Together with Powerlink: the industry's most powerful network
Within a few weeks, we acquired 100 MW of battery storage capacity (200 MWh) in the Czech energy park of Tušimice. This is one of the largest standalone BESS investments in Central Europe. The site has a contractually secured 400 kV direct connection to the Czech transmission network ČEPS. All building permits are in place. Second Foundation is represented in the park as one of the leading European BESS aggregators as a capital-rich anchor investor. Construction has begun, with commissioning scheduled for the end of 2026. At the same time, a strategic partner is joining in the form of Second Foundation. Both companies are pooling their collaboration under the new platform Power Cube. This creates the most powerful power network in the industry for integrated photovoltaic, storage, and energy solutions.
In mid-March of this year, we secured a 50 MW exclusivity. Within a few weeks, this became the full option length. This pace is an exception in the European BESS market. Comparable transactions in this segment usually take quarters – with this we set new standards. Construction work at the site has begun. Commissioning is scheduled for the end of 2026. Legal support for the transaction is provided by Hogan Lovells and Kinstellar.
A location that combines multiple structural advantages in a single asset
Tušimice is a rarity in the Central European storage market. The site has a contractually secured 400 kV direct connection to the Czech transmission network ČEPS. New high-voltage connections of this magnitude require seven to ten years of lead time in the Czech Republic. ENTSO-E lists lengthy approval procedures as one of the key obstacles to European network expansion. All building permits for the 100 MW are in place. The underground and infrastructure work has already been designed for a later expansion. This allows the capacity to be doubled without a new construction phase to 400 MWh – a fully-fledged 4-hour system.
In addition, there is a regulatory advantage that is often underestimated in the market comparison. In the Czech Republic, a battery storage system is not considered a final consumer by law. Charging current is exempt from network charges for an indefinite period. The German comparison regulation under § 118 of the EnWG expires in 2029 and is currently being actively reviewed by the Federal Network Agency. The European Union has additionally allocated 279 million euros from the Modernization Fund for Energy Transformation for the Czech Republic.
Tušimice is also not an isolated asset. At the same site, ČEZ operates an active 800 MW brown coal power plant and is currently constructing a 127 MW solar park. Starting in the mid-2030s, ČEZ plans to build small modular reactors (SMR) with a total capacity of up to 1,500 MW there. Thus, Tušimice is transforming from a historical brown coal region into a multi-energy hub of the Central European energy transition. The 100 MW Power Cube is precisely tailored to the flexibility demand generated by this architecture. Aurora Energy Research forecasts a return on equity of over 15 percent for Czech BESS assets in 2026 and a payback in five years.
Identity of the business basis with our anchor investor
In the same park, Second Foundation, one of Europe's leading algorithmic energy traders, is active as an anchor investor. Founded in Prague in 2019, the company is one of the largest players in the European intraday electricity market, is licensed as a balancing group and grid reserve provider in seven European countries—including Germany—and has an international presence with offices on multiple continents. Unlike traditional aggregators, Second Foundation controls the entire BESS value chain in-house: from its proprietary trading platform and AI-supported asset optimization to integrated BESS solutions via its stake in BESS hardware manufacturer GAZ. Second Foundation invests its own capital in its own battery storage systems and operates them as an independent power producer in several European countries. This vertical integration—data, algorithms, hardware integration, and market execution under one roof—is the exception in today's European aggregator market and the decisive structural advantage over traditional service models.
In Tušimice, Second Foundation has acquired 200 MW (400 MWh). On the basis of a service agreement, Second Foundation additionally assumes the aggregation and marketing of the Power Cube units — both via the Czech balancing energy markets of ČEPS — primary control reserve FCR and secondary control reserve aFRR±, which are currently the most economically lucrative markets for Czech BESS assets — and via the day-ahead and intraday spot market segments. Both groups of systems — the 200 MW Second Foundation and the 100 MW Power Cube — operate at the same location, on the same grid infrastructure, under the same commercial conditions, marketed by the same actor. This is an identity of the business foundation that is rare in today's European storage market and fundamentally alters the economic risk profile of Power Cube compared to that of a project with an externally contracted operator.
“As soon as the balancing energy market reaches its capacity limit, the focus of optimization shifts to the wholesale electricity market — and that is precisely where our experience in algorithmic trading becomes the decisive advantage.”
Tomáš Wiedermann, Chief Investment Officer (CIO), Second Foundation
Growing market recognition for Cube Concepts
The Tušimice transaction falls into a phase of structural market recognition for our company. Just a few days ago, we secured a senior debt facility of 60 million euros from institutional capital providers for our German PV and BESS pipeline. With Tušimice, we are acting for the first time simultaneously as an equity-holding investor and long-term operator of our own generation and storage capacities. Both events—the senior debt facility for the German pipeline and the 100 MW acquisition in the Czech Republic—mark our transition from a pure service perspective to an integrated owner and operator position in two markets.
