Optimising Home Battery Earnings — June 20 – 26, 2026

2026-06-27 — 10 kWh Battery, Vienna, EPEX Spot

Week Statistics

Optimal Strategy€14.68
Basic Timer€7.49
Weekly Uplift+€7.19
Annual Projection€670
Best Day2026-06-24
44.3 ct/kWh
Sunny Hours83 h

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: June 20 – 26, 2026.

The optimal strategy earned €14.68 over the week versus €7.49 for the basic timer — a +96% uplift, projecting to roughly €669 per year for a single 10 kWh battery cycled once per day.

Weather Impact

Average temperature was 28.1°C, with 83 hours of strong sunshine (solar ≥ 200 W/m²), average wind 6.4 km/h, and 10.5 mm of rainfall over the week.

Solar irradiance and spot price correlated at r=-0.54 (solar lowers prices), wind at r=-0.02 (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.

Daily Breakdown

DateOptimal StrategyBasic TimerSpreadWeather
2026-06-19€0.00€0.000.0 ct/kWh25°C · ☀ 0 W/m² · 💨 7 km/h
2026-06-20€1.42€0.4215.8 ct/kWh28°C · ☀ 825 W/m² · 💨 7 km/h
2026-06-21€1.31€0.2714.6 ct/kWh29°C · ☀ 862 W/m² · 💨 7 km/h
2026-06-22€1.63€0.7018.1 ct/kWh27°C · ☀ 777 W/m² · 💨 8 km/h
2026-06-23€3.01€1.9533.4 ct/kWh27°C · ☀ 811 W/m² · 💨 8 km/h
2026-06-24€3.98€2.7144.3 ct/kWh27°C · ☀ 875 W/m² · 💨 6 km/h
2026-06-25€1.47€0.4816.3 ct/kWh29°C · ☀ 825 W/m² · 💨 5 km/h
2026-06-26€1.86€0.9620.6 ct/kWh30°C · ☀ 863 W/m² · 💨 4 km/h
A €669/year uplift on a single 10 kWh battery is the kind of number that turns a long-payback installation into a sensible investment. The lever is software, not hardware — exactly the gap VoltShift is built to close.

Want this kind of analysis on your own battery fleet? Get in touch.