing the core EMS platform, Stem is delivering engineering integration support to ensure seamless interoperability between the BESS, external optimization systems, and grid infrastructure.
“Delivering reliable, market-responsive storage requires tight coordination between hardware, control systems, and optimization platforms,” said Jochen Wolf, Co-Founder and Managing Director of Everyray GmbH. “Stem’s technical depth and collaborative integration approach have been instrumental in delivering a robust, grid-compliant solution.”
Everyray is deploying industry-leading solutions across the Kölsa site, including the optimization solution by Entrix, a market leader for trading flexible energy systems in Europe. The optimization solution will interface with PowerTrack EMS to execute AI-supported trading and ancillary services strategies. Stem’s vendor-neutral architecture enables asset owners to maintain flexibility in optimization strategy while ensuring secure, high-performance plant-level control.
“Battery storage plays an increasingly important role in strengthening the energy system by providing flexible capacity and reliable system support,” said Steffen Schülzchen, founder and CEO of Entrix. “Maximizing this value requires both technical excellence and sophisticated market execution. Through AI-powered optimization and 24/7 trading operations, we ensure that the Kölsa asset participates efficiently in Germany’s ancillary services and wholesale markets. Working alongside Everyray and Stem, we are combining advanced trading strategies with dependable, real-time plant control to deliver sustained performance and reliable market execution.”
The Kölsa and Elsterwerda deployments underscore Stem’s expanding role in Europe’s rapidly maturing storage market, where demand for scalable, vendor-neutral control architecture continues to grow alongside portfolio size and operational complexity.
For more information on Stem and the PowerTrack Suite, visit stem.com.
