Solar Panel Cost Per Watt

Average Solar Cost Per Watt by State and Region

National averages smooth out differences that are really quite large. A homeowner in Arizona with strong sun and low permitting costs might lock in $2.55/W from a competitive local installer. A homeowner in Connecticut dealing with higher labour costs and a more complex utility interconnection process might see $3.20–$3.50/W as a normal range — drawing on SEIA and NREL regional benchmarks. For more on this topic, see our guide to Average Solar Panel Cost by State.

In the Southwest (Arizona, Nevada, New Mexico), realistic installed costs run $2.40–$2.80/W before incentives. The Southeast (Florida, Georgia, South Carolina) typically lands at $2.60–$3.00/W, while Texas comes in at $2.55–$2.95/W — its competitive installer market and streamlined permitting have kept prices below the national average. The Midwest (Illinois, Ohio, Michigan) ranges from $2.70–$3.20/W. The Pacific Coast (California, Oregon, Washington) averages $2.80–$3.40/W. The Northeast (New York, Massachusetts, Connecticut) runs $3.00–$3.60/W. Hawaii is the outlier at $3.20–$4.20/W, though its extremely high electricity rates mean the financial case for solar is still among the strongest in the country.

New York deserves a specific note: gross prices are above average, but the NY-Sun Megawatt Block incentive substantially reduces net cost. When you factor that in alongside the federal credit, New York homeowners often end up with effective net costs close to the national midpoint. The same logic applies in other high-price, high-incentive states — gross cost per watt is only half the story.

If you want to see the specific average cost, payback, and incentive data for your area, the state pages on this site cover all 50 markets in detail.

How to Read a Solar Quote and Spot Inflated Pricing

Most residential solar quotes arrive as a single total price with very little line-item detail. That opacity is not accidental. Getting a detailed breakdown — and knowing what to look for — is the most practical step you can take before signing a contract.

Ask for cost per watt explicitly. If an installer refuses to give you a per-watt figure, that’s a red flag. Any professional installer can calculate it in under a minute. The number should be clearly stated in writing before you proceed.

Check the panel wattage and count. A quote might list “20 panels” without specifying wattage. 20 × 400W panels is an 8 kW system. 20 × 350W panels is 7 kW — nearly 15% less capacity for the same panel count. Make sure the system size in kilowatts is explicitly stated, not implied.

Verify the production estimate. Quotes should include a first-year production estimate in kilowatt-hours (kWh). Divide that number by the system size in watts and you get expected hours of “peak sun equivalent” per day. For most continental US locations, this should land between 3.5 and 6.0. A production estimate implying 6+ hours of peak sun in a state like Ohio should be questioned — it may be inflated to make payback look shorter than it actually is.

Look at the warranty structure. Panels should carry a 25-year performance warranty guaranteeing at least 80% of rated output. The installer workmanship warranty should be at least 10 years; some reputable companies offer 25. Inverter warranties typically run 10–12 years for string inverters and 25 years for Enphase microinverters.

Compare financing terms carefully. Installer-arranged solar loans often carry interest rates of 5.99%–9.99% APR for terms of 10–25 years. The monthly payment looks manageable until you calculate total interest paid. A $20,000 system financed at 7.99% over 20 years costs $35,700 in total payments — $15,700 in interest on top of the principal. Use the solar loan calculator to model different loan terms and compare the true cost of financing against paying cash or using a home equity line.

Ask about post-installation support. Monitoring, maintenance, and interconnection handholding are areas where budget installers often cut corners. A system that isn’t properly commissioned or that goes unmonitored can underperform for months before anyone notices. Confirm what’s included in the installer’s service agreement beyond the warranty period itself.

Before you finalize any purchase decision, run your numbers through the solar savings calculator to confirm the projected savings align with what an installer is telling you — based on your actual roof size, electricity rate, and local sun hours.