I-SEM Daily Briefing — 6 June 2026

Price Profile #

Std dev €24.82/MWh · Median €121.16/MWh · Periods above €150: 2 of 48 (4%)

A calm Saturday with another record-low trough. Mean €114.35, peak only €152.00 at 19:30, min €69.92 at 14:30. Range €82.

Boundary periods at €139 and €134 are Friday’s evening tail crossing in. Then a clean descent through overnight (€118–128 from 01:00 to 05:30, wind 47-67%) into the morning — but no morning peak. €109 at 07:00 → €102 at 08:00 → €89 at 11:00 → €70 at 14:30. The midday trough goes deeper than yesterday’s because Saturday demand is suppressed.

Evening rebuilt €73 at 15:30 → €152 at 19:30, holding €148–152 across 19:00 to 21:00. Just two periods crossed €150.

Wind held 30–67% — recovered through late afternoon and evening, which capped the evening peak.

Price vs Wind #

Mean wind: 43.9% · Range: 30.3%–67.3%

Wind shape: high overnight (54-67% in the early hours), drained to a midday low of 30% around 10:30-11:00, recovered to 50%+ from 15:30 onward.

The midday trough (€69.92) happens at the low wind point of the day for the first time in the run. Counter-intuitive — but the explanation is demand: Saturday midday demand was at its weekend minimum, so even 30% wind was enough to push the merit order into surplus territory. Wind level doesn’t matter once you’re below the demand-load threshold.

Week in Context #

Three midday-trough record lows in five days: €65.25 (Wed), €37.85 (Thu), €69.92 (Sat). The surplus regime is structural now, not anomalous.

Price Duration Curve #

Periods above €150: 2 (4% of day) · Above €200: 0 (0% of day)

2 above €150, 0 above €200. Almost the all-day-sub-€150 archetype again, just barely missing.

Peak / Off-Peak Spread #

Peak avg (07:00–22:00): €107.59/MWh · Off-peak avg: €125.61/MWh · Spread: €-18.02/MWh

−€18.02 — sixth negative reading in 32 days, and one of the more extreme ones.

Same structural cause as the May 30 / June 2 / June 3 readings. Boundary catches Friday’s tail; midday trough sits inside the peak window. The metric inverts. The captured spread (€79) is 4.4× the absolute value of the headline.

A negative spread is now appearing every 4-5 days in this regime. Worth a tag on the dashboard.

BESS Dispatch Signal #

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

€112 gross. Cheap charge (€72) does the work again — ROI 78.2% on a modest discharge (€150). The same pattern as June 4 in miniature.

35-day cumulative: €3,504, mean €100/day.

Commentary #

Another deep midday trough — €69.92 at 14:30, the third record low this week after €37.85 on Thursday and €65.25 on Wednesday. Calm Saturday, weekend demand at 3,608 MW, wind 30-67% with the lowest point at midday.

The structural feature: wind at 30% in midday produced a deep trough today because Saturday demand was suppressed enough that even moderate wind cleared the merit order. Wind level doesn’t matter when you’re below the demand-load threshold — what matters is whether wind exceeds the variable cost of the next plant on the stack.

BESS €112 — solid day, cheap charge unlocks the ROI. Negative peak/off-peak spread again (−€18.02, the run’s sixth). The metric is broken often enough now that a permanent flag on the dashboard is overdue.