Daily guide · SK · 2026-08-27
Charging an EV in Slovakia 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 is the gap between midday and evening. The cheapest charging windows averaged 84,50 EUR/MWh, while evening peaks averaged 213,34 EUR/MWh, a difference of 60 percent. For an EV driver, that spread is the whole story: when you charge matters far more than how much you charge.
Two days stand out. On 22 August the midday window averaged 0,33 EUR/MWh and on 23 August it averaged 1,75 EUR/MWh, effectively free power around midday. Yet the same evenings held near 194,32 and 199,18 EUR/MWh. The cheap windows mostly opened between 09:00 and 13:00, while evening prices never dropped below the 194 EUR/MWh mark all week, peaking at 235,70 EUR/MWh on 24 August.
The concrete takeaway: shift your charging into the midday window rather than plugging in after work. On a weekly load of 150 kWh, moving to the cheap window instead of the evening peak was worth 19,33 EUR this week, and roughly 1.005 EUR over a year. If you have any daytime access, a charger, a workplace socket, a timer, this is where the money is.
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 SK this week.
60%
cheaper to charge in the best 3h window than at the evening peak, on average this week
84.5 vs 213.34
€/MWh: best window vs 18–21h evening habit (week average)
≈€1005
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 |
|---|---|---|---|---|
| 2026-08-20 | 12:00–15:00 | 107.86 | 207.4 | −48% |
| 2026-08-21 | 11:00–14:00 | 139.51 | 222.03 | −37% |
| 2026-08-22 | 12:00–15:00 | 0.33 | 194.32 | −100% |
| 2026-08-23 | 09:00–12:00 | 1.75 | 199.18 | −99% |
| 2026-08-24 | 12:00–15:00 | 83.45 | 235.7 | −65% |
| 2026-08-25 | 12:00–15:00 | 120.07 | 210.25 | −43% |
| 2026-08-26 | 13:00–16:00 | 138.53 | 224.5 | −38% |
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": "SK", "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-sk-2026-08-27".
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