Daily guide · NO1 · 2026-08-30
Charging an EV in Norway Oslo 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.
This week in Oslo the pattern held with unusual consistency: the cheapest charging window averaged 112,57 EUR/MWh, while the evening peak averaged 154,67 EUR/MWh. That is a gap of 27 percent between the best and worst times to plug in, and it recurred on every day in the sample rather than appearing once and fading.
The timing is worth noting. On most days the cheapest window opened around midday, from 12:00 on four of the seven days, with the outliers arriving earlier — 07:00 on 23 August and 01:00 on 28 August. Evenings were reliably the expensive stretch, peaking at 185,82 EUR/MWh on 26 August against a window average of 129,53 EUR/MWh the same day. The single cheapest window came on 29 August at 83,85 EUR/MWh.
The concrete takeaway: for a household charging around 150 kWh a week, shifting from evening to the cheap window saved 6,31 EUR this week, or roughly 328 EUR over a year. If you can schedule charging for the midday hours rather than after dinner, that is where the money sits.
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 NO1 this week.
27%
cheaper to charge in the best 3h window than at the evening peak, on average this week
112.57 vs 154.67
€/MWh: best window vs 18–21h evening habit (week average)
≈€328
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 |
|---|---|---|---|---|
| 2026-08-23 | 07:00–10:00 | 98.81 | 148.18 | −33% |
| 2026-08-24 | 11:00–14:00 | 123.79 | 165.94 | −25% |
| 2026-08-25 | 12:00–15:00 | 120.53 | 172.92 | −30% |
| 2026-08-26 | 12:00–15:00 | 129.53 | 185.82 | −30% |
| 2026-08-27 | 12:00–15:00 | 118.63 | 146.73 | −19% |
| 2026-08-28 | 01:00–04:00 | 112.87 | 130.14 | −13% |
| 2026-08-29 | 12:00–15:00 | 83.85 | 132.93 | −37% |
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": "NO1", "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; public pages and widgets let you inspect the data before subscribing. 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-no1-2026-08-30".
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