I-SEM Daily Briefing — 25 June 2026

Price Profile #

Std dev €46.13/MWh · Median €133.85/MWh · Periods above €150: 15 of 48 (31%)

Wind is back, and the mean dropped €64 on Wednesday — from €213.03 to €149.31. The median (€133.85) well below the mean reflects the shape: a large block of genuinely cheap daytime periods (€104–141 from 03:00–16:30) suppressed by wind, and a smaller block of expensive evening periods pulling the average back up. The floor at €104.00 is the lowest since Saturday — wind actually moved the market this time.

Price vs Wind #

Mean wind: 26.8% · Range: 6.7%–49.4%

A full wind arc, written perfectly into the price profile. Wind built overnight (10% at 23:00 → 49.4% at 05:00) and prices fell with it (€201 at 23:00 → €104 by 10:30). Then wind declined through the afternoon (49% at 05:00 → 6.7% at 20:30) and prices rose back in lock-step (€104 at 13:30 → €240 at 20:30). Cause and effect over a 24-hour arc — every half-hour the wind dropped, the price rose in mirror image.

Week in Context #

Price Duration Curve #

Periods above €150: 15 (31% of day) · Above €200: 11 (23% of day)

Two distinct populations. 33 periods below €150 — the wind-suppressed daytime, with a flat floor around €104–107. Then 15 expensive periods as wind withdrew, including 11 clearing above €200. The curve has a long flat cheap section at the bottom and a steep spike at the top. Wind created both ends: surplus kept the floor down; withdrawal sent the ceiling up.

Peak / Off-Peak Spread #

Peak avg (07:00–22:00): €147.08/MWh · Off-peak avg: €153.02/MWh · Spread: €-5.94/MWh

Barely negative at €-5.94. Off-peak (€153.02) is hauled up by the 23:00 tail from Wednesday’s scarcity (€201.00) and the late-evening prices staying elevated (€206-226 from 22:00-22:30). The peak window contains both the wind-cheap morning and the expensive evening — they cancel in the average. The label says negative; the intraday range of €136.43 says the day had real structure.

BESS Dispatch Signal #

Simulated 1MW/2MWh battery, one optimal DAM cycle. Gross before network charges and capacity costs.

Charge at €104 at 12:30 — wind at 37.6%, prices flatlined at €104-105 for six hours. Discharge at €240 at 19:30 — wind at 11.2%, evening demand at its peak. €199 gross, ROI 95.4%. Second best BESS day of the week. Unlike Wednesday’s record — which was pure scarcity premium — today’s spread came from wind architecture: charge in the surplus, discharge as wind withdrew. Cleaner and more repeatable.

Commentary #

Wind returned and the market felt it immediately. Mean €149.31 — down €64 on Wednesday’s record. The day has a satisfying symmetry: wind built through the night (10% → 49% by 05:00), suppressed prices through the daytime (€104-141 from 03:00-16:30), then declined through the afternoon (49% → 6.7% by 20:30) as demand peaked, driving the evening to €240.

Wednesday’s scarcity still cast a shadow — the 23:00 open (€201.00) was the tail of the previous day’s extreme, and overnight prices didn’t fully clear until wind hit 30%+ after 03:00. From there, the wind did what it’s supposed to: suppress the merit order, bring the floor down to €104, give consumers cheap electricity through the working day.

The evening spike is wind leaving at the wrong time, again. But at €240 versus Wednesday’s €414, it’s orderly. Two consecutive days of wide BESS swings — €388 gross on Wednesday, €199 on Thursday. The system rewards storage when wind is volatile. The system needs wind to stay through the evening.