Partners Group investing €400 million in German BESS platform ‘green flexibility’

January 16, 2025
LinkedIn
Twitter
Reddit
Facebook
Email

Private equity firm Partners Group has invested in ‘green flexibility’, a BESS platform in Germany, with an initial equity commitment of €400 million (US$411 million).

With the equity commitment and complementary debt financing, green flexibility will have over €1 billion to invest in its pipeline of battery energy storage system (BESS) projects in Germany, some of which are already under construction.

The firm specialises in developing and operating large-scale BESS for stabilising the grid and reducing curtailment, and it aims to establish itself as a leading independent flexibility provider (IFP) by monetising its storage capacity through long-term contracts. It said it will benefit from growth trends in Germany, which now has 100GW of PV online and aims to more than double that by 2030.

Green flexibility was founded by CEO Christoph Ostermann. He was one of the founders of sonnen, the virtual power plant (VPP) aggregator where he spent ten years until 2021, and is also on the board of numerous Germany clean energy technology firms including solar PV manufacturer 1KOMMA5 and flexibility services provider Esforin.

This article requires Premium SubscriptionBasic (FREE) Subscription

Enjoy 12 months of exclusive analysis

Not ready to commit yet?
  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Annual digital subscription to the PV Tech Power journal
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

Commenting on the deal, Ostermann said: “Long-term reliability, the highest safety standards, and the
best technology are critical—because the energy transition needs stability and dependability. And for this, we have assembled the most experienced team in the market.”

The firm’s commercialisation strategy appears similar to that which is conventional in the Dutch market, where BESS projects are rented out in slices to different parties to use that flexibility (explained in a recent Premium article).

Shift in profile of owner-operators in German BESS market

The announcement speaks to an evolution and maturation in the types of companies driving the deployment of large-scale BESS projects in Germany.

When Energy-Storage.news did a deep-dive into the German BESS market in 2022, the main companies that had deployed or were building large-scale BESS were legacy utilities and independent power producers (IPPs) like RWE and LEAG. A big challenge highlighted by one market source back then was simply a lack of companies investing in and building BESS.

Since then, clean energy developer-operators like Gore Street Capital, Aquila Clean Energy, Nofar Energy have entered the market while new, BESS specialists like green flexibility, Eco Stor, and Terralyr have entered the scene too. Eco Stor has been around for several years, but only recently shifted to owning its own operational projects, having mainly done engineering, procurement and construction (EPC) previously.

The German market is also evolving in numerous other ways. In a recent post on LinkedIn post, system integrator Fluence’s Lars Stephen pointed to the first GWh-scale projects soon coming online, 4-hour systems coming to market, saturating still not hitting the market and DSOs increasingly opting for BESS as four major trends for 2025.

2 December 2025
NH Collection Vittorio Veneto, Rome, Italy
Across two packed days, the Summit focused on three core themes: revenue & trading, the lifecycle of the battery, and optimisation tools. Attendees explored innovative strategies for enhancing asset performance and longevity, with a spotlight on key markets like Germany, Italy, and the UK. Stay tuned for details on the 2025 edition of the Battery Asset Management Summit Europe, where we’ll continue to chart the path forward for energy storage asset management.
24 February 2026
InterContinental London - The O2, London, UK
This isn’t just another summit – it’s our biggest and most exhilarating Summit yet! Picture this: immersive workshop spaces where ideas come to life, dedicated industry working groups igniting innovation, live podcasts sparking lively discussions, hard-hitting keynotes that will leave you inspired, and an abundance of networking opportunities that will take your connections to new heights!

Read Next

October 31, 2025
Lithium-ion OEM Envision Energy has launched its latest grid-scale BESS solution, a 10-foot modular DC block which can be combined into configurations of 12MWh or more.
October 31, 2025
The European Bank for Reconstruction and Development (EBRD) has provided US$142 million in financing for the construction of a 1GW solar and 1.3GWh battery energy storage system (BESS) portfolio in Uzbekistan.
October 30, 2025
Power firm RWE has launched construction on a 400MW/700MWh BESS project in Bavaria, Germany, the largest being built in the country.
October 30, 2025
Victoria’s home battery energy storage programme has supported the installation of approximately 20,000 residential energy storage systems, doubling its original target of 10,000 units, according to the state’s climate action minister, Lily D’Ambrosio.
October 29, 2025
IPPs Greenvolt and European Energy have finalised financial deals for solar-plus-storage projects in Denmark and Latvia, while Olana and Energix have enlisted optimisers for BESS projects in Lithuania and Poland, respectively.

Most Popular

Email Newsletter