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 12 – 18, 2026.
The optimal strategy earned €11.02 over the week versus €1.28 for the basic timer — a +759% uplift, projecting to roughly €502 per year for a single 10 kWh battery cycled once per day.
Average temperature was 17.9°C, with 45 hours of strong sunshine (solar ≥ 200 W/m²), average wind 6.3 km/h, and 15.9 mm of rainfall over the week.
Solar irradiance and spot price correlated at r=-0.66 (solar lowers prices), wind at r=+0.14 (wind raises 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 |
|---|---|---|---|---|
| 2026-09-11 | €0.00 | €0.00 | 0.0 ct/kWh | 12°C · ☀ 0 W/m² · 💨 3 km/h |
| 2026-09-12 | €1.72 | €0.12 | 19.1 ct/kWh | 16°C · ☀ 675 W/m² · 💨 5 km/h |
| 2026-09-13 | €1.37 | €0.39 | 15.2 ct/kWh | 17°C · ☀ 487 W/m² · 💨 7 km/h |
| 2026-09-14 | €2.37 | €0.67 | 26.3 ct/kWh | 18°C · ☀ 188 W/m² · 💨 9 km/h |
| 2026-09-15 | €1.67 | €-0.03 | 18.5 ct/kWh | 19°C · ☀ 676 W/m² · 💨 3 km/h |
| 2026-09-16 | €1.22 | €0.05 | 13.6 ct/kWh | 20°C · ☀ 640 W/m² · 💨 7 km/h |
| 2026-09-17 | €0.80 | €0.12 | 8.9 ct/kWh | 17°C · ☀ 263 W/m² · 💨 9 km/h |
| 2026-09-18 | €1.88 | €-0.03 | 20.9 ct/kWh | 18°C · ☀ 641 W/m² · 💨 5 km/h |
Want this kind of analysis on your own battery fleet? Get in touch.