How to Read a Solar Quote (So You Don't Overpay or Get Burned)

Every solar salesperson knows how to make their number look good. One quote leads with a low monthly payment. Another leads with a lifetime-savings chart that only works if your electric bill rises 5% a year forever. Neither one puts the figure that actually matters where you can see it.

You do not have to be an engineer to read a solar proposal. You just need to know which numbers to pull out and compare, and which gaps mean the installer left something out on purpose.

The one number that makes quotes comparable: price per watt

Two proposals for the same roof can quote different system sizes and look completely unlike each other. The figure that puts them on the same scale is cost per watt installed.

Take the gross (total contract) price, divide it by the system size in watts:

$28,500 / 9,500 W = $3.00/W installed

This single step normalizes for system size, so you can compare a 7 kW quote against a 11 kW quote on a level field. A cheaper quote for a smaller system is not automatically the better deal. Price per watt is the only apples-to-apples comparison across differently sized proposals.

For 2026, national installed cost benchmarks (from Lawrence Berkeley National Laboratory's "Tracking the Sun" and EnergySage market data) land roughly here:

• Budget tier (Chinese panels, basic string inverter): about $2.40 to $2.70/W
• Mid-tier (Qcells, Canadian Solar, TOPCon): about $2.70 to $3.20/W
• Premium tier (SunPower Maxeon, REC Alpha Pure, Panasonic EverVolt): about $3.20 to $4.50/W or more

High-cost markets (California, New York, Hawaii) run 15% to 30% above the national average. Lower-cost markets (Texas, Florida, Arizona) run 5% to 15% below. Use your region, not the national midpoint, as your benchmark.

The five line items a real quote always names

A complete, honest proposal states all of these. If one is missing, that is your first question back to the installer, and the answer tells you a lot.

1. Panel brand and model, not just brand. "SunPower panels" is not a specification. "SunPower Maxeon 7, SPR-MAX7-440W" is a model you can look up. Ask for the data sheet and confirm rated efficiency, the output guaranteed at year 25 or 30 (typically 87% to 92% for quality brands), and the temperature coefficient.

2. Inverter type. The three options are a basic string inverter, a string inverter plus power optimizers (SolarEdge, Tigo, roughly $300 to $900 more), or microinverters (Enphase IQ8, APsystems, roughly $500 to $1,500 more). Microinverters and optimizers give per-panel monitoring and better shade tolerance. If you have a shaded or multi-orientation roof and the quote only proposes a bare string inverter, push back.

3. Annual production in kWh. This is the number that should track your actual usage. If one estimate for the same roof is 15% higher than the others, ask why. Ask which software modeled it (NREL PVWatts, Aurora Solar, Helioscope are industry standard) and what derate factor was applied. The standard NREL derate is 0.86, meaning 86% of lab output. Anything above about 0.92 is optimistic.

4. Warranties, all three. Panels carry a product warranty (manufacturing defects) and a separate performance warranty (the guaranteed % of output at year 25). Inverters carry 10 to 25 years depending on type. The third one homeowners forget is the installer's workmanship warranty, covering roof penetrations, wiring, and installation quality. A 2-year workmanship warranty from a company that might not be around in 5 years is worth almost nothing.

5. Permit included. Solar installs require a permit in every U.S. jurisdiction, and the permit triggers the inspections that verify safe electrical work and structural attachment. A quote that excludes the permit looks cheaper, but you end up either doing the permit yourself or accepting unpermitted work, a liability at resale and with insurance. Ask directly: "Is the permit included, and will you pull it with the local authority having jurisdiction?"

The red flags that mean stop and re-read

• A price that expires today. Real installation prices do not vanish overnight. Manufactured urgency is the oldest close in the book.
• A monthly payment with no total price. If you cannot find the contract total, you cannot compute price per watt, which is usually the point of hiding it.
• Unnamed equipment. "Tier 1 panels" is marketing, not a model number you can verify.
• A savings chart built on 5%+ annual rate increases, every year, forever. Rates do rise, but a projection that needs that to work is selling you the chart, not the system.
• A production estimate above 95% of lab output. That is an inflated number making the payback look better than reality.
• No production guarantee. A reputable installer commits to annual kWh production and often includes a mechanism to address chronic underperformance.
• Price below $2.00/W. It typically means no permit, cheap substituted hardware, or hidden fees.
• Pressure to sign on the first visit. A fair quote survives a week of thinking.

How to compare three quotes side by side

Get at least three itemized quotes, then line up the same yardsticks for each:

• Price per watt (gross price divided by system watts)
• Annual production (kWh)
• Production per dollar (annual kWh divided by contract price, which catches quotes that look cheap but produce little)
• Escalator (for leases or PPAs, the annual payment increase; treat anything above 3% skeptically, because it compounds over 25 years)
• Warranty years, especially the roof-penetration coverage

Ask each installer to itemize equipment, labor, and permitting, because line items make padding visible. And ask why their production estimate differs from the others, because it tells you who actually modeled your roof and who did not.

One warning on reputation: the lowest price from a company that may not exist in year five is not the lowest price. Warranty service requires someone to answer the phone in year twenty. Verify the state license, the local crews, and reviews that mention service after installation.

And a note on incentives: the 25D federal residential solar credit ended for homeowner purchases made after December 31, 2025. In 2026 your deal is built on what survives, which is usually state rebates or tax credits, net metering or export credits, and the hardware and workmanship warranties above. Build the math on those, not on a federal credit that is no longer available to you.

Start with the facts about your roof

Before you let three salespeople walk into your driveway, you deserve the address-specific numbers that frame the whole conversation: how much sun your actual roof catches, how many panels it can realistically hold, what system size fits, and what that is worth in your specific utility market. That is not a sales estimate and it is not a hard-sell call. It is a report.

Scan your address at https://solrscan.com for $19 and get your sunshine hours, recommended panel count and wattage, estimated system size and install cost, and projected energy savings. Walk into every quote already knowing your roof's numbers, so you are comparing installers against reality instead of guessing which pitch sounds best.

Sources

• ElectrifyCalc, "How to Read and Compare Solar Quotes in 2026" (benchmarks from LBNL Tracking the Sun and EnergySage 2026 market data)
• EcoGen America, "How to Read a Solar Quote: Red Flags and What to Compare"
• U.S. Department of Energy, Homeowner's Guide to Solar
• Lawrence Berkeley National Laboratory, Tracking the Sun
• NREL, PVWatts Production Estimation Methodology