Loss calculator
Enter the plant parameters. We calculate how much it loses against the investment model and how much active management recovers.
This year your plant will lose
- Lost since commissioning
- Loss to end of life
- With active management you save up to
30 years of operation
Where you lose this year
Loss over 30 years by management
Your scenario is highlighted.
Year by year
How we calculate
The calculation uses the reference plant model from the study Solar PV Underperformance 2026 (sections 6 and 24). The individual losses are not added but multiplied, because they act on the same energy: output = capacity × yield per 1 kWp × (1 − degradation)year − 1 × (1 − availability) × (1 − soiling) × (1 − unresolved faults).
The model does not include a one-off outage for inverter replacement in year 13, so the curve does not jump. In reality such an outage can happen, and for a neglected plant it is usually the longest.
The loss is the difference against the investment model, which usually assumes only natural degradation of 0.5% a year.
| Parameter | Active | Occasional | Unmonitored |
|---|---|---|---|
| Annual degradation | 0,50 % | 0,65 % | 0,80 % |
| Availability loss | 1,0 % | 2,3 % | 5,0 % |
| Soiling loss | 1,0 % | 2,0 % | 3,0 % |
| Unresolved faults | up to 3% | rises to 7%, then 9% | rises to 8, 14 and 18% |
The model is deterministic and works with averages. A real plant behaves in steps and faults occur at random. The Unmonitored scenario is an extrapolation. The energy price stays the same throughout, with no inflation or discounting. The saving with active management is the difference between model scenarios, not a guarantee. The conservative estimate assumes up to 4 percentage points of annual output, which matches the difference between plants with one and five inspections a year (Raptor Maps 2026).
Want the calculation based on your actual data? We will compare the model with what the plant really produces.
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