Stem’s PowerTrack EMS Enables Hybridization of Two Operating Utility-Scale Solar Plants in Hungary
Five-year agreement extends Stem’s existing plant power control foundation as Solarmarkt Group adds 160 MWh of battery storage across two major sites in Hungary
HOUSTON–(BUSINESS WIRE)–
Stem, Inc. (NYSE: STEM), a global leader in AI-enabled clean energy software and services, today announced that Solarmarkt Group, together with engineering, procurement, and construction (EPC) partner Pannonwatt Energetikai Megoldások Zrt. (Pannonwatt), has selected Stem’s PowerTrack™ Energy Management System (EMS) as the integrated energy management, power plant control (PPC), and SCADA platform for the hybridization of two operating utility-scale solar plants in Hungary, establishing one of the most advanced digital renewable energy hubs in Central and Eastern Europe.
The projects will add a 40 MW / 80 MWh battery energy storage system to each of Solarmarkt Group’s existing 60 MWp solar facilities: one in Szihalom and one in Hódmezővásárhely. Once completed, each site will operate as a fully integrated hybrid renewable asset. Commercial operation of the fully hybridized assets is expected by September 2026.
Stem previously supplied the power plant control (PPC) capabilities for the solar facilities in 2025 and 2026 using a hybrid-ready PowerTrack architecture. Under the new five-year agreement, the same software and controls foundation will expand across the battery systems at each site, enabling solar generation, storage, grid interconnection, and market dispatch to operate through a single integrated solution.
The hybridization of the Szihalom and Hódmezővásárhely plants also strengthens the physical renewable-energy foundation of Solarmarkt Group’s Green Cloud Platform. The platform connects renewable generation with corporate energy consumers, supporting their decarbonization objectives through traceable, auditable physical green-energy solutions. By combining solar generation with battery storage and advanced controls, the projects can help make renewable electricity more controllable, more flexible and fully prepared for cross-border, value-stacking opportunities as Central and Eastern European energy markets become increasingly interconnected.
“This project demonstrates how operating solar plants can evolve into hybrid assets without replacing the existing controls foundation,” said Matt Tappin, President of Software at Stem. “Because PowerTrack EMS was designed with hybridization in mind, we can extend the platform across the battery systems while preserving the controls and operating experience already in place. This gives owners a more efficient path to adding storage and a clearer view of both technical and commercial performance.”
At each facility, PowerTrack EMS will coordinate solar generation, battery dispatch, grid constraints, and market dispatch instructions while maintaining compliance with E.ON distribution-system requirements. The initial commercial strategy will focus on participation in Hungary’s automatic Frequency Restoration Reserve (aFRR) market, with the platform designed to support future Frequency Containment Reserve (FCR) services and cross-border, value-stacking opportunities as Central and Eastern European energy markets become increasingly interconnected.
“For us, this project is about creating a platform that allows us to continuously understand and improve the technical and commercial performance of our assets,” said Miklos Mormer, Chief Technology Officer, Solarmarkt Group. “PowerTrack EMS provides transparency into the performance and economics of both the solar and battery systems at each site, while allowing them to operate as coordinated hybrid assets. It also gives us a foundation that can evolve as Hungary’s ancillary-services market develops.”
Executing a project of this scale and complexity in a rapidly evolving market requires deep localized engineering excellence,” said Róbert Vőneki, Chief Executive Officer at Pannonwatt. “Pannonwatt’s advanced grid-integration capability, combined with Stem’s utility-scale software, will help mitigate execution risks. We are building infrastructure that is setting the technical benchmark for how existing solar assets across Europe can adapt to the future grid.
The projects reflect a broader shift across European renewable-energy markets as owners add battery storage to operating solar facilities to increase flexibility, reduce curtailment, and create new sources of value. The collaboration among Solarmarkt Group, Pannonwatt, and Stem provides a model for converting existing solar plants into integrated hybrid renewable assets while retaining established plant infrastructure and controls.
For more information on Stem and the PowerTrack Suite, visit stem.com.
About Stem
Stem (NYSE: STEM) is a global leader reimagining technology to support the energy transition. We turn complexity into clarity and potential into performance.
Stem helps asset owners, operators, and energy stakeholders unlock the full value of their portfolios by enabling the intelligent development, deployment, and operation of clean energy assets. Stem’s integrated software suite, PowerTrackTM, is the industry-standard and best-in-class platform for asset monitoring and optimization and is backed by expert professional and managed services, all delivered under one roof. Designed to address complex energy challenges seamlessly, our technology transforms raw data into clear, actionable insights, providing the visibility and intelligence needed to drive performance. With projects across 55 countries, customers have trusted Stem for nearly 20 years to maximize the value of their clean energy investments.
