The BESS Tracker covers 90% of publicly disclosed deals. It specifically includes two broader sets of deals involving BESS assets:
BESS revenue optimisation agreements, where the opitmiser/buyer manages the BESS asset’s participation across different markets in return for a share of the revenues or where the two parties exchange cashflows backed by the contracted BESS asset. Such agreements can take the form of fixed-price arrangements, including tolling agreements and revenue floors, merchant structures with revenue share, or other contractual arrangements, such as day-ahead swaps.
BESS optimisation agreements can apply to both standalone BESS as well as co-located BESS. In the case of co-location, the BESS asset is under an explicit optimisation agreement, separate from the renewable asset's route-to-market arrangements.
We distinguish between single-asset and portfolio deals.Hybrid power offtake agreements for BESS co-located with renewable assets where the BESS asset shares contractual arrangements with the co-located renewable asset and mainly performs a profile-shaping function. In this case, such deals are also featured in Pexapark’s PPA Tracker.
Across all deals included in the tracker, Only the contracted capacity (MW) and contracted energy (MWh) are reported, rather than the asset’s total installed capacity and energy. Additionally, the BESS duration is displayed to provide further context.
The comment icon provides additional context on the deal, including the market application of the contracted assets (e.g., wholesale trading and ancillary services) when this information has been publicly disclosed by the involved parties. It also includes general remarks about the deal and, where available, a link to the primary source for further reference.
Encyclopaedia / Storage & Hybrid Definitions
Contract structure | Definition |
Toll | In physical tolls, the optimiser (or ‘toller’) physically operates the whole or a part of a BESS asset, taking full responsibility for dispatch and market participation. In return for granting physical control of the asset, the owner receives a fixed fee (or a ‘toll’) in EUR/MW or EUR/MWh. Physical tolls shift merchant and performance risks to the optimiser, while the asset owner ensures stable and predictable return.
Virtual tolls are financial contracts, where the optimiser or ‘toller’ guarantees a fixed payment without taking physical control of the asset. In return, the optimiser receives the value between their nominated positions in short-term markets. In contrast to physical tolls, the owner retains the physical control of the asset and can retain the upside if they can outperform the optimiser’s nominated positions. Some portion of merchant risks shift to the optimiser, whilst the owner retains performance and dispatch risk. |
Floor with revenue share | The optimiser and the BESS asset owner agree on a minimum income on the asset operation, typically on a EUR/MW basis. In return for providing downside protection to the asset owner, the optimiser takes a greater percentage of the revenue/profit than would be agreed in a merchant offtake. The asset owner receives a guaranteed payment but is not fully insulated from market risk. |
Merchant revenue share | Such agreements are based on an agreed % revenue share. The optimiser manages the BESS asset operations and receives a percentage of the profits as a fee. Both parties share market risks, as the owner does not receive guaranteed payments. Merchant contracts tend to be short-term and rely on market performance. |
Emerging | This category primarily includes financial hedging products such as day-ahead swaps or other innovative, non-standard contractual structures. In a typical BESS day-ahead swap, the asset owner receives a fixed payment in return for a contractually defined floating value from the other party - for example, the spread between the highest and lowest priced hour. While swaps have not been common in Europe so far, they are already used in the US and Australia. |
Hybrid PPA (Co-location) | The two assets share contractual agreements. Such a deal aims to mimic the demand of a particular offtaker who’s interested, for example, in structures similar to Fixed-Hourly Profile delivery or Baseload PPAs. Pricing could be variable, with different pricing levels for each MWh, depending on when it’s delivered. These are not common the European market. |