Green Flexibility, which describes itself as a long-term investor, developer and operator of large-scale BESS projects in Germany, was founded in 2023 by a team largely composed of former employees of residential BESS provider Sonnen.
This includes Sonnen co-founder and CEO Christoph Ostermann, who left the company following its acquisition by Shell. Ostermann spoke with ESN Premium in early 2025 about Green Flexibility’s strategy and said that only those with deep experience would succeed in Germany’s rapidly growing BESS market.
The newly acquired portfolio is participating in Germany’s current round of maturity assessments for high-voltage grid connections. This new process replaces a ‘first-come, first-served’ approach to the grid connection queue and has been largely welcomed by developers.
Jinko ESS signs 400MWh Eastern Europe supply deal
Jinko ESS, the energy storage system integrator subsidiary of major Chinese solar PV manufacturer Jinko Solar, has signed a supply agreement with developer Taliva Energy.
Taliva Energy is focused on end-to-end renewable energy project solutions in Romania and Türkiye, although according to Jinko ESS, the contracts signed cover 400MWh of BESS capacity across multiple utility-scale projects in Eastern Europe.
A signing ceremony was held at the recent Intersolar Europe trade event in Munich, Germany, and announced 1 July. Jinko ESS vice president Anita Li participated in Energy-Storage.news’ annual Year in Review interview series at the end of 2025, discussing Jinko’s expansion into the energy storage sector. The company’s BESS range includes a 5MWh utility-scale product as well as commercial and industrial (C&I) solutions.
OX2 invests in co-located BESS for its first wind farm in Sweden
BESS developer and engineering, procurement and construction (EPC) OX2 will invest in and begin construction on a 50MW/209MWh project at a wind farm in Sweden.
Sweden-headquartered OX2 decided in March to invest SEK3 billion (US$309.1 million) in Fageråsen, its first wind farm project. It has now decided to co-locate the wind generation facility with batteries. The developer will own both wind and BESS assets.
“The combination of wind and energy storage enables better alignment of production with demand and ensures more efficient use of the electricity generated,” OX2 CEO Matthias Taft said.
“In this way, we do not only add new renewable capacity but also contribute to a more resilient and future-proof energy system in Sweden.”
OX2 said in an announcement 2 July that it has secured financing from banks DNB and UniCredit for the energy storage project, with the financiers extending their lending commitment to Fageråsen wind farm to cover it.
OX2, which recently contracted with Fluence for the supply and integration of BESS at a 50MW/120MWh project in Poland, will procure the wind farm’s battery storage from Trina Solar’s energy storage subsidiary Trina Storage. Construction is due to begin shortly, and commissioning is expected by the end of 2027.
Baltic Storage Platform completes second 100MW project in Estonia
Baltic Storage Platform, a joint venture (JV) between three European companies, has completed its second 100MW/200MWh BESS project in Estonia.
The Hertz 2 project was officially inaugurated yesterday (7 July) in Aruküla, in Estonia’s Harju County, by partners Evecon, Corsica Sole and international investment fund Mirova.
The Baltic countries have seen a rise in BESS development, particularly since the region’s decoupling from the BRELL grid shared with Russia and Belarus and synchronisation with the European electricity network.
Baltic Storage Platform secured financing for Hertz 2 and its equally sized sibling project, Hertz 1, in late 2025. Hertz 1 entered commercial operation in February. The JV said that in addition to helping balance the grid, Hertz 2 will enter into day-ahead and intraday electricity trading markets.
Karl-Joonatan Kvell, CEO of developer Evecon, said the two projects represent the largest private sector investment into Estonia’s energy sector to date with a total value of EU170 million. The CEO said that together with French independent power producer (IPP) Corsica Sole, the decision to invest was made “100% against the market, without any subsidies, taking on all the risks ourselves”.
Andres Sutt, Estonia’s Minister of Energy and the Environment, noted of the projects that such foreign investments are “of invaluable importance in developing our economy, and we must safeguard it so that new investments from friendly foreign countries keep coming our way in the future”.
“At the same time, the Hertz 1 and Hertz 2 BESS projects are important for balancing the entire power system and for bringing more renewable electricity to the market — this is exactly the kind of flexible capacity that Estonia needs more and more at a time when the Baltic States maintain their own frequency,” Sutt said.