Start with the exact model code
A product family can contain several wattages and electrical variants. Match the model code on the quote to the exact row in the current datasheet before comparing numbers.
Read voltage and current as a set
Maximum-power voltage (Vmp) and current (Imp) describe operation near the module’s maximum-power point. Open-circuit voltage (Voc) and short-circuit current (Isc) matter for array design and inverter/controller limits. String design must account for temperature, not only standard-test-condition values.
Check dimensions, weight and mechanical ratings
Module size and mass affect roof layout and handling. Mechanical-load ratings, frame details and approved mounting zones should be checked against the current installation manual and local structural requirements.
Separate module efficiency from system output
Efficiency describes how effectively a module converts irradiance over its area under defined conditions. Real energy yield also depends on orientation, shading, temperature, inverter behavior, soiling, wiring and local weather.
Read warranty language carefully
Product workmanship warranties and performance warranties are different. Check duration, degradation assumptions, exclusions, claim process and who is responsible for labor or transport.
Use the solar panel guide and bifacial site checklist for the next step.