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Solar Panel Brand Comparator

Compare up to 3 solar panel models side by side — cost per watt, efficiency, 25-year production value, and more.

Shared Inputs
hrs
$/kWh
Panel 1
W
%
$
yrs
Panel 2
W
%
$
yrs
Panel 3
W
%
$
yrs

How to Compare Solar Panels

Cost Per Watt — The Most Useful Metric

Dividing panel cost by wattage gives you cost per watt ($/W), the standard unit for comparing solar value. Lower is generally better, but efficiency and warranty also matter significantly. A premium panel at $0.90/W may outperform a budget option at $0.70/W over 25 years if it has higher efficiency and a better degradation warranty.

Efficiency Matters for Space-Constrained Roofs

Higher efficiency panels produce more power from the same roof area. If your roof space is limited, paying more for high-efficiency panels (21%+) can mean more total system capacity. If space is abundant, standard efficiency panels at lower cost per watt may be the better value.

Temperature Coefficient

All solar panels lose efficiency as temperature rises. The temperature coefficient tells you how much power drops per degree Celsius above 25°C. A coefficient of -0.26%/°C loses far less power on hot days than -0.40%/°C — important in hot climates like Arizona, Texas, or Florida.

Warranty — The Long Game

Most premium panels offer a 25-year linear power warranty guaranteeing at least 80-92% output at year 25. Budget panels may guarantee only 80% at 25 years vs. 92% for premium brands — a 12% difference in lifetime production. Always compare the power warranty degradation rate, not just the warranty length.