Germany could need 10 GW to 14 GW of bankable BESS tolling capacity by the mid-2030s, according to a PwC and FfE whitepaper
As of May 2026, independent developers accounted for 69% of the country’s installed BESS capacity, increasing the importance of debt financing and predictable revenues
Authors recommend that higher fixed tolling payments, a greater share of capacity under contract and longer agreement terms can improve the cash flow certainty
Germany could require 10 GW to 14 GW of battery energy storage system (BESS) tolling capacity by the mid-2030s to support the financing of its growing storage pipeline, according to a joint white paper by PricewaterhouseCoopers (PwC) and the Research Centre for Energy Economics (FfE).
The whitepaper titled Challenges in Financing and De-Risking BESS Projects, highlights the growing importance of tolling agreements as battery storage developers increasingly depend on debt financing.
Germany’s large-scale BESS capacity is expected to expand significantly. The country’s current grid development plan assumes installed capacity will reach 40 GW by 2037, while FfE expects expansion to up to 28 GW by the mid-2030s. The report also anticipates a shift in storage duration: while installations in the coming years are likely to have durations of around two hours, new projects from the 2030s onwards are expected to increasingly feature around four hours of storage, reflecting changing flexibility requirements.
Much of this expansion is driven by independent project developers, according to the whitepaper. Referring to Germany’s Market Data Register, the analysts believe only 31% of the installed capacity of the existing BESS portfolio in Germany was covered by energy supply companies till May 2026, while 69% was realized by independent project developers.
The latter rely on debt financing having limited financing capacities of their own, which the report says is difficult to secure based solely on merchant revenues. Tolling models can help address this financing gap by providing more predictable income, recommend the authors.
“Tolling makes volatile storage revenues more predictable, thus creating an essential prerequisite for bankable financing of BESS projects,” reads the whitepaper.
A recent example of the model’s use in the Asia-Pacific region is Amazon’s tolling agreement with Anza Power for the 50 MW/200 MWh Bairnsdale battery in Australia. The agreement gives Amazon access to the battery’s storage capacity and flexibility without requiring it to own the asset (see Amazon Signs First Battery Storage Tolling Deal In Asia Pacific).
However, the availability of bankable tollers is a key challenge, as they need to offer operational expertise, sufficient risk capital and creditworthiness, points out the whitepaper.
Additionally, flexible connection agreements, changes to network charges and co-location with renewable energy projects could affect battery operations and revenues.
Germany’s proposed AgNes reform of electricity network charges may also have significant implication for project revenues in the future. The reform will require BESS projects commissioned after August 4, 2029 with no qualifying FID, to contribute to network costs (see Germany's AgNes Draft Draws Industry Concerns On Storage FID Timeline).
Such factors and uncertainties could lead tollers to demand higher risk premiums, offer lower payments or impose shorter and more restrictive contract terms.
The authors of the whitepaper explain how tolling terms can affect the debt available to a BESS project. For instance, a higher fixed tolling payment or a larger share of battery capacity covered by the agreement can increase the cash flow available for loan repayments. A longer contract can also give lenders greater certainty over revenues.
The report emphasizes that the tolling agreement, financing terms, manufacturer warranties and technical design must therefore be structured together.
Florian Mayr, Partner, Strategy & Germany, PwC said, “The BESS market not only needs more projects and more capital. It also needs a scalable market for bankable tolling capacity and structures that allow risk to be sensibly distributed between asset owners, tollers and capital providers.”
The authors therefore highlight the need for project-specific financing and tolling arrangements that account for grid connection conditions, technical design and the project’s marketing strategy.
The white paper also identifies potential demand for tolling beyond standalone storage developers. This includes unsubsidized wind and solar plants, large electricity consumers such as data centers and electrolyzers, and certain must-run power plants as market participants that could use tolling structures to manage exposure to volatile electricity prices.
The complete white paper in German is available for free download on FfE’s website.
