Clear answer, explained.
A performance review starts with production data analysis — comparing actual monthly or annual generation against the modelled output from the project's original financial analysis, accounting for local weather variation. Any sustained gap between actual and modelled production is then mapped against potential causes: shading changes, inverter logs, string monitoring data, and visual inspection.
The physical inspection component covers panel condition, racking and mounting hardware, electrical connections, combiner boxes, inverter condition, and monitoring system accuracy. Where thermographic imaging has not been conducted recently, it is typically added to the review scope to identify module-level hotspots not visible in production data. Where monitoring is absent or inadequate, the review also establishes a monitoring baseline for ongoing tracking.
Cost depends on system size and complexity but is typically in the range of a few thousand dollars for a standard commercial installation — a fraction of the annual electricity savings at stake if a fault has been silently reducing output for months or years. Performance reviews are particularly recommended for systems more than three to five years old without recent O&M, for systems acquired as part of a property transaction, and for any system where production data suggests a shortfall.
What this means in practice.
- Production data analysis: actual vs modelled generation
- Physical inspection: panels, wiring, inverters, mounting hardware
- Thermographic imaging typically included if not recently conducted
- Monitoring assessment and baseline establishment if monitoring is absent
- Cost: typically a few thousand dollars depending on system size
- Recovers cumulative financial loss from undetected faults
Best-fit environments.
- Systems 3–5+ years old without established O&M programme
- Property acquisitions including rooftop solar in the purchase
