Advanced tool

Advanced solar diagnosis

Enter your annual production history to get a higher-confidence diagnosis. More data = more accurate results.

System size (kW)

Location

Inverter brand (optional)

Enter your system's annual production for each year, starting from the most recent. More years = higher confidence.

2026kWh

2025kWh

2024kWh

2023kWh

2022kWh

No data is stored. All calculations happen in your browser.

Based on conservative solar performance modelling and published degradation data

NRELIEA-PVPSSunSpecPVsyst+ published research

Updated June 2026 · Structured performance modelling