For a 10 kWh home battery in Austria, this analysis uses real day-ahead EPEX spot prices (via aWATTar) and Vienna weather (via Open-Meteo) to compare an AI-optimised charge/discharge strategy against a basic time-of-day timer. Period covered: August 29 – 4, 2026.
The optimal strategy earned €8.86 over the week versus €1.35 for the basic timer — a +555% uplift, projecting to roughly €404 per year for a single 10 kWh battery cycled once per day.
Average temperature was 23.8°C, with 65 hours of strong sunshine (solar ≥ 200 W/m²), average wind 8.4 km/h, and 5.1 mm of rainfall over the week.
Solar irradiance and spot price correlated at r=-0.64 (solar lowers prices), wind at r=-0.16 (wind lowers prices). These match what you would expect: more renewable feed-in pushes prices down, so the optimal strategy is to charge during high-renewable, low-price hours and discharge in the evening peak.
| Date | Optimal Strategy | Basic Timer | Spread | Weather |
|---|---|---|---|---|
| 2026-08-28 | €0.00 | €0.00 | 0.0 ct/kWh | 23°C · ☀ 0 W/m² · 💨 13 km/h |
| 2026-08-29 | €1.71 | €0.53 | 19.0 ct/kWh | 23°C · ☀ 492 W/m² · 💨 9 km/h |
| 2026-08-30 | €1.82 | €0.34 | 20.3 ct/kWh | 25°C · ☀ 741 W/m² · 💨 4 km/h |
| 2026-08-31 | €0.87 | €-0.06 | 9.6 ct/kWh | 24°C · ☀ 515 W/m² · 💨 7 km/h |
| 2026-09-01 | €0.98 | €0.20 | 10.9 ct/kWh | 23°C · ☀ 599 W/m² · 💨 10 km/h |
| 2026-09-02 | €1.25 | €0.20 | 13.9 ct/kWh | 23°C · ☀ 717 W/m² · 💨 5 km/h |
| 2026-09-03 | €0.91 | €0.03 | 10.1 ct/kWh | 24°C · ☀ 545 W/m² · 💨 11 km/h |
| 2026-09-04 | €1.30 | €0.10 | 14.5 ct/kWh | 26°C · ☀ 697 W/m² · 💨 12 km/h |
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