Monthly production micro-inverter report — exact value
Monthly grid import (peak / off-peak) network operator meter
Monthly balance: production → self-consumption & surplus surplus = estimate
Estimated monthly gain and cumulative total
Yearly summary
| Prod. | Self | Surplus | Avoided | Resale | Total | |
|---|---|---|---|---|---|---|
| Year 1 Sept 2024 → Aug 2025 |
6498.1 | 4067.2 | 2431.0 | 858.18 € | 316.27 € | 1174.45 € |
| Year 2 Sept 2025 → Aug 2026 (partial) |
5963.1 | 3505.1 | 2457.8 | 739.58 € | 319.76 € | 1059.34 € |
| Total | 12461.2 | 7572.3 | 4888.8 | 1597.76 € | 636.03 € | 2233.79 € |
Calculation method
Year 1: actual surplus = 2,431 kWh paid by the OA feed-in tariff (13.01 c€/kWh = 316.27 €).
Year 2: surplus estimated at ~2,458 kWh (Linky “active energy injected” register: 2457.9 kWh) — under the OA Tier-1 ceiling of 9,600 kWh/yr.
Gain = self-consumption × 0.211 € (peak) + surplus × 0.1301 €. Self-consumed energy replaces peak-hour grid purchases.
Self-consumption: “daily self-consumption baseline” model (13.54 kWh/day year 1, 12.44 kWh/day year 2) tuned to reproduce exactly the annual surpluses.
Last 12 complete months Aug 2025 → Jul 2026
Electric vehicle (V2C Trydan) VictoriaMetrics · since April 2025
Monthly EV charging: solar vs grid
Charging and solar share by hour (local, 6h–21h)
| Month | Charged kWh | Solar kWh | Solar share | Share of OA surplus |
|---|---|---|---|---|
| 04/2025 | 370 | 115.0 | 31.1% | 2.35% |
| 05/2025 | 200 | 129.0 | 64.5% | 2.64% |
| 06/2025 | 226 | 69.0 | 30.5% | 1.41% |
| 07/2025 | 195 | 37.0 | 19.0% | 0.76% |
| 08/2025 | 138 | 20.0 | 14.5% | 0.41% |
| 09/2025 | 171 | 45.0 | 26.3% | 0.92% |
| 10/2025 | 164 | 14.0 | 8.5% | 0.29% |
| 11/2025 | 352 | 8.0 | 2.3% | 0.16% |
| 12/2025 | 253 | 1.4 | 0.6% | 0.03% |
| 01/2026 | 168 | 0.3 | 0.2% | 0.01% |
| 02/2026 | 166 | 0.6 | 0.4% | 0.01% |
| 03/2026 | 39 | 19.0 | 48.7% | 0.39% |
| 04/2026 | 145 | 25.0 | 17.2% | 0.51% |
| 05/2026 | 76 | 28.0 | 36.8% | 0.57% |
| 06/2026 | 153 | 60.0 | 39.2% | 1.23% |
| 07/2026 | 130 | 7.0 | 5.4% | 0.14% |
| 08/2026 | 29 | 0.9 | 3.1% | 0.02% |
| Total | 2,975 | 579.2 | 19.5% | 11.8% |
Method and limitations
Data sourced from VictoriaMetrics (1-hour step, trapezoidal integration). sensor.evse_10_0_0_120_charge_power_value × 1 h gives hourly charging; min(charge_power, photovoltaic_power) × 1 h gives the solar share.
Important caveat: the VM exporter does not sample every minute; the 1 h step undercounts short bursts and days where the exporter delivered only one sample. Solar values are therefore a lower bound — the true share is likely a few points higher.
Charger: V2C Trydan, full solar mode (HA select mixed + dynamic intensity modulation), 16 A per phase (11 kW triphase). Night charging is entirely grid-fed (rare: 67 kWh over 17 months).
Before / after the installation
Average daily grid import
| Total import | Days | Avg/day | |
|---|---|---|---|
| Before (Sept 2023 → Aug 2024) | 15592.0 kWh | 366 | 42.6 kWh/j |
| After (Sept 2024 → 10 Aug 2026) | 26408.0 kWh | 709 | 37.2 kWh/j |
Comparison spans 12 months before (Sept 2023 → Aug 2024) vs ~23 months after install. Seasons are balanced; usage is unchanged (the EV charger was added in April 2025, so the “after” period includes some EV draw that was absent in the “before”).
Source: Enedis daily index readings (FOLDER_DAILY folder), trapezoidal interpolation between readings for boundaries.
Return on investment
Install cost: 13,000 € (all-in).
Estimated gain: ≈ 1174.45 €/yr (full year 1) and 1143.92 € over the last 12 months.
Payback period: 11.1 years (≈ 11.4 years on a rolling basis).
Standing charge unchanged: 30.59 €/month. All-in tariffs: peak 0.211 €, off-peak 0.1624 €.
Monthly consumption BEFORE solar
| Month | Peak kWh | Off-peak kWh | Total kWh | Days | kWh/day |
|---|---|---|---|---|---|
| Aug 2023 (18 → 31, partial) | 195 | 140 | 335 | 14 | 23.9 |
| 09/2023 | 534 | 338 | 872 | 30 | 29.1 |
| 10/2023 | 589 | 473 | 1062 | 31 | 34.3 |
| 11/2023 | 938 | 610 | 1548 | 30 | 51.6 |
| 12/2023 | 1106 | 750 | 1856 | 31 | 59.9 |
| 01/2024 | 1397 | 959 | 2356 | 31 | 76.0 |
| 02/2024 | 836 | 578 | 1414 | 29 | 48.8 |
| 03/2024 | 786 | 634 | 1420 | 31 | 45.8 |
| 04/2024 | 645 | 557 | 1202 | 30 | 40.1 |
| 05/2024 | 513 | 443 | 956 | 31 | 30.8 |
| 06/2024 | 501 | 445 | 946 | 30 | 31.5 |
| 07/2024 | 472 | 375 | 847 | 31 | 27.3 |
| 08/2024 | 346 | 267 | 613 | 31 | 19.8 |
| 12 months before solar | 8964.0 | 6628.0 | 15592.0 | 366 | 42.6 |
Methodological notes
- Production: official APS monthly report (total 12,461 kWh). The Home Assistant ECU counter shows 12330.5 kWh (≈ 1 % gap — meter reset / timestamp skew, APS values retained).
- Grid import: monthly readings from the network operator (exact). Peak/off-peak split by interpolation of the Enedis registers (monthly approximation).
- Surplus: Year 1 exact (OA invoice, 2,431 kWh), Year 2 estimated via the Linky “active energy injected” register. Monthly self-consumption is an estimate.
- Self-consumption is valued at the peak tariff under the assumption that solar mainly replaces daytime (peak) consumption.
- Tariffs and economic result vary with the contract; page generated on "17/08/2026".