How to Compare Two Solar Quotes Side by Side (2026)

Two solar quotes almost never line up — different sizes, prices, and financing make them look impossible to compare. Here's the framework I use to make them apples-to-apples in about 20 minutes.

Two solar quotes almost never line up. One is for a 9.2 kW system, the other 7.8 kW. One shows a "cash price," the other a monthly payment. One brags about a 25-year warranty, the other about production. Side by side, they look like two different languages — which is exactly why it's so easy to pick the wrong one. I don't install anything, so I have no system to sell you. What I do is read both quotes and make them comparable. Here's the framework I use.

Step 1: Normalize everything to price-per-watt

This is the single most important move, and it takes one minute. Take the gross system price (before any financing, before any incentive) and divide it by the system size in watts. A 9.2 kW system is 9,200 watts. So a $27,600 system works out to $3.00 per watt as an example.

Do this for both quotes. Now the size difference disappears and you're comparing the actual rate you're paying for solar. As a directional gauge, installed residential pricing often lands somewhere around $2.50–$3.50 per watt, but that swings by region, equipment, and roof complexity — so treat it as a sniff test, not a verdict, and verify against your own quotes. If one quote is at $2.80 and the other is at $4.10, you now know exactly which conversation to have.

Step 2: Line up the equipment, not just the brand names

A higher price-per-watt isn't automatically a rip-off — sometimes you're paying for better gear. So compare the actual hardware:

  • Panels: wattage per panel, brand, and the panel-level warranty term.
  • Inverters: microinverters vs. a string inverter, and the warranty length on each.
  • Battery: is one quote including storage and the other not? That alone can explain a multi-thousand-dollar gap. Strip the battery out before you compare the rest.
  • Racking and roof work: any re-roofing, electrical panel upgrades, or trenching baked into one quote but not the other.

The goal is to find out whether you're comparing the same scope. A lot of the "huge price difference" cases I review turn out to be one quote quietly including something the other left out.

Step 3: Separate the price from the financing

This is where a lot of buyers get steered. A cash price and a loan are not the same number, even when the marketing makes them look identical. Many solar loans carry a dealer fee — a markup baked into the financed price to "buy down" the interest rate. It can quietly add a meaningful percentage to your total.

So always ask both installers for the cash price first, then the financed price, and compare those two against each other. If the financed number is a lot higher, the gap is your dealer fee. Compare loan-to-loan only when the cash prices and the loan terms (rate, length) actually match. Mixing a cash quote against a financed quote is comparing apples to a more expensive apple.

Step 4: Check the net-metering assumptions

Two installers can model the same roof and project very different savings, mostly because of what they assume about how your utility credits the power you export. Net-metering and successor tariff rules vary by state and utility, and they change — so don't take either proposal's savings math on faith.

Look at what rate each quote assumes you're paid for exported energy, and whether they assume full retail credit or something lower. If one quote's savings look rosier, it's often because it assumed a more generous export rate. Confirm the current terms directly with your utility or your state's public utility commission before you believe either number.

Step 5: Compare warranties term by term

"25-year warranty" means nothing until you know which 25 years. Line them up:

  • Equipment/product warranty on panels and inverters.
  • Workmanship/labor warranty — who pays to send a truck if something fails.
  • Roof penetration warranty — leaks around the mounts.
  • Production guarantee, if any, and the fine print on how it's measured.

A cheaper quote with a 10-year labor warranty can cost you more than a pricier one with 25 years of labor coverage, the first time a truck roll isn't free.

Step 6: Sanity-check the production estimates

If one quote claims your system will produce noticeably more energy per watt than the other on the same roof, ask why. Same location, same shading, similar panels should produce roughly the same per kilowatt. A suspiciously high production estimate makes the savings and payback look better than they'll actually be. Inflated production is one of the quieter ways a quote gets dressed up.

Step 7: One number to rule them all

After you've normalized everything, the cleanest comparison is total cost over the life of the system versus total estimated savings — but if you want a fast read, go back to price-per-watt for matched scope. Same equipment, same financing type, same net-metering assumption: now the lower price-per-watt is genuinely the better deal, and you can negotiate the higher one down or walk. One quick warning sign while you're at it — if a rep is still quoting you a "30% federal tax credit," they may be working from outdated information. The federal residential credit changed for 2026, so check the current rules and any state or local programs before you count on any incentive.

Want me to do this with you?

Lining up two quotes is the whole job, and it's the free second opinion I give. Here's where to start: