Daily guide · LV · 2026-08-10
What a home battery earned in Latvia 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.
The week split cleanly into two halves. From 3 to 5 August a 10 kWh battery cycling at 90 percent round-trip efficiency captured strong evening premiums: peak averages of 181,72, 152,58 and 155,48 EUR/MWh against cheap-window prices of 17,01, 28,70 and 20,21 EUR/MWh delivered daily cycle values of 1,47, 1,09 and 1,20 EUR. Then the spread collapsed. On 6, 7 and 8 August peaks fell to 53,91, 40,86 and 44,91 EUR/MWh, and cycle value dropped to 0,45, 0,35 and 0,40 EUR.
What stands out is that cheap-window prices near zero did not rescue those weaker days; on 8 August the trough averaged 0,56 EUR/MWh, yet the muted peak left only 0,40 EUR on the table. Arbitrage income depends on the spread, not on cheap charging alone. The week closed with 9 August recovering to a 128,31 EUR/MWh peak and 1,15 EUR of value.
Across the week the average spread was 98,04 EUR/MWh, total value 6,11 EUR, implying roughly 319 EUR annually. The takeaway: prioritise cycling on evenings when the peak is clearly elevated, and accept that flat-peak days rarely repay the effort.
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 LV this week.
€6.11
captured this week — one cycle per day, wholesale component, after losses
98.04
€/MWh average cheapest-2h → priciest-2h spread this week
≈€319
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 |
|---|---|---|---|---|---|
| 2026-08-03 | 14:00–16:00 | 17.01 | 20:00–22:00 | 181.72 | €1.47 |
| 2026-08-04 | 10:00–12:00 | 28.7 | 21:00–23:00 | 152.58 | €1.09 |
| 2026-08-05 | 15:00–17:00 | 20.21 | 20:00–22:00 | 155.48 | €1.2 |
| 2026-08-06 | 13:00–15:00 | 3.16 | 00:00–02:00 | 53.91 | €0.45 |
| 2026-08-07 | 03:00–05:00 | 1.82 | 21:00–23:00 | 40.86 | €0.35 |
| 2026-08-08 | 14:00–16:00 | 0.56 | 21:00–23:00 | 44.91 | €0.4 |
| 2026-08-09 | 14:00–16:00 | 0 | 20:00–22:00 | 128.31 | €1.15 |
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": "LV", "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-lv-2026-08-10".
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