Powerlink as a strategic partner and future co-shareholder of Power Cube
With Powerlink H2 GmbH from Austria, a partner is joining that itself possesses significant EPC depth in the field of large-scale battery energy storage systems and a well-capitalized ownership structure. Powerlink is currently constructing Europe's largest logistics battery storage system, with 60 MWh, at the logistics hub in Hörsching, Upper Austria. In addition, the company is realizing further large-scale battery storage projects at locations in Austria, Romania, Bulgaria, and Germany with a total volume of over 1,400 MWh. Its owners include Werner Steinecker, the former CEO of Energie AG Oberösterreich. Effective July 1, 2026, the company will change its name to Powerlink GmbH. Operating under the joint platform Power Cube, Powerlink will become our strategic partner and future co-shareholder — Power Cube is the platform for the development, ownership, and long-term operation of our shared asset pipeline.
“The secured 400 kV grid connection, the advanced state of the permitting process, and the quality of the partners already acquired are exceptional in this combination throughout Europe. We wanted to be part of it. Since its inception, Powerlink has relied on large-scale battery storage for demanding industrial applications. With Cube Concepts, we are gaining a partner that has market access in the commercial and industrial segment and masters the integrated business of photovoltaics and storage. Power Cube is the platform to scale both in a league that is rarely found in the European storage market today.”
Manuel Pfeil, CTO of Powerlink H2 GmbH
We did not choose the Czech Republic because it was the easier path — but because the combination of a secured grid connection, a well-capitalized anchor in the same park, and a stable legal framework without a regulatory expiration date cannot be replicated in Germany today. With Powerlink, we are gaining a partner that brings industrial depth and strong equity substance. From this setup, we are forming the industry's most powerful power network — EPC depth, commercial-industrial customer access, and a cross-border scalable portfolio bundled in a single entity. Tušimice is the first transaction under this structure. It will not be the last.
Jochen Schäfer, Chief Investment Officer, Cube Concepts
With Tušimice, we are launching a pipeline designed to scale beyond the Czech border into Central Europe. What unites us and Powerlink under Power Cube is not a single transaction, but a platform logic of development, ownership, and operation of integrated photovoltaic, storage, and energy solutions — combined into the industry's most potent power network.
About Powerlink H2 GmbH
Powerlink H2 GmbH, based in Austria, builds large-scale battery storage systems and hydrogen plants for industrial applications. Its currently most visible project is Europe's largest logistics battery storage system with 60 MWh at the Hörsching site. As of July 1, 2026, the company will change its name to Powerlink GmbH.
Frequently Asked Questions
What is Power Cube?
Power Cube is our joint platform with Powerlink H2 GmbH for the development, ownership, and long-term operation of integrated photovoltaic, storage, and energy solutions. The first transaction under Power Cube is the acquisition of a 100 MW battery storage system in Tušimice, Czechia.
Where is Tušimice located?
Tušimice is located in northwestern Czechia, about 90 kilometers northwest of Prague, in the Chomutov District. The energy park is an established hub for the Czech power supply and is transforming from a historical brown coal region into a multi-energy location featuring a battery storage system, a solar park, and prospectively small modular reactors.
What does a 100 MW (200 MWh) battery storage system mean?
100 MW refers to the power output—meaning how much electricity the storage system can absorb or release at the same time. 200 MWh refers to the storage capacity—meaning the total amount of energy that can be stored. When fully charged, the facility can thus deliver 100 MW for two hours. The civil engineering and infrastructure work in Tušimice are already dimensioned so that the capacity can later be doubled to 400 MWh (four hours).
When does Tušimice start operating?
The commissioning of the 100 MW Power Cube in Tušimice is scheduled for the end of 2026. Construction work has already begun.
Who is Second Foundation?
Second Foundation is one of Europe's leading algorithmic energy traders. Founded in Prague in 2019, the company is licensed as a balancing group and grid reserve provider in seven European countries—including Germany—and operates its own battery storage systems as an Independent Power Producer in several European countries. In the Tušimice energy park, Second Foundation holds 200 MW (400 MWh) and additionally handles the commercialization of the Power Cube units.
What distinguishes the Czech from the German BESS market?
In the Czech Republic, battery storage is legally not considered a final consumer, and charging electricity is indefinitely exempt from grid fees. The comparable German regulation under § 118 of the Energy Industry Act (EnWG) expires in 2029 and is under active revision. In addition, the European Union has approved 279 million euros from the Modernisation Fund for the Czech Republic's energy transformation. Aurora Energy Research forecasts a return on equity of over 15 percent for Czech BESS assets in 2026.
How can you find out more?
For press inquiries and further information, contact Géraldine Winter, Chief Marketing Officer, at geraldine.winter@cubeconcepts.de.