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: July 11 – 17, 2026.
The optimal strategy earned €6.83 over the week versus €1.92 for the basic timer — a +255% uplift, projecting to roughly €311 per year for a single 10 kWh battery cycled once per day.
Average temperature was 25.6°C, with 77 hours of strong sunshine (solar ≥ 200 W/m²), average wind 7.9 km/h, and 5.0 mm of rainfall over the week.
Solar irradiance and spot price correlated at r=-0.61 (solar lowers prices), wind at r=-0.49 (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 |
|---|---|---|---|---|
| 2026-07-10 | €0.00 | €0.00 | 0.0 ct/kWh | 24°C · ☀ 0 W/m² · 💨 2 km/h |
| 2026-07-11 | €1.36 | €0.17 | 15.2 ct/kWh | 25°C · ☀ 810 W/m² · 💨 9 km/h |
| 2026-07-12 | €1.26 | €0.26 | 14.0 ct/kWh | 24°C · ☀ 613 W/m² · 💨 12 km/h |
| 2026-07-13 | €0.79 | €0.21 | 8.8 ct/kWh | 26°C · ☀ 863 W/m² · 💨 10 km/h |
| 2026-07-14 | €0.71 | €0.26 | 7.9 ct/kWh | 26°C · ☀ 853 W/m² · 💨 7 km/h |
| 2026-07-15 | €0.75 | €0.28 | 8.3 ct/kWh | 26°C · ☀ 807 W/m² · 💨 7 km/h |
| 2026-07-16 | €1.33 | €0.66 | 14.8 ct/kWh | 26°C · ☀ 758 W/m² · 💨 5 km/h |
| 2026-07-17 | €0.62 | €0.09 | 6.8 ct/kWh | 26°C · ☀ 810 W/m² · 💨 6 km/h |
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