Why Getting Multiple Quotes Is Essential

Solar installations are a significant investment — typically tens of thousands of dollars before incentives. Yet many homeowners accept the first quote they receive, or choose based on price alone without understanding what they're actually comparing. A few hours of careful review can save you thousands and ensure you get a system that performs as promised for decades.

Here are the seven most important things to scrutinize before signing any solar contract.

1. Cost Per Watt — Not Just Total Price

Quotes will show different system sizes, making raw price comparisons misleading. Always convert to cost per watt ($/W) by dividing the total price by the system's total wattage. This lets you compare the true value of each proposal. If one quote is offering a dramatically lower $/W, dig into why — it may reflect cheaper equipment or a smaller system that won't fully meet your needs.

2. Panel Brand, Model, and Efficiency Rating

Not all solar panels are equal. Make sure each quote specifies:

  • The manufacturer and model number of the panels
  • The wattage per panel (e.g., 400W vs. 380W)
  • The efficiency percentage
  • The temperature coefficient (how much efficiency drops in heat)
  • The product warranty (typically 10–12 years) and performance warranty (typically 25 years, guaranteeing a minimum output level)

A quote using a tier-1 panel with a 25-year performance warranty is not the same as one using a lesser-known brand with a 10-year warranty, even if the system wattage is identical.

3. Inverter Type and Brand

The inverter converts your panels' DC power to usable AC power. There are three main types:

  • String inverters: Most affordable; one unit for the whole system. Performance is limited by the weakest panel.
  • Power optimizers + string inverter: Optimizes each panel individually; good for partially shaded roofs.
  • Microinverters: Each panel has its own inverter; best performance and monitoring, but higher cost.

Check the inverter brand reputation and warranty (typically 10–12 years for string inverters, 25 years for microinverters from leading brands).

4. Estimated Annual Production (kWh)

Each quote should include an estimated annual energy production figure in kilowatt-hours (kWh). Compare this to your current annual electricity consumption (found on your utility bills). A quality installer uses your actual roof orientation, local weather data, and shading analysis — not just a generic formula — to generate this estimate.

Red flag: If the estimated production seems unusually high, the installer may be over-promising to win your business. Ask them to explain their methodology.

5. Installer Credentials and Experience

Price and equipment aside, the installer matters enormously. Check:

  • State licensing: Verify the company holds the required electrical and contractor licenses in your state.
  • NABCEP certification: The North American Board of Certified Energy Practitioners (NABCEP) is the gold standard for solar installer certification.
  • Years in business: A company with a strong local track record is less likely to disappear before honoring warranty claims.
  • Insurance: General liability and worker's compensation insurance protects you if something goes wrong on your roof.

6. Workmanship Warranty

Separate from equipment warranties, the workmanship warranty covers defects in the installation itself — things like roof leaks caused by improper mounting or wiring issues. Industry standard is at least 10 years. Some installers offer 25 years. Be wary of companies offering only 1–2 years on their own work.

7. What's Included (and What Isn't)

Solar quotes sometimes exclude costs that will eventually appear on your final bill. Make sure you understand whether the quote includes:

  • Permit and inspection fees
  • Electrical panel upgrades (if your current panel needs it)
  • Roof reinforcement (if required)
  • Utility interconnection fees
  • System monitoring equipment and software

Ask every installer to provide an all-in, itemized quote so you can be confident you're comparing the same scope of work.

Final Advice

Get a minimum of three quotes from licensed, established local installers. Don't choose purely on price — the cheapest quote often reflects cheaper equipment, less experienced crews, or shorter warranties. The goal is the best long-term value, not just the lowest number on page one.