Method note · measured
The daily spread (TB1 and TB2)
What it measures
The daily spread (TB1) is a day's dearest hour minus its cheapest; TB2 averages that gap over the two dearest and two cheapest hours.
Inputs
- The day-ahead price on the canonical hourly grid, for the bidding zone selected on the view
Method and weighting
TB1, the daily spread's first measure, is the day's dearest local hour minus its cheapest, read from the canonical hourly grid for the zone. TB2, the second measure, is the mean of the two dearest hours minus the mean of the two cheapest; on a day with fewer than four hours observed it falls back to the TB1 gap. Negative prices are kept as they are, since producers paying to keep generating is part of what the spread shows. The Negative hours note describes the count of hours below zero.
Window
The rolling 12 months to the last complete day, refreshed on the 1st and 15th of each month. The current window runs from to . Data last refreshed on .
Known limits
- The hourly grid this spread is computed on already averages a quarter-hour market onto the hour, so the gap it reports understates the finer-grained market.
- A day with an hour missing is reported using the hours it has, and is shaded as incomplete on the chart.
Used on
Sources: ENTSO-E. Each is described on the Data sources page.