Daily guide · SE3 · 2026-08-03
Charging an EV in Sweden Stockholm this week: what the prices actually said
All numbers computed from the week's published auction results at publication and frozen — this article is an honest snapshot, not a page that rewrites itself. Reproduce via the API.
The clearest signal this week in Stockholm is the gap between the cheapest charging window and the evening peak. The cheap windows averaged 6,97 EUR/MWh, while evening prices averaged 43,52 EUR/MWh — a difference of 84 percent. That spread is where the money is, and it held across most of the week rather than appearing on a single day.
The individual days show how variable the peaks can be. On 29 July the evening average reached 92,48 EUR/MWh, and 30 July followed at 61,97 EUR/MWh, while the corresponding cheap windows sat at 8,03 and 5,67 EUR/MWh. The cheapest single window came on 28 July at 1,54 EUR/MWh. The timing shifted too: some cheap windows opened in the early hours, such as 00:00 on 29 July and 02:00 on 31 July, while others fell around midday or 13:00.
For a driver charging 150 kWh a week, moving load from the evening into these windows was worth 5,48 EUR over the week, or about 285 EUR across a year. The concrete takeaway: set your charger to the flagged window and avoid the evening entirely.
Every day at 13:00 CET, an auction sets electricity prices for every hour of tomorrow — separately, for each European bidding zone. Those prices routinely differ by a factor of two to three within a single day, because solar floods the middle of the day and demand peaks in the evening. If you charge an EV, that spread is money: the car doesn't care when it charges, only that it's full by morning. This is what the spread looked like in SE3 this week.
84%
cheaper to charge in the best 3h window than at the evening peak, on average this week
6.97 vs 43.52
€/MWh: best window vs 18–21h evening habit (week average)
≈€285
a year on the wholesale component, for 150 kWh/week of charging at this week's gap
Day by day: when the cheap window actually fell
| Day | Cheapest 3h window | Window avg €/MWh | Evening 18–21h | Gap |
|---|---|---|---|---|
| 2026-07-27 | 13:00–16:00 | 15.69 | 20.38 | −23% |
| 2026-07-28 | 13:00–16:00 | 1.54 | 34.38 | −96% |
| 2026-07-29 | 00:00–03:00 | 8.03 | 92.48 | −91% |
| 2026-07-30 | 12:00–15:00 | 5.67 | 61.97 | −91% |
| 2026-07-31 | 02:00–05:00 | 4.07 | 38.84 | −90% |
| 2026-08-01 | 13:00–16:00 | 10.24 | 27.24 | −62% |
| 2026-08-02 | 13:00–16:00 | 3.57 | 29.36 | −88% |
Local time. Notice the window MOVES — sometimes after midnight, sometimes midday when solar peaks. A fixed night tariff catches some of this; following the auction catches all of it.
Automate it in ten minutes
You don't need to read auction results at 13:00 every day — ask the API for the cheapest window and let your wallbox follow it. One call:
curl -X POST -H "Authorization: Bearer YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"zone": "SE3", "duration_minutes": 180}' \
https://voltcast.com/api/v1/optimize/cheapest-windowHome Assistant users: the Voltcast integration exposes the same window as a sensor you can automate against; evcc users get a ready-made tariff config. The Home plan (€9/mo) covers one zone of your choice with 7-day forecasts — the free tier lets you test everything on DE-LU first. And if you want to charge on a forecast of tomorrow before the auction even publishes, that's the P50 curve — scored publicly every day so you know exactly how much to trust it.
Method & citation. Prices are hourly means of published day-ahead auction results (native 15-minute periods averaged; ENTSO-E/SMARD, attributed). Wholesale-price component only — grid fees and taxes come on top and vary by supplier. Cite as "Voltcast Research, voltcast.com/guides/ev-charging-se3-2026-08-03".
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