DNV, the independent energy expert and assurance provider, acted as technical advisor to TotalEnergies to support the sale of a 50 percent stake in an 800 MW portfolio of battery storage projects in Germany to Allianz Global Investors (AllianzGI). The portfolio, comprising 11 projects currently under construction, represents 789 MW / 1628 MWh of capacity and is expected to reach commercial operation by 2028.
The transaction, which values the portfolio at approximately EUR 500 million, represents one of the largest battery storage deals in Germany. The projects will provide critical flexibility to the German power system, helping to integrate renewable energy, reduce grid congestion, and support the country's energy transition goals.
'This transaction demonstrates the vital role of independent technical expertise in large-scale energy infrastructure mergers and acquisitions,' said Prajeev Rasiah, Senior vice-president and Regional Director for Northern Europe, Energy Systems at DNV. 'With a portfolio of this size and complexity, investors require deep confidence in the assets' technology, construction plans, and revenue assumptions. Our team's ability to deliver a thorough and timely vendor due diligence, coordinating experts across multiple disciplines, provided that confidence and enabled a smooth transaction.'
DNV's scope of work included a comprehensive technical due diligence of the 11-project portfolio. The projects include sites such as Weingarten (100 MW/203 MWh), Mehringen (147 MW/296 MWh), and Husum (147 MW/296 MWh). The assignment required coordination from a cross-regional team of DNV experts, covering disciplines from technology assessment to construction and grid connection review. The work was delivered under a tight schedule to meet the transaction timeline.
'Battery storage due diligence requires a detailed understanding of how technology choices, construction timelines, and contractual risk allocation interact at each site', added Iqbal Ahmad Sarabi, Senior energy storage engineer, and the project's manager at DNV. 'In this portfolio, we evaluated project-specific factors such as grid connection, system design, and operational performance, while also ensuring consistency across all 11 assets. This approach is critical to provide investors with a robust view of performance and risk.'
Battery storage is essential to Germany's energy transition. As the country increases its share of renewable generation to 98% of its electricity output by 2050 (DNV Energy Transition Outlook Germany 2050), storage assets provide the flexibility needed to balance supply and demand, stabilize the grid, and ensure reliable power. Under the new joint venture, TotalEnergies and AllianzGI will finance, construct, and operate the projects, contributing to the long-term resilience of Germany's electricity network as it moves towards a decarbonized future.
Source: DNV
