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 15 – 21, 2026.
The optimal strategy earned €5.99 over the week versus €1.54 for the basic timer — a +288% uplift, projecting to roughly €273 per year for a single 10 kWh battery cycled once per day.
Average temperature was 24.0°C, with 49 hours of strong sunshine (solar ≥ 200 W/m²), average wind 8.8 km/h, and 26.0 mm of rainfall over the week.
Solar irradiance and spot price correlated at r=-0.75 (solar lowers prices), wind at r=-0.11 (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 |
|---|---|---|---|---|
| 2026-08-14 | €0.00 | €0.00 | 0.0 ct/kWh | 23°C · ☀ 0 W/m² · 💨 3 km/h |
| 2026-08-15 | €1.57 | €0.24 | 17.5 ct/kWh | 27°C · ☀ 816 W/m² · 💨 9 km/h |
| 2026-08-16 | €1.43 | €0.41 | 15.9 ct/kWh | 27°C · ☀ 789 W/m² · 💨 6 km/h |
| 2026-08-17 | €0.55 | €0.15 | 6.1 ct/kWh | 24°C · ☀ 572 W/m² · 💨 11 km/h |
| 2026-08-18 | €0.57 | €0.19 | 6.4 ct/kWh | 20°C · ☀ 462 W/m² · 💨 11 km/h |
| 2026-08-19 | €0.68 | €0.25 | 7.5 ct/kWh | 24°C · ☀ 603 W/m² · 💨 10 km/h |
| 2026-08-20 | €0.65 | €0.16 | 7.2 ct/kWh | 24°C · ☀ 761 W/m² · 💨 6 km/h |
| 2026-08-21 | €0.53 | €0.14 | 5.9 ct/kWh | 23°C · ☀ 682 W/m² · 💨 9 km/h |
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