Solar Installation Checklist 6 Things to Verify Be

I got a call from a guy named Paul last spring. He had just signed a solar contract. Twenty‑four panels, 8.4 kilowatts, $32,000 before incentives. He was excited until he talked to his neighbor, who had a similar house and paid $24,000 for the same sized system. Paul wanted to know if he could cancel his contract. He couldn’t. The cancellation penalty was $1,500. He felt sick. I felt bad for him. He had signed the first proposal he received, from a door‑knocker who promised the world. He didn’t check anything.

Solar is a great investment for many homeowners. But only if you get a fair price, a quality installer, and the right equipment for your roof. I’ve audited over 1,200 homes, and I’ve seen the good, the bad, and the ugly of solar installations. Here are the six things you need to verify before you sign anything.

Number one: the price per watt. This is the most basic metric. Take the total system cost before incentives and divide by the system size in watts. For an 8.4 kilowatt system, that’s 8,400 watts. $24,000 divided by 8,400 is $2.86 per watt. That’s a good price in 2026. $32,000 divided by 8,400 is $3.81 per watt. That’s too high. In most of the U.S., a fair price is between $2.50 and $3.20 per watt before incentives. If a quote is above $3.50, get another quote. If it’s below $2.50, be suspicious of cheap equipment.

Paul paid $3.81. He overpaid by about $8,000. That’s why you always compare at least three quotes.

Number two: the equipment brand and warranty. Not all solar panels are the same. The top tier brands are REC, Panasonic, Qcells, and SunPower. Avoid no‑name panels from Chinese manufacturers you’ve never heard of. The warranty should be at least 25 years for performance and 12 years for product. Inverters are the weak point. String inverters last 10‑15 years. Microinverters and optimizers last 20‑25 years. Make sure the installer offers a workmanship warranty of at least 10 years.

I had a client who bought cheap panels from a door‑knocker. Two years later, one panel failed. The installer was out of business. He couldn’t find anyone to honor the warranty. He ended up paying $1,200 to replace it himself.

Number three: the production estimate. Installers use software like Aurora or Helioscope to estimate how many kilowatt‑hours your system will produce each year. Ask for that report. Check if they accounted for shading, roof orientation, pitch, and local weather. A reputable installer will guarantee the production estimate within 5‑10%. If they won’t guarantee it, or if the estimate seems too high, be careful. A typical 8.4 kW system in Denver produces about 12,000 kWh per year. If an installer says 15,000, that’s unrealistic.

You can check your own roof using NREL’s PVWatts tool. It’s free. Enter your address, roof tilt, and azimuth. It gives you a rough estimate. Compare that to the installer’s number.

Number four: the contract terms. Read the fine print. Look for the cancellation policy. Most states give you a three‑day right to rescind. But after that, you may be locked in. The contract should clearly state the total cost, the equipment list, the production guarantee, and the timeline. Watch out for “escalation clauses” in lease or PPA agreements. Some contracts raise the price you pay per kWh by 2‑3% every year. That can eat up your savings.

Also check who owns the renewable energy credits, or RECs. Those are environmental attributes. If the installer keeps them, they’re making extra money off your roof. You should own them or get a discount.

Number five: the installer’s reputation. Don’t just rely on Google reviews. Check with your state’s contractor licensing board. See if there are complaints. Ask for references from recent installs in your area. Visit a job site if you can. A good installer will be happy to show you their work.

Paul’s installer had great online reviews. But when I dug deeper, most of the reviews were from the same month, all five stars, all written in similar language. Fake. The company had been in business for only two years. They had no track record. That’s a red flag.

Number six: your utility’s net metering policy. This is the one that changes the math completely. Before you sign anything, call your utility or look up their net metering tariff. Ask these questions: Is it 1:1 net metering? Or is it net billing with separate import and export rates? Is there a monthly fixed charge that solar can’t offset? Is there a demand charge or minimum bill? Are there caps on system size?

In California under NEM 3.0, a solar system without a battery might take 15‑20 years to pay back. In Colorado with 1:1 net metering, payback is 8‑12 years. Same panels, different utility rules. If you don’t understand your net metering, you can’t calculate your true savings.

I had a client in Florida who signed a solar contract assuming 1:1 net metering. After installation, he learned that his utility only credited him at the wholesale rate, about $0.04 per kWh, while charging him $0.14 per kWh for imports. His payback went from 9 years to 22. He was furious. But he had already signed.

Don’t be that person.

Let me tell you about a client who did it right. Her name is Linda. She got four quotes. The prices ranged from $2.71 to $3.45 per watt. She chose the second lowest because the company had the best warranty. She checked the equipment: REC panels with Enphase microinverters, both 25‑year warranties. She ran her own production estimate using PVWatts. The installer’s estimate was within 3%. She read the contract line by line and negotiated a lower cancellation fee. She called her utility and confirmed the net metering terms were still 1:1. Then she signed.

Her system was installed six weeks later. It’s been producing exactly as predicted. Her electric bill went from $180 per month to $15 per month (the fixed customer charge). She expects payback in 10 years. She’s happy.

Linda spent about 20 hours on research. That’s the best investment she made.

Solar is a long‑term commitment. You’ll live with your system for 25 years. Rushing into a bad deal will cost you thousands. Take your time. Get multiple quotes. Verify everything.

I have tools that help with the math.

The Home Energy Bill Breakdown tool can help you understand your current usage before you size a system.

And for people in time‑of‑use territories, the Time‑of‑Use Rate Optimizer can show if adding a battery makes sense.