Pool Management vs. Virtual Power Plants: Two Aggregation Concepts in Balancing Markets

Why the Distinction Matters

The word "pool" gets used loosely in balancing market discussions, often blurring two very different concepts: pool management toward the TSO, and the aggregation of small assets into a Virtual Power Plant. Both involve operating multiple assets as one resource — but for different reasons, with different requirements. Understanding the difference clarifies what an operator's infrastructure actually has to do.

Pool Management: Coordinating Multiple Assets Toward the TSO

Pool management is the continuous operational coordination of multiple assets that participate in a balancing market product. From the TSO's perspective, the pool is the unit it bids capacity into, communicates with, and verifies performance against.

Pool management applies whenever an operator has more than one asset participating in a balancing product - even if every asset is individually large enough to meet the market's minimum bid size. The TSO does not communicate with every asset separately. It sees the pool as a single bidder, with one capacity offer and one delivery obligation.

In practice, pool management involves:

• Asset integration: connecting each asset to the operational communication infrastructure.

• Real-time monitoring: tracking availability, state of charge, and performance of every asset in the pool.

• Dispatch coordination: distributing TSO control signals across the pool to deliver committed capacity.

• Capacity substitution: covering committed capacity with other assets when one becomes temporarily unavailable.

• Performance verification: documenting that activations were delivered correctly.

Pool management is required regardless of asset size. A pool of three 50 MW standalone BESS sites still requires pool management - even though each asset individually exceeds the minimum FCR bid size of 1 MW.

Virtual Power Plants: Aggregating Small Assets to Reach Minimum Bid Sizes

A Virtual Power Plant is a specific aggregation structure where individual assets are below the minimum bid size required for a market product, and are combined into a single market-facing unit to clear that threshold.

The problem a VPP solves is purely economic. A 200 kW commercial battery, a 500 kW industrial flexibility asset, or a residential storage fleet can each be technically capable of providing FCR or aFRR, but individually none of them meets the 1 MW minimum bid size that applies to FCR, aFRR, and mFRR alike. Without aggregation, they have no path to balancing market revenue at all.

A VPP solves this by presenting a coordinated set of small assets to the TSO as one larger unit. The TSO sees a single entity above the minimum threshold. Internally, the VPP operator distributes activations across the underlying assets in real time.

The Relationship Between the Two

A VPP always requires pool management, but pool management does not require a VPP. The obligations differ in important ways:

• Prequalification: in a VPP, each asset is prequalified as part of a reserve providing group (Reservegruppe) with a dedicated pool concept, since no asset would meet the minimum bid size on its own.

• Substitution rules: VPPs rely much more heavily on substitution between assets to maintain committed capacity, because individual asset failures are more disruptive when capacities are small.

• Bid optimisation: pool-level constraints (combined state of charge, combined ramp rate, individual asset availability windows) drive bid strategy in ways that wouldn't apply to a pool of larger standalone assets.

• Operational scope: in a VPP, capacity is constructed bottom-up from many small contributors; in a standard pool, capacity is contributed top-down by fewer large assets.

Where the Infrastructure Has To Do the Work

Both pool management and VPP operation depend on the same operational backbone: low-latency communication with every asset, accurate real-time telemetry, deterministic dispatch, and pool-level audit trails. The infrastructure layer that supports either must be capable of supporting both, and most professionally operated balancing market participants run both configurations in parallel across different products and asset classes.

Sources: Regelleistung.net, Regelleistung.net, FfE