Driven by human and artificial intelligence, Stem is unlocking energy intelligence. Learn more at stem.com.
About Solarmarkt Group
Solarmarkt Group is a Hungary-based renewable energy company focused on the development, operation, and optimization of utility-scale clean energy assets. Through its Green Cloud Platform, the company connects renewable energy generation with corporate energy consumers, helping customers advance decarbonization goals through innovative energy solutions. As a strategic partner of E.ON, Solarmarkt Group develops and manages renewable energy projects that support the transition to a more flexible, low-carbon electricity system across Central and Eastern Europe.
About Pannonwatt Energetikai Megoldások Zrt
Pannonwatt Energetikai Megoldások Zrt. (Pannonwatt) is a Hungary-based engineering, procurement, and construction (EPC) company specializing in utility-scale renewable energy and energy storage projects. As a strategic partner of E.ON, Pannonwatt delivers end-to-end solutions spanning project development, engineering, construction, commissioning, and energy optimization. The company supports customers across Hungary with integrated solar, battery energy storage, and hybrid energy systems designed to improve grid reliability, operational performance, and long-term asset value.
Forward-Looking Statements
This press release, as well as other statements we make, contains “forward-looking statements” within the meaning of the federal securities laws, which include any statements that are not historical facts. Such statements often contain words such as “expect,” “may,” “can,” “believe,” “predict,” “plan,” “potential,” “projected,” “projections,” “forecast,” “estimate,” “intend,” “anticipate,” “ambition,” “goal,” “target,” “think,” “should,” “could,” “would,” “will,” “hope,” “see,” “likely,” and other similar words. Forward-looking statements address matters that are, to varying degrees, uncertain, such as statements about our business strategies and those of our customers; our ability to retain or upgrade current customers, and our ability to further penetrate the European market or expand into new markets. Such forward-looking statements are subject to risks, uncertainties, and other factors that could cause actual results or outcomes to differ materially from those expressed or implied by such forward-looking statements, including but not limited to our ability to achieve the expected benefits from our expansion into new markets, as well as our operational and strategic initiatives; including from our cost reduction and restructuring efforts; our inability to successfully execute on our strategy; the effects of the One Big Beautiful Bill on our business and that of our customers; disruptions in sales, production, service or other business activities; general macroeconomic and business conditions in key regions of the world, including inflationary pressures, general economic slowdown or a recession, high interest rates, changes in monetary policy, changes in trade policies, including tariffs or other trade restrictions or the threat of such actions, and instability in financial institutions; the direct and indirect effects of widespread health emergencies on our workforce, operations, financial results and cash flows; geopolitical instability, such as the armed conflicts between Russia and Ukraine and in the Gaza Strip and nearby areas; the results of operations and financial condition of our customers; pricing pressures; severe weather and seasonal factors; our inability to continue to grow and manage our growth effectively; our inability to attract and retain qualified employees and key personnel; our inability to comply with, and the effect on our business of, evolving legal standards and regulations, including those concerning data protection, consumer privacy, sustainability, and evolving labor standards; risks relating to the development and performance of our software-enabled services; our inability to retain or upgrade current customers, further penetrate existing markets or expand into new markets; the risk that our business, financial condition and results of operations may be adversely affected by other political, economic, business and competitive factors; and other risks and uncertainties discussed in this release and in our most recent Forms 10-K, 10-Q and 8-K filed with or furnished to the SEC. If one or more of these or other risks or uncertainties materialize (or the consequences of any such development changes), or should our underlying assumptions prove incorrect, our actual results or outcomes, or the timing of these results or outcomes, may vary materially from those reflected in our forward-looking statements. Forward-looking statements and other statements in this release regarding our environmental, social, and other sustainability plans and goals are not an indication that these statements are necessarily material to the Company, investors, or other stakeholders, or required to be disclosed in our lings under U.S. securities laws or any other laws or requirements applicable to the Company. In addition, historical, current, and forward-looking environmental, social, and sustainability-related statements may be based on standards for measuring progress that are still developing, internal controls and processes that continue to evolve, and assumptions that are subject to change in the future. Forward-looking statements in this press release are made as of the date of this release, and the Company disclaims any intention or obligation to update publicly or revise such forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by law.
View source version on businesswire.com: https://www.businesswire.com/news/home/20260812734966/en/
For News Media:
Stem Investor Contacts
Erin Reed, Stem
Marc Silverberg, ICR
[email protected]
Stem Media Contact
Tatjana Legans, Stem
[email protected]
KEYWORDS: Texas Europe United States North America Hungary
INDUSTRY KEYWORDS: Alternative Energy Energy Technology Software Utilities
MEDIA:
| Logo |
 |