Clear answer
Clear answer, explained.
Common causes: inverter faults (identifiable from monitoring data), panel soiling or physical damage, shading from new obstructions, wiring or connection degradation, or inverter efficiency loss in older units. A site inspection typically identifies the cause within one visit.
Key points
What this means in practice.
- Compare actual generation to the original production model using monitoring data — not just a gut feeling
- A 5–10% variance is within normal range for seasonal and weather variation
- A sustained gap larger than 5–10% across multiple months or an annual total warrants investigation
- Common causes: inverter faults, panel soiling or physical damage, shading from new obstructions, wiring degradation
- Inverter faults are typically identifiable from monitoring data before a site visit
- A site inspection typically identifies the cause within one visit
When this applies
Best-fit environments.
- Your solar system's generation appears lower than expected and you want to determine whether it warrants investigation
- You have monitoring data showing a sustained generation gap and want to understand the likely causes
- You recently noticed new obstructions — construction, tree growth — near your solar system and want to assess impact
- Your inverter monitoring has shown fault alerts and you want to understand next steps
Q·01
