How reserve capacity is procured, block by block
Before any energy is balanced, the operator has to buy the option to balance it. Reserve capacity is tendered separately from balancing energy, in four-hour blocks, and the offers and awards are published.
Capacity is not energy
A capacity tender buys availability: the commitment to be ready to deliver, priced per MW per hour. It is a different market from the balancing energy the other views cover, cleared on a different timetable, and a unit can win capacity and never be activated.
The date control here reads a tender date rather than a delivery day. For this auction they are the same date, so carrying the parameter across from the other balancing views is correct rather than a coincidence worth guarding against.
Blocks and the award cut
- A block
- A four-hour window of the tender day, per reserve product and direction. Each block clears on its own, so a day carries several independent auctions rather than one.
- The merit order
- One block's offers, cheapest first. Choosing another block redraws the curve for that one.
- The award cut
- The price the last awarded MW cleared at. Everything below it was taken; the cheapest rejected offer above it is the nearest thing to a counterfactual the publication supports.
- Award share
- How much of what was offered was actually taken. This is the figure the whole-day product would distort if it were pooled in - see below.
Why the whole-day product is reported separately
A whole-day product competes for the same reserve across all 24 hours instead of one four-hour block. On the tenders measured it offered many times the requirement, at prices far above what the four-hour blocks cleared at, and was awarded nothing.
Pooling it into the merit order above would put never-competitive volume at the top of every block's curve and make the award-share figures meaningless. So it is reported on its own, with its own table, and only where the tender actually carried one.
What this view does not do
Nothing here is screened or thresholded. No finding is produced and no threshold is applied.
Nothing can be attributed to a participant either, and that is measured rather than assumed: the bid identifier does not thread across tenders. Verified 0 of 25,701 bid ids recurring across 14 tender dates - so the identifier is per-tender bookkeeping and cannot be used to follow anyone between auctions.