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: September 19 – 25, 2026.
The optimal strategy earned €12.67 over the week versus €0.99 for the basic timer — a +1178% uplift, projecting to roughly €577 per year for a single 10 kWh battery cycled once per day.
Average temperature was 16.4°C, with 49 hours of strong sunshine (solar ≥ 200 W/m²), average wind 10.4 km/h, and 13.9 mm of rainfall over the week.
Solar irradiance and spot price correlated at r=-0.60 (solar lowers prices), wind at r=-0.01 (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 |
|---|---|---|---|---|
| 2026-09-18 | €0.00 | €0.00 | 0.0 ct/kWh | 19°C · ☀ 0 W/m² · 💨 8 km/h |
| 2026-09-19 | €1.98 | €-0.07 | 22.0 ct/kWh | 21°C · ☀ 657 W/m² · 💨 4 km/h |
| 2026-09-20 | €1.86 | €0.17 | 20.6 ct/kWh | 21°C · ☀ 631 W/m² · 💨 9 km/h |
| 2026-09-21 | €1.67 | €0.49 | 18.5 ct/kWh | 16°C · ☀ 635 W/m² · 💨 17 km/h |
| 2026-09-22 | €3.67 | €0.41 | 40.8 ct/kWh | 14°C · ☀ 346 W/m² · 💨 15 km/h |
| 2026-09-23 | €1.75 | €-0.12 | 19.4 ct/kWh | 15°C · ☀ 475 W/m² · 💨 9 km/h |
| 2026-09-24 | €0.72 | €0.04 | 8.0 ct/kWh | 13°C · ☀ 170 W/m² · 💨 10 km/h |
| 2026-09-25 | €1.02 | €0.07 | 11.3 ct/kWh | 14°C · ☀ 617 W/m² · 💨 9 km/h |
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