Second Foundation is Developing 307 MW of Battery Storage in the Czech Republic. Ancillary Services Market Nears Capacity .
BESS Tušimice site
PRAGUE (22 April 2026)
Second Foundation, a Czech technology and energy trading company, is developing three battery energy storage systems (BESS) with a combined installed capacity of 307 MW. The projects represent the largest private investment in flexible energy assets in the Czech Republic to date, exceeding CZK 4 billion (approximately EUR 160 million). Projects are being developed in partnership with technology partner GAZ Energy and partners ADI, Decci, RSJ Investments, and the Ungelt Group. Flexibility optimization is provided in-house, thanks to a recent acquisition of Nano Energies.
“We do what we said we would do: 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. Even though our primary markets are abroad, we are a Czech company and we want to invest in BESS in the Czech Republic.”
— Vojtěch Kačena, Founder, Second Foundation
Projects Targeted for Commissioning by End of 2026
BESS Vraňany | 20 MW / 40 MWh
The facility is located adjacent to Decci’s Energy Nest hybrid power complex in the Mělník district. It shares a grid connection with the nearby 33 MW Vepřek photovoltaic plant, leveraging shared infrastructure. Second Foundation holds an ownership stake in the project alongside the Decci Group
“Two years ago, we commissioned what was then the largest battery storage facility in the Czech Republic as part of Energy Nest. The technical and commercial flexibility experience we gained is now being applied to BESS Vraňany. We develop our assets close to existing infrastructure and interconnect them into a single decentralizedenergy complex.”
— Darina Merdassi, CEO, Decci Group
BESS Stonava
BESS Stonava | 87 MW / 180 MWh
Located in an industrial zone in the Moravian-Silesian Region with a direct connection to the distribution grid, BESS Stonava is scheduled for commissioning in late summer 2026. At that point it will be the largest stand-alone battery storage facility in the Czech Republic — both by installed power and energy capacity. Second Foundation is investing alongside its partners from RSJ Investments and the Ungelt Group.
BESS Tušimice | 200 MW / 400 MWh
The largest of the three projects (once completed, the power and capacity will be increased to 210 MW/420 MWh) will be connected directly to the ČEPS transmission system via the first privately owned substation in the Czech Republic — bypassing the distribution network entirely. Once operational, it will be the largest battery energy storage facility in the country.
The substation and project were developed by Active Development Investment (ADI), a Czech developer with extensive experience in energy and renewables.
“This is currently one of the largest energy projects in the Czech Republic and will play a major role in strengthening the national power system. We are proud to be part of it. It builds on our earlier experience as one of the first companies in the country to prepare and deliver large-scale wind and photovoltaic plants.”
— Martin Hodan, Board Member, Active Development Investment (ADI)
Together with its partners from the Ungelt Group, Second Foundation holds half of the Tušimice project capacity. The remaining half is held by Czech Energy Parks together with other investors.
Optimization: A Core Capability of the Second Foundation Group
BESS Vraňany
Second Foundation brings in-house optimization capability to its projects through Nano Energies, a flexibility optimization leader with 16 years of operational track record. Second Foundation group currently manages over 110 MW of BESS across the Czech Republic, Germany, Belgium, Japan, and other markets — through fully automated trading that executes more than 100,000 trades per day across ancillary service markets (FCR, aFRR, mFRR), the day-ahead market, and the intraday market. Battery storage assets in the Second Foundation group portfolio generated average annual revenue of EUR 340,000 per MW in 2025.“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 — the batteries will provide the full spectrum of ancillary services. The Tušimice project is also connected directly to the ČEPS transmission system via its own 400 kV connection point, which is exceptional for a private project in the Czech Republic. As the ancillary services market gradually reaches capacity, the focus of optimization will shift toward the wholesale power market — and that is precisely where our experience in algorithmic trading becomes a decisive advantage.”
Tomáš Wiedermann, Chief Investment Officer (CIO), Second Foundation
Technology: GAZ Energy and European Cybersecurity
The BESS technology is supplied by GAZ Energy, a Czech manufacturer of industrial battery storage systems with a manufacturing facility in Bohumín and a strategic partner of Second Foundation.
GAZ Energy is currently producing battery systems for European projects with a combined capacity of 1,500 MWh, many of which are developed in partnership with Second Foundation.
GAZ Energy systems are equipped with proprietary energy management systems (EMS) and battery management systems (BMS) software developed directly by Second Foundation, ensuring full control over data and operations within the European infrastructure.
“Our battery systems are built on premium hardware components and state-of-the-art technology, ensuring reliable grid connection and maximum equipment availability. 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.”
— David Vodička, Board Member, GAZ Energy
The Czech Ancillary Services Market
The total capacity of the Czech ancillary services market is approximately 1 GW. The segments most relevant to battery storage are aFRR, with approximately 300 MW of capacity, and FCR, with approximately 70 MW. Second Foundation’s projects, together with those being prepared by other major players, will effectively fill this available space. For the Czech power system, this represents a fundamental shift: greater transmission system resilience, expanded capacity for connecting renewable energy sources, and real readiness for the next phase of the energy transition.
“The Czech projects are highly attractive for our portfolio — they combine a stable regulatory environment, high-quality infrastructure, and growing demand for flexibility. At the same time, it must be said that these projects will effectively bring the Czech ancillary services market for BESS to capacity. For us, this likely marks the conclusion of our battery storage investments in the Czech Republic — we expect further growth in other European markets, where we have a pipeline of projects totaling several GW.”
— Tomáš Wiedermann, Chief Investment Officer (CIO), Second Foundation
Jan Fousek, Executive Director of AKU-BAT CZ (Czech Association for Energy Storage), also underlines the importance of professional management of modern energy assets:
“The Czech battery storage market is finally moving from project proposals to actual construction — and that is a fundamental shift. The market is maturing, and with it come growing demands for professional management and optimization of storage assets. 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 with a proven track record. Projects that meet this standard are advancing the entire Czech energy market.”
— Jan Fousek, Executive Director, AKU-BAT CZ (Czech Association for Energy Storage)