Loss calculator
How much your solar plant loses against the investment model, and how much of that active management wins back. Calculated according to the Solar PV Underperformance 2026 study.
30 years of operation
The vertical line marks the current year. The blue area is the output that active management can win back. Hover over the chart to see the values for each year.
Where you are losing this year and how we help
Management scenarios compared
How much the plant loses over 30 years depending on how it is managed. The highlighted row is your scenario.
Year by year
Values from the model. The highlighted row is the current year.
How we calculate
The calculation uses the reference plant model from the Solar PV Underperformance 2026 study (sections 6 and 24). The individual losses are not added up but multiplied, because they act on the same energy: output = capacity × output per kWp × (1 − degradation)year − 1 × (1 − availability loss) × (1 − soiling) × (1 − unresolved faults).
The model leaves out the one-off outage during the inverter replacement in year 13, so that the curve does not jump. In reality, such an outage can happen, and at a neglected plant it tends to last longest.
The loss is the difference from the investment model, which usually assumes only natural degradation of 0.5% a year.
| Parameter | Active | Occasional | No oversight |
|---|---|---|---|
| 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 | 3% at most | 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 ‘No oversight’ 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 at most 4 percentage points of annual output, which corresponds to the gap between plants with one and with five inspections a year (Raptor Maps 2026).
Source: Solar PV Underperformance 2026 study · PDF
Want the calculation based on your real data?
We will compare the model with what your plant actually produces.