Second Foundation Builds Three Large-Scale Battery Storage Systems Totaling 307 MW in the Czech Republic – with European Technology and Proprietary Control Software
Prague – Rising electricity price volatility and the growing share of renewable energy are driving demand for large-scale flexibility assets in the Czech Republic as well. With an investment volume of over 160 million euros across three large-scale battery storage systems, Czech energy trading and technology company Second Foundation is now making a bold statement.
Vraňany, Stonava, Tušimice: Three Projects Strengthen the Czech Transmission Grid
Second Foundation is developing three two-hour battery storage projects together with partners, with commissioning targeted by end of 2026. In Vraňany (Mělník district), a 20 MW/40 MWh system is being built, sharing a grid connection with the neighboring 33 MW Vepřek solar power plant. In Stonava (Moravian-Silesian Region), an 87 MW/180 MWh storage system will be constructed, which upon commissioning in late summer 2026 will temporarily be the most powerful standalone battery storage facility in the country. The flagship project Tušimice, at 200 MW/400 MWh, will be connected directly to grid operator ČEPS's 400 kV transmission network – via the first privately operated substation in the Czech Republic. An expansion to 210 MW/420 MWh is planned.
Vojtěch Kačena, founder of Second Foundation: "We build batteries. In an environment of growing electricity price volatility, batteries enable an efficient integration of renewables into the grid. For consumers this means more stable prices over the long term, and for Europe the opportunity to continue reducing the share of fossil fuels in the energy mix."
European Supply Chain: GAZ Energy from Bohumín, with Roots in the Geräte- und Akkumulatorenwerk Zwickau
All three projects rely on a consistently European technology chain. The battery systems are supplied by GAZ Energy, a Czech manufacturer with a production facility in Bohumín and roots in the German Geräte- und Akkumulatorenwerk Zwickau. The company currently produces systems for European projects with a total capacity of 1,500 MWh. The energy and battery management systems (EMS/BMS) were developed in-house by Second Foundation – ensuring full data control and cybersecurity within European infrastructure. David Vodička, board member of GAZ Energy: "We place the highest emphasis on safety in compliance with all European standards and on optimization for integration with leading trading platforms, enabling asset owners to maximize their return on investment."
Algorithmic Trading as a Revenue Driver: 340,000 Euros per MW in 2025
Optimization of all three projects is handled by Nano Energies, a recently acquired subsidiary with 16 years of market experience. Second Foundation currently manages over 110 MW of battery storage across several European markets as well as Japan through automated trading with more than 100,000 transactions per day. Battery storage assets in the portfolio generated average annual revenues of 340,000 euros per MW in 2025. CIO Tomáš Wiedermann: "All three projects are proceeding on schedule and heading for commissioning by the end of 2026. Together, 307 MW of new capacity will significantly strengthen the Czech transmission system."
Jan Fousek, Managing Director of industry association AKU-BAT CZ: "The Czech battery storage market is finally moving from project proposals to actual construction. Professional trading of large-scale storage assets is what separates successful projects from the rest. The banks financing these projects know this — which is why they require an experienced flexibility aggregator."
Source: IWR Online, 03 Jun 2026
