Average deviation depending on the number of days in advance (last 12 complete months):
| Month | 1 day ahead | 2 days ahead | 3 days ahead | 4 days ahead |
|---|---|---|---|---|
| October 2025 | – | – | – | – |
| November 2025 | – | – | – | – |
| December 2025 | 4.18 ct/kWh | 3.4 ct/kWh | 3.72 ct/kWh | 3.8 ct/kWh |
| January 2026 | 3.16 ct/kWh | 3.16 ct/kWh | 2.95 ct/kWh | 3.14 ct/kWh |
| February 2026 | 3.97 ct/kWh | 3.61 ct/kWh | 3.56 ct/kWh | 3.74 ct/kWh |
| March 2026 | 3.09 ct/kWh | 3.05 ct/kWh | 3.01 ct/kWh | 3.09 ct/kWh |
| April 2026 | 3.35 ct/kWh | 3.43 ct/kWh | 3.43 ct/kWh | 3.44 ct/kWh |
| May 2026 | 3.59 ct/kWh | 3.57 ct/kWh | 3.53 ct/kWh | 3.64 ct/kWh |
| June 2026 | 4.14 ct/kWh | 4.13 ct/kWh | 4.16 ct/kWh | 4.24 ct/kWh |
| July 2026 | 5.02 ct/kWh | 5.08 ct/kWh | 4.99 ct/kWh | 5.07 ct/kWh |
| August 2026 | 7.05 ct/kWh | 6.99 ct/kWh | 6.97 ct/kWh | 7.05 ct/kWh |
| September 2026 | 8.79 ct/kWh | 8.51 ct/kWh | 8.27 ct/kWh | 8.64 ct/kWh |
| Ø Total (12 months) | 4.63 ct/kWh | 4.49 ct/kWh | 4.46 ct/kWh | 4.59 ct/kWh |
Last 14 days: Where were the 4 cheapest hours per day according to the forecast (green) – and where actually (blue)? Overlaps show accuracy.
Scenario: Your EV arrives on Wednesday at 6pm with an empty battery. We compare three optimization strategies:
Day-Ahead Market
352.84 €
Annual savings with weekly charging
Available at noon for the next day
Based on 52 charges per year (40 kWh)
Free
387.99 €
Annual savings with weekly charging
Planning: 2 full days
10% more savings!
Based on 52 charges per year (40 kWh)
Premium Feature
458.79 €
Annual savings with weekly charging
Planning: 6 full days
18% more savings!
Based on 52 charges per year (40 kWh)
The annual savings were calculated as the difference between immediate charging (Wednesday 6pm) and charging during the 4 cheapest hours in the respective forecast period.
Optimization only possible until Thursday (Day-Ahead prices available at noon for next day)
Optimization from Wednesday 6pm to Friday 6pm possible (48h forecast horizon)
Optimization from Wednesday 6pm to Tuesday 6pm possible (6 day forecast horizon)
Savings = (Immediate charging Wednesday 6pm - price of 4 cheapest hours in forecast period) × 40 kWh
Actual annual savings may vary depending on your electricity tariff, charging speed and charging behavior. We simulate a user who charges their 40 kWh car once a week.
Exchange electricity prices: Bundesnetzagentur | SMARD.de, license CC BY 4.0. Forecasts and prices including grid fees, levies and taxes are calculated by energyforecast.de on this basis.