Solar cost per watt: the fairest way to compare quotes
Total installed price ÷ system DC watts. Lets you compare quotes of different sizes. Typical U.S. quotes: about $2.50–$3.75/W before incentives.
Divide the price before incentives by the system’s DC watts (a $21,000 quote for 7 kW is $3.00/W). Include everything in the price: panels, inverters, permits, electrical upgrades.
Per-watt prices are higher for small systems and for complex roofs, and batteries should be compared separately (per usable kWh).
What this means for you: Ask every installer for price before incentives, DC system size, and first-year kWh — then compare $/W and ¢/kWh.