Cube Concepts Acquires 100 MW Battery Storage System in Tušimice — Together with Powerlink, Power Cube Is Building the Industry’s Most Powerful Energy Network
Summary
Within just a few weeks, Kaarst-based Cube Concepts GmbH completed the acquisition of 100 MW of battery storage capacity (200 MWh) at the Tušimice Energy Park in the Czech Republic — one of the largest standalone BESS investments in Central Europe. The site has a contractually secured direct 400 kV connection to the Czech transmission grid operated by ČEPS, full construction permits, and, with Second Foundation, one of Europe’s leading BESS aggregators and a well-capitalised anchor investor operating within the same park.
Construction work is already underway, with commissioning scheduled for the end of 2026. At the same time, Powerlink H2 GmbH, based in Upper Austria, is joining as a strategic partner. The two companies are consolidating their collaboration under the new Power Cube platform — creating the industry’s most powerful energy network for integrated photovoltaic, storage and energy solutions.
Content
Kaarst, 1 June 2026 — Cube Concepts has completed the acquisition of the full 100 MW of battery storage capacity (200 MWh) at the Tušimice Energy Park in the Czech Republic. The 50 MW exclusivity secured in mid-March this year has been expanded to the full option volume within just a few weeks — a pace that is exceptional in the European BESS market and sets a new benchmark in a segment where comparable transactions typically take several quarters to complete. Construction work at the site is already underway, with commissioning scheduled for the end of 2026. The transaction is being legally advised by Hogan Lovells and Kinstellar.
A Site Combining Multiple Structural Advantages in a Single Asset
Tušimice is a rarity in the Central European storage market. The site has a contractually secured direct 400 kV connection to the Czech transmission grid operated by ČEPS. New high-voltage connections of this scale require lead times of seven to ten years in the Czech Republic, while ENTSO-E identifies lengthy permitting procedures as one of the key obstacles to European grid expansion. All construction permits for the 100 MW are in place, and the civil engineering and infrastructure works are already designed to allow the storage capacity to be doubled to 400 MWh — a full-scale four-hour system — without requiring another construction phase.
The project also benefits from a regulatory advantage that is often underestimated in market comparisons: under Czech law, battery storage is not classified as a final consumer, meaning that electricity used for charging is exempt from grid fees without a time limit. The comparable German provision under Section 118 of the German Energy Industry Act (EnWG) expires in 2029 and is currently under active review by the Federal Network Agency. In addition, the European Union has approved €279 million from the Modernisation Fund for the Czech Republic’s energy transition.
Tušimice is also not an isolated asset. At the same site, ČEZ operates an active 800 MW lignite-fired power plant, is currently constructing a 127 MW solar park and plans to develop Small Modular Reactors (SMRs) with a total capacity of up to 1,500 MW from the mid-2030s onwards. Tušimice is transforming from a historic lignite region into a multi-energy hub for Central Europe’s energy transition — and Power Cube’s 100 MW is positioned precisely to meet the flexibility demand arising from this architecture. Aurora Energy Research forecasts an equity return of more than 15 percent and a five-year payback period for Czech BESS assets commissioned in 2026.
Identical Commercial Basis with the Anchor Investor
Second Foundation, one of Europe’s leading algorithmic energy traders, is active as an anchor investor in the same park. Founded in Prague in 2019, the company is one of the largest participants in the European intraday electricity market. It is licensed as a balancing group and balancing reserve provider in seven European countries — including Germany — and operates internationally with offices on several continents.
Unlike traditional aggregators, Second Foundation controls the entire BESS value chain in-house: from its proprietary Sophon trading platform and AI-based asset optimisation to direct trading on spot and balancing energy markets. 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 — combining data, algorithms, hardware integration and market execution under one roof — remains exceptional in the European aggregator market and represents a decisive structural advantage over conventional service models.
In Tušimice, Second Foundation has acquired 200 MW (400 MWh) and operates these assets on an ongoing basis. Under a service agreement, Second Foundation will additionally handle the aggregation and marketing of the Power Cube units — both through ČEPS’s Czech balancing energy markets, including Frequency Containment Reserve (FCR) and automatic Frequency Restoration Reserve (aFRR±), currently the most economically attractive markets for Czech BESS assets, and through the Day-Ahead and Intraday segments of the spot market.
Both asset groups — Second Foundation’s 200 MW and Power Cube’s 100 MW — operate at the same site, on the same grid infrastructure, under the same commercial conditions and are marketed by the same operator. This alignment of the commercial basis is rare in today’s European storage market and gives Power Cube a fundamentally different economic risk profile compared with projects relying on an externally commissioned operator.
Growing Market Recognition for Cube Concepts
The Tušimice transaction comes at a time of growing structural market recognition for the Kaarst-based company. Just a few days ago, Cube Concepts secured a €60 million senior debt facility from institutional capital providers for its German PV and BESS pipeline.
With Tušimice, the company, founded in 2020, is for the first time acting simultaneously as a lead equity investor and long-term operator of its own generation and storage capacity. Both developments — the senior debt facility for the German pipeline and the acquisition of 100 MW in the Czech Republic — mark the transition from a purely service-oriented position to an integrated owner-operator role across two markets.
Powerlink as Strategic Partner and Future Co-Shareholder of Power Cube
With Powerlink H2 GmbH from Austria, the partnership gains a company with substantial EPC expertise in large-scale battery storage and a financially strong ownership structure. Powerlink is currently constructing Europe’s largest logistics battery storage system, with a capacity of 60 MWh, at the Hörsching logistics site in Upper Austria.
In addition, the company is developing further large-scale battery storage systems at locations in Austria, Romania, Bulgaria and Germany, with a total volume exceeding 1,400 MWh. Its shareholders include Werner Steinecker, former CEO of Energie AG Oberösterreich. Effective 1 July 2026, the company will change its name to Powerlink GmbH.
Under the joint Power Cube platform, Powerlink will become a strategic partner and future co-shareholder. Power Cube serves as the platform for the development, ownership and long-term operation of the partners’ joint asset pipeline.
“The secured 400 kV connection, the advanced permitting status and the quality of the partners already involved make this combination exceptional anywhere in Europe. We wanted to be part of it. From the outset, Powerlink has focused on large-scale battery storage systems for demanding industrial applications,” says Manuel Pfeil, CTO of Powerlink H2 GmbH. “With Cube Concepts, we are gaining a partner with access to the commercial and industrial market and expertise in the integrated photovoltaic and storage business. Power Cube is the platform that allows us to scale both at a level that is still rarely seen in the European storage market.”
“We did not choose the Czech Republic because it was the easier route — we chose it because the combination of a secured grid connection, a well-capitalised anchor investor in the same park and a stable legal framework without a regulatory expiry date cannot currently be replicated in Germany,” says Jochen Schäfer of Cube Concepts.
“With Powerlink, we are gaining a partner that brings industrial depth and strong equity backing. Together, we are building the industry’s most powerful energy network — combining EPC expertise, access to commercial and industrial customers, and a portfolio that can be scaled across national borders. Tušimice is the first transaction under this structure. It will not be the last.”
