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Flexibility Aggregation

Flexibility Aggregation

Flexibility matching is the process by which buy bids and sell offers are paired in the market. Matching operates across two domains simultaneously: quantity (or power) and time.

The market currently fulfills seller asks completely against buyer bids — a sell order is always consumed in full when matched. However, a single large buyer bid may be matched against several smaller seller offers, which means the bid must be progressively split during the matching process.

No aggregation scenarios

Splitting a Bid

´´´´´ Whenever a bid is matched with a sell order, the bid is divided:

  • The portion covered by the sell order is consumed.
  • The remaining portions are split into one or more smaller bids and re-entered into the matching process.

Depending on the degree of overlap in the time domain and the quantity (power) domain, a bid is split into a minimum of one new bid with a shorter time duration, and up to two or three new bids.

Split Strategies

There are two fundamental approaches to splitting a bid during continuous matching.

Option 1 — Time-Domain Split

The bid is divided first along the time axis. The matched interval (where the sell order overlaps in time) is separated from the remainder. This produces sub-bids that cover distinct, non-overlapping time windows.

Figure 1

Image to be added: illustration of a bid split along the time axis.

Option 2 — Quantity (Power) Domain Split

The bid is divided first along the quantity (power) axis, as specified in the initial order. The matched quantity is separated from the unmatched quantity. Sub-bids with distinct power levels but potentially overlapping time intervals are re-queued.

Figure 2

Image to be added: illustration of a bid split along the quantity/power axis.

Resulting Sub-Bids After a Match

After a sell order is consumed by a bid, the remaining unmatched portions are returned to the queue as new, smaller bids. The number of resulting sub-bids depends on the spatial overlap of the original bid and the sell order in both domains:

Overlap scenario Resulting new bids
Full overlap in both domains 0 new bids (bid fully consumed)
Partial overlap in one domain only 1 new bid (reduced time or quantity)
Partial overlap in both domains 2–3 new bids

This process repeats continuously until the original bid is fully matched or no suitable sell orders remain.

Aggregation stages

Summary

Original Bid
    │
    ▼
Matched with Sell Order
    │
    ├── Matched portion → Consumed ✓
    │
    └── Remaining portion(s)
            │
            ├── Split in Time Domain   → New bid(s) with shorter duration
            └── Split in Power Domain  → New bid(s) with reduced quantity
                        │
                        ▼
              Re-entered into matching queue