1. Production estimates that look too good
If a proposal claims your system will produce 1,500+ kWh per kW per year in a state like Minnesota or Massachusetts, that's a red flag. Realistic annual production for most of the U.S. ranges from 1,100 to 1,500 kWh per kW. Inflated estimates make the payback math look better than reality. Always cross-check estimates against the free PVWatts calculator from NREL.
2. Vague or missing equipment specs
A real proposal lists exact panel make and model (e.g., "Qcells Q.PEAK DUO BLK ML-G10+ 400W"), exact inverter make and model, and total system size in kW DC. Phrases like "premium tier-1 panels" or "high-efficiency inverter" without model numbers are sales-speak, not specs.
3. Price-per-watt above $4.00 (cash)
The 2026 national average for residential solar is roughly $2.75–$3.50 per watt cash. Anything above $4.00/W needs serious justification — premium equipment, complex roof, or batteries included. We break this down in our cost-per-watt guide.
4. Escalator clauses on solar leases or PPAs
Many leases include a 2.9–3.9% annual price escalator — meaning your "savings" shrink every year. By year 20, your solar payment can exceed what you would have paid the utility. If you're considering a lease or PPA, demand a 0% escalator or run from the deal.
5. High-pressure "sign tonight" tactics
"This pricing is only good if you sign right now" is the oldest sales trick in the book. Legitimate solar pricing is good for at least 7–14 days. If a rep pressures you to sign during the first visit, they're protecting their commission, not your wallet.
6. Missing or incomplete shading analysis
A real solar proposal includes a shading report — typically a Solar Pathfinder, HelioScope, or Aurora analysis showing TSRF (Total Solar Resource Fraction) per panel. If shading isn't mentioned, the production estimate is probably based on a perfect roof and you'll under-produce.
7. 100% offset claims without battery
"This system will eliminate your electric bill" is rarely true without battery storage. Net metering rules vary by state, and most utilities still charge a monthly fixed connection fee ($10–$30) regardless of production. Read more in our offset guide.
8. No mention of interconnection or permitting timeline
From contract signing to PTO (Permission to Operate), most systems take 60–120 days. If a proposal promises "installed in 30 days" without explaining permits and utility approval, the salesperson either doesn't know or is misleading you.
9. Workmanship warranty under 10 years
Top installers offer 25-year workmanship warranties. A 5-year or 10-year workmanship warranty is a red flag — it usually means the installer plans to be out of business or unwilling to honor claims past that point.
10. "Free solar" or "$0 down forever" claims
There is no free solar. Every system is paid for somehow — through cash, loan interest, lease payments, or PPA energy charges. "$0 down" usually means a loan with a high interest rate (6.99–9.99%) or a lease with an escalator. Read more about predatory solar financing tactics.
11. ANY mention of a 30% federal tax credit on a 2026 cash or loan purchase
This is the biggest new red flag of 2026. The 30% federal Residential Clean Energy Credit (Section 25D) expired December 31, 2025. Homeowners who buy solar with cash or a loan in 2026 and beyond cannot claim it. If your proposal still subtracts a "30% federal credit" from the cost, the installer is either out of date or actively misleading you. The math is wrong, and the payback period in their proposal is wrong too.
The only way to indirectly benefit from a federal solar incentive in 2026 is through a third-party-owned system (lease or PPA), where the solar company claims the commercial ITC and may pass some savings through. See our federal tax credit guide for full details.
12. The contract doesn't match the proposal
Always compare the final contract line-by-line with the original proposal before signing. System size, panel model, inverter model, price, and warranty terms should all match exactly. If the contract is "missing details," request a revised contract — never sign a partial document.
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Analyze My Solar Bid →Frequently asked questions
What's the single biggest red flag in a solar proposal?
In 2026, it's claiming a 30% federal tax credit on a cash or loan purchase. The credit no longer exists for homeowner-owned systems. Right behind that: inflated production estimates.
Should I trust online solar reviews?
Read reviews from multiple sources (Google, BBB, SolarReviews, Yelp). Pay attention to recent reviews and how the company responds to complaints — not just the star rating.
Is a higher-priced bid always better?
No. Sometimes the higher bid is just a higher commission. Compare equipment quality, warranty length, and installer reputation — not just price.
What if I already signed and now see red flags?
Most states have a 3-day right of rescission for home sales contracts. Read your contract for cancellation terms, and act fast — typically within 72 hours of signing.