The wind left on Tuesday, and Wednesday's bill came due

On Sunday, a storm blew across Germany and power was almost free. Today it is not. The German-Luxembourg day-ahead price for delivery on Wednesday 28 October averages €249.21 per megawatt hour, according to SMARD, the Bundesnetzagentur’s data portal¹. On Sunday 25 October it averaged €13.12¹. It is the dearest day since 14 September, when the average reached €256.55¹. Desk arithmetic: today’s power costs about nineteen times Sunday’s.

Yesterday evening’s note reported the auction result. This morning SMARD has added the other half of the story: what the plants actually did on Tuesday, the day the wind dropped¹. It explains the price better than any speech will today.

The wind halved. Onshore wind turbines generated 1,019,966 megawatt hours on Sunday and 440,623 MWh on Tuesday¹. Offshore farms added 92,072 MWh on Sunday and 147,903 MWh on Tuesday¹. Desk arithmetic: onshore output fell by about 57%, and wind as a whole went from about 1.11 million MWh to about 0.59 million. On Sunday, wind’s output equalled about 93% of the day’s grid load of 1,192,490 MWh. On Tuesday it equalled about 44% of 1,350,195 MWh¹.

Demand rose at the same time. Tuesday was a working day. Grid load was about 13% higher than on Sunday, by desk arithmetic from SMARD’s figures¹. Less wind and more demand at once is the combination that empties a cheap order book. Solar helped a little in the daylight hours: 170,477 MWh on Tuesday, against 87,288 MWh on Sunday¹. In late October that does not reach the evening.

The old plants filled the gap. Lignite generated 54,346 MWh on Saturday and 221,258 MWh on Tuesday¹. Gas-fired plants went from 42,456 MWh to 144,502 MWh over the same days¹. Desk arithmetic: lignite output about quadrupled, and gas output rose about 3.4 times. Gas matters most here, because the last plant needed to meet demand tends to set the price for every hour it runs, and that plant is often a gas plant.

And gas is dear. The November TTF contract, Europe’s benchmark gas price, closed at €96.68 per MWh on Monday, up 3.02% on Friday, and briefly touched €97.40 on Tuesday, 3e-news reports². EU storage is about 75% full, the lowest level recorded for the season, and German storage just 61%, according to the same report, which also cites unplanned disruptions to Norwegian supply². Overnight the oil market added its own worry. Brent rose $1.48 to $115.36 a barrel early on Wednesday, CNBC reports, after Yemen’s Houthis said they had hit Saudi Arabia’s biggest refinery with a missile³. Saudi authorities had not confirmed the strike³.

What it means for you. Desk arithmetic: at €249.21 per MWh, a kilowatt hour on the wholesale market costs about 24.9 cents today, before network charges, taxes and levies. On Sunday it cost about 1.3 cents. If you are on a fixed tariff, your supplier usually bought much of your power well in advance, and today’s auction reaches you slowly and averaged out. If you are on a dynamic tariff, the timing of the dishwasher actually matters this week. Check the hourly prices on SMARD before you plan heavy loads¹.

The contrarian point. Days like today invite two speeches. One says wind power is unreliable because it stopped. The other says the market is broken because the price rose. Both miss what the numbers show. The system kept the lights on through a nineteenfold price swing without drama: the storm weekend switched the old coal plants down, and the still Tuesday switched them back up within days¹. That is the dull machinery working.

What the swing really prices is the gap between Sunday and Wednesday. Every megawatt hour that could have been stored at €13 and sold at €249 is a business case, written in public, on a government data portal, every day. Batteries, flexible industrial shifts, heat stores and interconnectors are not slogans. They are the people who will earn that spread, and in earning it, narrow it.

The price for Thursday will be set at midday today¹. Nobody needs to forecast it. You can read it on SMARD by lunchtime. Nothing here is investment advice.