Solar Panel Size Verification Checklist PDF

Full QC Checklist+

Verify energy usage input accuracy, peak sun hours/location accuracy, system sizing/panel selection, and roof/installation/code compliance.

✓21 Inspection Points

✓4 Verification Categories

✓Energy Usage Input Accuracy+

Actual average monthly usage confirmed from utility bills, not estimated
A representative average month used, not an unusually high or low outlier month
Reasonably foreseeable future loads (EV charger, pool, home addition) considered before finalizing the offset target
Seasonal usage variation considered, not assumed flat across the year
Usage figure confirmed to match the specific property/meter the system is being sized for

✓Peak Sun Hours & Location Accuracy+

Peak sun hours sourced for your specific location, not a generic or national average
Peak sun hours figure reflects an annual average, not a single best-case summer day
Shading from trees, buildings, or other obstructions considered separately from the system efficiency factor
Roof orientation and tilt confirmed reasonably close to optimal, or a lower efficiency factor used if not
Local climate/weather pattern (persistent cloud cover, monsoon season, heavy haze) reflected in the peak sun hours figure used

✓System Sizing & Panel Selection+

System efficiency/derate factor confirmed appropriate for your installation, not left at the generic default for an unusual setup
Panel wattage matches the actual product being considered, not a placeholder value
Panel efficiency used for the roof area calculation matches the actual panel technology's spec sheet
Solar offset target genuinely matches your actual goal — full offset, partial offset, or oversized for future growth
Understood that panel count rounds up to a whole number, so the actual array typically exceeds the bare minimum requirement

✓Roof, Installation & Code Compliance+

Actual usable, unobstructed roof area confirmed sufficient for the calculated panel count — not just the calculated area in the abstract
Roof structural capacity for panel weight, wind load, and snow load confirmed by a qualified professional
Local permitting, utility interconnection, and net-metering rules checked separately
Electrical integration (inverter capacity, service panel capacity) cross-checked separately
Battery/backup storage, if desired, sized separately — not modeled by this calculator
Licensed solar installer site assessment obtained before purchase or installation

Inspection Notes+

Use the latest approved drawings, specifications, and site measurements.

Complete all critical checks before proceeding to the next work stage.

Record deviations and confirm rectification where required.

Inspection Notes

Use the latest approved drawings, specifications, and site measurements.

Complete all critical checks before proceeding to the next work stage.

Record deviations and confirm rectification where required.

Use it after collecting the project inputs and again before approving or closing the relevant work stage.

No. It supports verification but does not replace approved drawings, specifications, codes, manufacturer requirements, or professional inspection.