How to Choose a Solar Installer

2. How Many Installations Have You Completed in My Area?

Local experience has practical value. An installer who has worked in your county knows how the local permit office and utility handle applications, which documentation they require, and which roof types are common. That usually means fewer delays and fewer surprises.

Ask for references from at least three recent customers nearby and call them. Two questions matter most: Did the system go live on the timeline you were quoted? Is it producing about what the installer projected? Hesitation on either answer tells you something.

Ask every installer for a production estimate and the assumptions behind it. The standard tool is NREL’s PVWatts calculator; a competent installer can show you the report, including roof tilt, orientation and shading inputs. Cross-check the proposed system size against your actual annual electricity use with the solar system size calculator. For a price breakdown by system size and region, see our guide to How Much Do Solar Panels Cost in 2026?.

Local requirements also differ by state. Coastal areas such as Florida have wind-related building requirements that affect racking and attachment, and state incentive programs such as the SMART program in Massachusetts have their own paperwork. Ask whether the installer has completed projects under the rules that apply to you.

4. Does Your Quote Include Permitting, Interconnection and Utility Approval?

A complete quote should itemize equipment, labor, roof work, any electrical panel upgrade, permit fees, the utility interconnection application and inspections. Some low quotes leave out items that appear as extra charges after signing, so ask directly: “Is this quote turnkey, with all permits closed and the system approved to operate, for this exact price?” If not, ask what could change the price and get estimates in writing.

Electrical panel capacity deserves a specific question. If your home’s main panel cannot support the new system (or a future EV charger), an upgrade may be required. Ask whether your panel is adequate and have the answer written into the quote. Programs such as NY-Sun in New York also add documentation steps, which a reputable installer will already have built into the process.

When comparing quotes, divide each total by system size in watts to get a price per watt. Berkeley Lab’s data show how wide the spread can be.

Chart summary: Among the 100 largest residential installers, median prices in 2024 ran from about $2.7 to $6.5 per watt. Multiplying by 8,000 W (an illustrative calculation, not a quote), the same 8 kW system would cost roughly $21,600 at the low end and $52,000 at the high end, before incentives. The all-systems median was $4.00 per watt, and cash purchases were lower at $3.50. The bars measure different things (installer medians versus system medians), so read them as a range, not a ranking. Collect at least three itemized quotes and compare them per watt.

NREL research on quote data (2017) also found that large installers’ quotes averaged about $0.33 per watt higher than smaller installers’ quotes to the same customers. That data is older, so treat it as a reason to include both types in your comparison, not as a rule.

6. Which Incentives Still Apply — and What Happened to the Federal Tax Credit?

This is where outdated information causes the most confusion. Under the One Big Beautiful Bill Act, signed July 4, 2025, the 30% Residential Clean Energy Credit (Section 25D) ended for expenditures made after December 31, 2025. Homeowners who bought and installed a system by that date can still claim it on their 2025 return, and unused credit may carry forward. Homeowners who buy a system in 2026 get no federal credit.

Third-party-owned systems (leases and PPAs) are treated differently. The company that owns the system may still claim the commercial Section 48E credit if it meets the law’s deadlines and other requirements. Generally, projects needed to begin construction by July 4, 2026, or be placed in service by December 31, 2027. Any savings passed on to you depend on the contract, so ask how the rate reflects it. See our federal solar tax credit guide for updates, and consult a tax professional about your situation.

State and utility incentives vary and change often. Check the DSIRE database (dsireusa.org) and your utility’s website, and ask each installer: “Which incentives have you applied to this quote, and what documentation will you give me to claim them?” If a quote for a system you will own still assumes a 30% federal credit, that is a sign the installer is using outdated information, or worse, misleading you.

A knowledgeable installer should be able to name the programs available in your area and explain how net metering or similar rules affect your savings. That level of detail separates a true expert from a high-volume sales operation.