Price per watt is the total installed price of a solar system before incentives divided by its size in watts of panel capacity. A quote of a given total for a given system size can be converted to dollars per watt, which lets you compare offers for systems of different sizes. Check that each quote includes the same things: permits, interconnection, monitoring, any electrical panel upgrade and the warranty terms. Dealer fees on financed systems are often built into the price and can make a loan-financed system look much more expensive per watt than a cash purchase. Berkeley Lab publishes the median price per watt by state each year; our state pages use it as a planning estimate, not as a quote.
Related terms and pages
- Dealer fee: A charge a solar lender takes from the installer, usually built into a financed system's price.
- Kilowatt (kW) vs. kilowatt-hour (kWh): kW measures power (system size); kWh measures energy (what you produce and use).
- Solar cost by state