I-SEM Daily Briefing — 17 September 2026

Market Snapshot

Metric	Value
Mean DAM Price	€147.56/MWh
Median Price	€156.84/MWh
Std Dev	€75.03/MWh
Peak Price	€280.0/MWh (21:00)
Min Price	€22.16/MWh (12:30)
Price Range	€257.84/MWh
Periods above €150	32 of 48 (67%)
Periods above €200	12 of 48 (25%)
Peak Avg (07–22)	€132.84/MWh
Off-peak Avg (22–07)	€172.11/MWh
Peak/Off-Peak Spread	€-39.27/MWh
Cheap/Dear Spread	€23.66/MWh → €265.66/MWh (€242.0)
Wind % of Demand	48.2%
Wind Range	34.5%–55.5%
Mean Demand	3999 MW

Price Profile #

Std dev €75.03/MWh · Median €156.84/MWh · Periods above €150: 32 of 48 (67%)

Price vs Wind #

Mean wind: 48.2% · Range: 34.5%–55.5%

Week in Context #

Price Duration Curve #

Periods above €150: 32 (67% of day) · Above €200: 12 (25% of day)

Peak / Off-Peak Spread #

Peak avg (07:00–22:00): €132.84/MWh · Off-peak avg: €172.11/MWh · Spread: €-39.27/MWh

Cheap window: €23.66/MWh · Dear window: €265.66/MWh · Spread: €242.0/MWh — the actual cheapest and dearest 2-hour blocks of the day, wherever they fall on the clock

Commentary #

This is what cannibalisation looks like. Wind held 44-55% all day and the midday bottom fell out: €22.16 at 12:30, and sub-€30 from 11:30 through 14:30. Big wind + midday demand lull → the clearing price falls through the gas units and down into the renewable end of the merit order.

Overnight had the same wind but only got to €153. The evening came back hard once wind eased to 39%, peaking at €280 at 21:00. Mean of €147.56, but a cheap/dear spread of €242. Charge at €24, discharge at €266.

Best battery day of the fortnight by a distance. Give us another one Friday.

Half-hourly data — 2026-09-17

Period	Time	Price (€/MWh)	Wind %
1	23:00	181.20	35.4%
2	23:30	179.00	34.5%
3	00:00	167.74	52.3%
4	00:30	164.97	51.5%
5	01:00	153.68	51.0%
6	01:30	153.00	51.8%
7	02:00	157.28	51.8%
8	02:30	156.35	51.8%
9	03:00	155.82	52.0%
10	03:30	155.82	51.2%
11	04:00	156.40	50.7%
12	04:30	156.35	50.1%
13	05:00	155.34	50.1%
14	05:30	159.85	50.6%
15	06:00	187.53	55.5%
16	06:30	196.02	53.0%
17	07:00	201.00	49.8%
18	07:30	200.90	52.2%
19	08:00	189.89	51.4%
20	08:30	171.90	51.3%
21	09:00	137.67	49.9%
22	09:30	123.10	48.8%
23	10:00	76.25	50.7%
24	10:30	57.03	49.0%
25	11:00	33.08	48.3%
26	11:30	27.00	44.8%
27	12:00	23.34	48.0%
28	12:30	22.16	47.4%
29	13:00	25.56	45.6%
30	13:30	23.57	45.0%
31	14:00	24.06	43.6%
32	14:30	24.51	44.0%
33	15:00	45.64	50.5%
34	15:30	54.06	54.9%
35	16:00	108.65	55.0%
36	16:30	123.77	53.6%
37	17:00	165.00	52.3%
38	17:30	179.57	49.8%
39	18:00	208.86	51.1%
40	18:30	217.02	51.0%
41	19:00	220.53	49.8%
42	19:30	238.30	45.9%
43	20:00	255.00	43.3%
44	20:30	273.85	39.8%
45	21:00	280.00	38.8%
46	21:30	253.78	37.5%
47	22:00	250.00	38.3%
48	22:30	211.60	38.5%