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 22 – 28, 2026.
The optimal strategy earned €7.35 over the week versus €1.35 for the basic timer — a +443% uplift, projecting to roughly €335 per year for a single 10 kWh battery cycled once per day.
Average temperature was 22.4°C, with 65 hours of strong sunshine (solar ≥ 200 W/m²), average wind 8.5 km/h, and 0.9 mm of rainfall over the week.
Solar irradiance and spot price correlated at r=-0.62 (solar lowers prices), wind at r=-0.25 (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 |
|---|---|---|---|---|
| 2026-08-21 | €0.00 | €0.00 | 0.0 ct/kWh | 18°C · ☀ 0 W/m² · 💨 21 km/h |
| 2026-08-22 | €1.54 | €0.18 | 17.1 ct/kWh | 21°C · ☀ 661 W/m² · 💨 13 km/h |
| 2026-08-23 | €1.69 | €0.49 | 18.8 ct/kWh | 21°C · ☀ 676 W/m² · 💨 4 km/h |
| 2026-08-24 | €0.98 | €0.17 | 10.9 ct/kWh | 21°C · ☀ 664 W/m² · 💨 6 km/h |
| 2026-08-25 | €0.62 | €0.18 | 6.9 ct/kWh | 21°C · ☀ 480 W/m² · 💨 9 km/h |
| 2026-08-26 | €0.77 | €0.18 | 8.6 ct/kWh | 23°C · ☀ 732 W/m² · 💨 6 km/h |
| 2026-08-27 | €0.84 | €0.01 | 9.3 ct/kWh | 24°C · ☀ 715 W/m² · 💨 7 km/h |
| 2026-08-28 | €0.91 | €0.15 | 10.1 ct/kWh | 26°C · ☀ 725 W/m² · 💨 15 km/h |
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