AlphaESS Secures Milestone Agreement for Czech Republic's Largest Stand-alone Energy Storage Project

Prague, Czech Republic, December 2025 — AlphaESS, a global leader in energy storage solutions and a BloombergNEF Tier 1 certified manufacturer for Q4 2025, has formally signed a cooperation agreement with EPC partner Eltodo a.s. to deliver a combined 320 MWh large-scale battery energy storage system (BESS) across two strategic sites in the Czech Republic: BESS Chvaletice and BESS Kladno. Once completed, the projects are set to become the largest Stand-alone energy storage installations in the country, marking a significant step forward in the Czech Republic's energy transition and grid modernization efforts.

Aster 5000 Deployed at Scale to Support National Grid Stability

Under the agreement, AlphaESS will supply 46 units of Aster 5000 for the Chvaletice site and 18 units of Aster 5000 for the Kladno site. The systems will primarily support frequency regulation and other grid ancillary services, enhancing the reliability, flexibility, and responsiveness of the regional power network.

Project Background and Application Needs

As the Czech power system undergoes rapid transformation, the demand for flexible grid regulation resources is steadily increasing. With renewable energy capacity expanding quickly and traditional balancing units being gradually phased out, the customer has chosen to deploy AlphaESS large-scale energy storage systems to provide fast frequency regulation, stabilize grid frequency, and deliver key ancillary services such as voltage support and reserve capacity. These large-scale BESS installations also strengthen regional grid resilience, mitigate fluctuations caused by solar and wind generation, and enable higher renewable energy penetration.

Driven by these core needs, the Chvaletice and Kladno energy storage projects were developed to provide essential flexibility and stability support for the Czech grid.

A Collaboration Built on Technical Expertise

To meet the demanding requirements of the Czech grid, AlphaESS is supplying the Aster 5000, a 5MWh liquid-cooled energy storage system designed for reliability, rapid deployment, and long-term grid support. The system features a fully integrated 20-foot design that combines the battery system, BMS, EMS, and fire-protection system into a single container, significantly reducing onsite installation and commissioning time while enabling fast, large-scale rollout.

The Aster 5000 is built with a comprehensive multi-layer safety architecture that ensures robust protection from the cell level to the system level. Its liquid-cooling design, advanced thermal management, and coordinated protection mechanisms deliver stable operation even under demanding grid-side conditions. To guarantee delivery quality, every unit undergoes a full factory acceptance test (FAT) before shipment, a level of rigor rarely seen in large-scale energy storage manufacturing.

In addition, the system incorporates cell-level bi-directional active balancing, enhancing operational efficiency and extending system lifetime by more than 10%. This makes the Aster 5000 ideally suited for long-duration grid applications and large commercial and industrial scenarios that require high performance and strong operational resilience.

Eltodo a.s., acting as the EPC, will oversee site development, civil engineering, and project execution. The combined expertise ensures high technical robustness, rapid delivery, and long-term operational reliability.

A Strategic Milestone for AlphaESS in Europe

With a growing portfolio across the EU region, the Chvaletice and Kladno projects reinforce AlphaESS's position as a leading global supplier of utility-scale energy storage solutions.

"These projects not only mark a major milestone for the Czech Republic, but also reflect AlphaESS's expanding role in enabling grid modernization and renewable energy integration across Europe," said Alfred, CEO of AlphaESS. "We are proud to work with Eltodo and support the country's transition toward a resilient, low-carbon energy future."

About AlphaESS

AlphaESS is a global leader in energy storage solutions, serving residential, commercial & industrial, and utility-scale applications. With advanced liquid-cooling technology, intelligent system control, and strong execution capability, AlphaESS has deployed systems in more than 100 countries.

As a BloombergNEF Tier 1 certified manufacturer, AlphaESS provides not only high-performance storage products but also professional end-to-end services, including pre-sales consulting, technical support, and localized after-sales service, ensuring long-term safety, stability, and efficiency throughout the entire project lifecycle. AlphaESS is committed to accelerating the global transition toward sustainable and intelligent energy systems.