Bucharest, Romania, November 13th — HiTHIUM, a global leader in integrated, full-scenario energy storage solutions, is partnering with Romanian renewable energy contractor Simtel on utility-scale storage. HiTHIUM will supply DC-side battery energy storage systems (BESS) for a new hybrid clean energy park in Sebeș, central Romania, developed by Windin Capital and El-Mor Group through the project company HEPA Energy The plant includes 67.46MWp of photovoltaic power capacity, co-located with 181.25MWh of energy storage, making it one of the largest hybrid projects in Romania.
Together with HiTHIUM, Simtel will cover the operational and maintenance services (O&M) of its energy storage systems. As part of its integrated energy storage solution offering, HiTHIUM ensures reliable and efficient system performance throughout the project lifecycle. To ensure the rapid supply of spare parts, the manufacturer also maintains warehouses across the continent, supported by third-party logistics partnerships.
HiTHIUM system design enhances PV compatibility and environmental compliance
The Sebeș park will deploy 29 of HiTHIUM's ∞Power 6.25MWh BESS systems, delivering an integrated long-duration energy storage solution designed to maximize the value of renewable energy assets. With a lifespan specifically engineered to align with that of solar plants, the systems enable seamless integration between PV generation and energy storage, supporting long-term asset performance and operational efficiency. HiTHIUM also designed the container for optimal technical compatibility with PV configuration, while enhancing land utilization and reducing long-term OPEX. The container also minimizes noise pollution, operating at just 65dB, while helping asset owners meet environmental regulations through the use of a new eco-friendly refrigerant and 100% recyclable components.
"Partnering with Simtel on such a significant, large-scale plant marks a meaningful step forward for us in Eastern Europe, especially following on our new ranking – for the first half of 2026 – as a top-two supplier globally. With Simtel, we share a strong commitment to supporting Romania's clean energy transition and its next phase, hybridization," said Kelson Li, Vice President of HiTHIUM Europe. "Due to the super compatible design, our 6.25MWh BESS can be deployed seamlessly with photovoltaics in hybrid contexts, so this is the perfect way to introduce this product to the Romanian market. The Sebeș installation, built by Simtel for HEPA Energy, will set operational and financial benchmarks for combining clean power generation with energy storage, demonstrating how hybrid plants like this can deliver bankable, grid-friendly electricity."
Scale of Sebeș project consolidates Simtel's position as renewables engineering leader
Simtel itself will deliver O&M services for the solar park, adding Sebeș to its existing 450MWp of European maintenance agreements and together with HiTHIUM will ensure the O&M services of BESS. As a leading EPC in the region, Simtel has also built over 500MWp of solar plants, while as a developer-operator, the company owns and operates more than 150MWp of PV capacity.
The renewable power generated and stored by the plant will be delivered to the national grid, helping to strengthen energy security and stabilize supply, while also enabling the broader transformation of the grid toward greater sustainability.
Asset reliability and long-term performance boosted by HiTHIUM safety engineering
The integrated 6.25MWh long-duration energy storage system's intrinsic safety features may be the container's most outstanding feature. A dramatic open-door test in early 2026, conducted independently by U.S. safety certification specialist UL Solutions, validated the product's safety. The doors of the container were kept open during the entire test, to increase oxygen supply and provide maximal opportunity for thermal spread. Adjacent containers, with their systems also 100% charged, were placed side-by-side and back-to-back. Even relying only on intrinsic safety design, with the product's active fire suppression systems disabled, the container being tested remained structurally intact and its neighbours were unaffected.
About HiTHIUM
Founded in 2019, HiTHIUM is a leading global company in renewable energy technology, committed to delivering energy storage solutions centered on advanced energy storage battery and system technologies. With robust research, production, sales, and service capabilities worldwide, HiTHIUM is the only energy storage-focused company to achieve GWh-scale global shipments of lithium-ion ESS batteries. Capping off a remarkable year, HiTHIUM has secured the TOP 2 position worldwide in terms of energy storage batteries shipment in the first half of 2026, according to authoritative institutions including InfoLink Consulting, Shanghai Metals Market (SMM), ICCSINO Data, and Zhuiguang New Energy (NECi). Through HiTHIUM Europe, the company now delivers to over 18 European countries, including the world's first 6.25MWh BESS project. As a global leader in integrated, full-scenario energy storage solutions, HiTHIUM combines innovative technologies, advanced products, and lifecycle services to address diverse energy storage needs worldwide, from renewable integration and grid-scale applications to commercial and industrial scenarios.
About Simtel
[Simtel is a technology, engineering, and innovation group with Romanian roots, international presence, and a global vision. The group provides companies and organizations with comprehensive solutions and integrated ecosystems, covering the entire process from consultancy, authorization, design, engineering, and construction to maintenance, operation, measurement, control, and energy supply. Simtel’s 360° expertise spans photovoltaic power plants, telecommunications, energy storage systems, as well as software platform development and robotic process automation, aiming to optimize resources and enhance efficiency. Simtel Team is listed on the Main Market of the Bucharest Stock Exchange under the ticker symbol SMTL.]
About El-Mor Group and Windin Capital
El-Mor Group and Windin' Capital are Israeli companies with complementary expertise in the energy sector. El-Mor is a publicly traded engineering and infrastructure group specializing in large-scale EPC projects, including power generation, renewable energy, battery energy storage systems (BESS), high-voltage substations, and electrical infrastructure.
Windin’ Capital is a private equity fund and renewable energy investment and development platform focused on OECD markets. The fund originates, develops, finances, invests in, and executes utility-scale renewable energy and energy storage projects across international markets. Its team brings extensive experience across the full project lifecycle, with expertise in wind, solar, and battery storage projects.
Together, the companies bring a powerful combination of financial strength, development expertise, and proven engineering and execution capabilities.
