Buying
How to read a solar proposal
American Solar Savings Editors · Published 2026-10-10 · Updated 2026-11-01
A proposal is a stack of claims. Separate them.
The hardware
Modules and inverters should have model numbers. "Tier one" is not a model. Warranties should say who honors product, performance, and workmanship, and for how long. If the workmanship warranty dies with the installer, say so out loud.
The energy
Look for tilt, azimuth, shade, and the weather file. Compare the annual kilowatt-hours with a simple PVWatts run. They will not match exactly. A gap of 40 percent needs an explanation.
The money
Find the cash price even if the cover page is a monthly payment. Dealer fees and interest hide there. Find the export price used in the savings chart and the name of the tariff. If that price is the full retail rate and your utility does not pay that, the chart is wrong. Fixed charges that remain should not be counted as savings.
The omissions
Roof replacement, a main-panel upgrade, and interconnection fees are either inside the price or they are extras. Unstated extras are how a low price grows. The questions list is the same test in shorter form.
Our estimate is not a proposal. If the proposal and the estimate disagree, the more specific document wins only after its assumptions survive this read.
See a labeled estimate for your bill
Enter a ZIP code and a typical electric bill. The result is an estimate, not a quote, and it shows the assumptions.