Daily guide · IT-SUD · 2026-08-13
What a home battery earned in Italy South this week, hour by hour
All numbers computed from the week's published auction results at publication and frozen — this article is an honest snapshot, not a page that rewrites itself. Reproduce via the API.
A single 10 kWh cycle in Italy South earned between 0,50 and 1,26 EUR this week, with the strongest days being 10 August at 1,26 EUR and 9 August at 1,20 EUR. Both leaned on the same pattern: charge in the cheap midday window and discharge into the evening peak. On 9 August the cheap average fell to 72,23 EUR/MWh while the peak reached 213,88 EUR/MWh, the widest gap of the week; 10 August paired a 138,94 EUR/MWh trough with a 294,41 EUR/MWh peak.
The weaker days, 8 August at 0,50 EUR and 7 August at 0,55 EUR, came when peaks stayed near 211 to 240 EUR/MWh and troughs held above 139 EUR/MWh. The average spread across the week was 112,71 EUR/MWh, with a round-trip efficiency of 90 percent assumed.
For the reader the takeaway is timing. The cheap window sat mostly around 11:00 to 13:00 and the peak around 19:00 to 20:00. Total weekly value was 6,13 EUR, consistent with roughly 320 EUR annually on this hardware.
A home battery makes money on one thing: the gap between the day's cheapest and priciest hours. Charge low, discharge across the evening peak instead of buying it, repeat daily. The size of that gap is set every afternoon at the day-ahead auction — so it's measurable, not hypothetical. Here is what one full daily cycle of a 10 kWh battery (at 90% round-trip efficiency — losses included, unlike most brochures) would have captured in IT-SUD this week.
€6.13
captured this week — one cycle per day, wholesale component, after losses
112.71
€/MWh average cheapest-2h → priciest-2h spread this week
≈€320
a year at this week's spreads — the honest run-rate, not the best-day fantasy
Day by day: the two windows that mattered
| Day | Charge (2h) | at €/MWh | Discharge (2h) | at €/MWh | Cycle value |
|---|---|---|---|---|---|
| 2026-08-06 | 11:00–13:00 | 162 | 20:00–22:00 | 283.25 | €0.93 |
| 2026-08-07 | 12:00–14:00 | 160.52 | 19:00–21:00 | 239.77 | €0.55 |
| 2026-08-08 | 13:00–15:00 | 139.48 | 19:00–21:00 | 211.07 | €0.5 |
| 2026-08-09 | 11:00–13:00 | 72.23 | 22:00–24:00 | 213.88 | €1.2 |
| 2026-08-10 | 11:00–13:00 | 138.94 | 20:00–22:00 | 294.41 | €1.26 |
| 2026-08-11 | 10:00–12:00 | 143.54 | 19:00–21:00 | 252.15 | €0.83 |
| 2026-08-12 | 15:00–17:00 | 144.98 | 19:00–21:00 | 256.11 | €0.86 |
Local time, hourly auction means. Days where charging was negative-priced mean you were paid to fill the battery.
Do it automatically
The windows move every day — automation is the whole game. One API call returns a cost-optimal schedule your inverter or energy manager can follow, and there's a full battery simulator to backtest your exact capacity, power and cycle limits against realized prices before you trust it:
curl -X POST -H "Authorization: Bearer YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"zone": "IT-SUD", "capacity_kwh": 10, "max_power_kw": 5,
"round_trip_efficiency": 0.9, "max_cycles_per_day": 1}' \
https://voltcast.com/api/v1/optimize/batteryHome Assistant users get the schedule as a sensor via the integration. And because the value depends entirely on tomorrow's spread, the P10–P90 forecast — scored publicly every day — tells you whether tomorrow is worth a deep cycle at all.
Method & citation. Prices are hourly means of published day-ahead auction results (native 15-minute periods averaged; ENTSO-E/SMARD, attributed). Wholesale-price component only — grid fees and taxes come on top and vary by supplier. Cite as "Voltcast Research, voltcast.com/guides/battery-arbitrage-it-sud-2026-08-13".
The monthly European power roundup
Negative-price records, the biggest spreads, which zones were hardest to forecast — every number computed from our production data, on the 2nd of each month. No filler, unsubscribe anytime.