Is Solar Worth It for My Florida House? Run the Real Math
The proposal on the door-knocker's tablet assumes your roof faces the right way, your usage never changes, and financing is free. None of that is true. Here is how to run your own numbers.
The short answer
For most Florida homes, solar can be worth it, but the salesman's proposal is not the way to decide. A proposal assumes ideal roof orientation, ignores your real usage curve, and hides financing cost inside the monthly payment. An honest analysis starts with roof age: if your roof needs replacing within 10 years, panels usually kill the return.
A solar proposal is a sales document, not an analysis
The core distinction
A solar proposal is built to close you, not to inform you. It assumes perfect south-facing roof pitch, a flat 3 to 4 percent annual utility escalation, and full production for 25 years, then folds the loan cost into a monthly number that looks smaller than your power bill. An analysis starts from your actual roof, your actual usage, and the true financed cost.
The person at your door is paid on the sale, often through a dealer network that adds a financing markup of 20 to 30 percent on top of the system price. That markup is invisible because it lives inside the interest rate, not the sticker.
The proposal will show your utility bill climbing forever and the solar payment staying flat, so the lines cross and you feel like a fool for not signing. What it will not show: what happens if you use less power than assumed, if your roof faces east and west instead of south, or if you have to pull every panel to re-roof in year eight.
None of this means solar is a scam. It means the document handed to you is optimized for a signature, and the honest version of your math looks different.
Key takeaways
- The proposal assumes ideal orientation and full 25-year production. Your roof is not ideal.
- Financing markup of 20 to 30 percent is usually hidden inside the loan rate, not the price.
- Roof age is the first variable, not the last. Panels on an old roof destroy the return.
- Your real usage curve, not the salesman's average, determines your actual savings.
Check your roof age before anything else
Roof age is the single number that decides whether the rest of the math matters. Solar panels last 25 to 30 years. A Florida asphalt shingle roof in the sun and salt lasts 15 to 20. If your roof is already 12 years old, you will be paying to remove and reinstall the entire array halfway through the panel's life.
That removal and reset (detach and reset, in installer language) runs roughly $1,500 to $6,000 depending on system size, and it is rarely mentioned in the proposal. Stack it on top of a re-roof and you have wiped out several years of solar savings in a single week of labor.
Insurance is the quiet second problem. In Florida's hard insurance market, a roof past its expected life can get a policy non-renewed regardless of solar. Panels can complicate the re-roof timeline and the wind-mitigation inspection that determines your premium credits. Sort the roof and the policy first, then price solar against a fresh, insurable roof.
“The fastest way to lose money on solar in Florida is to bolt a 25-year system onto a 15-year roof. We tell homeowners to answer one question before they read a single proposal: how many years are left on your roof, honestly. If the answer is under ten, the panels can wait.”
Todd Paton, Partner, One Home Agent
Run your honest solar payback
This is the rough math the proposal skips. It uses your real monthly bill, the actual system cost after the federal tax credit, and a realistic estimate of how much of your usage solar will actually offset. Adjust the offset down if your roof faces east and west or is shaded.
Interactive calculator
Honest Solar Payback Estimator
A directional estimate, not a quote. It nets the federal 30 percent tax credit and lets you dial in a realistic offset instead of the salesman's 100 percent.
If your cash payback lands past 12 years, be skeptical. A financed deal at that payback often never actually pays for itself once interest and eventual panel removal for a re-roof are counted. If it lands under 8 years on a young roof, the case is genuinely strong.
What the salesman assumes vs. your reality
| Input | Salesman's assumption | Your reality check |
|---|---|---|
| Roof orientation | Ideal south-facing pitch | East/west or shaded roofs produce 15 to 30 percent less |
| Production over time | Flat output for 25 years | Panels degrade roughly 0.5 percent per year |
| Utility rate increase | 3 to 4 percent every year, forever | Rates rise unevenly; do not model a straight line |
| Your usage | A high monthly average | Your real winter/summer curve may need a smaller system |
| Financing cost | Folded into a low monthly payment | Dealer markup of 20 to 30 percent hides in the rate |
| Roof replacement | Not mentioned | $1,500 to $6,000 to detach and reset if you re-roof |
| Insurance impact | Not mentioned | Old roof can trigger non-renewal in Florida's market |
Notice how many of these are silent omissions rather than lies. The proposal is technically accurate under its own assumptions. The problem is that its assumptions are not your house.
The one uncomfortable truth: solar's biggest financial return in Florida often comes not from the panels but from the utility bill you were overpaying on, the roof you needed anyway, and the insurance premium you could have lowered with a wind mitigation inspection. Fix those first and the solar decision gets clearer and usually cheaper.
How AI actually helps with this decision
AI is useful here because the honest analysis is tedious, document-heavy, and easy for a homeowner to get talked out of. Pull your last 12 months of electric bills, your roof's install date, your current insurance policy, and the actual solar contract, and the repetitive comparison work becomes automatic.
That is the pattern behind One Home Agent's homeowner agents: Karen reads your utility bills to establish your real usage curve, Gloria flags how a roof age or a rooftop array affects your insurance, and Sara tracks what solar does (and does not do) to your home value. The AI does the extraction and the math. You keep the decision.
What AI will not do is tell you solar is always worth it. On a 14-year-old roof with an east-west split and a modest bill, the honest answer is often no, or not yet. A tool that never says no is a sales tool, not an analysis.
Checklist
0/9Before you sign any solar contract
The bottom line
Bottom line
Solar can be a smart Florida investment on a young, well-oriented roof for a household with high usage and enough tax liability to use the credit. It is a mistake on an aging roof, and it is never as good as the proposal claims. Decide from your own numbers, in this order: roof, insurance, usage, then panels.
Want an honest read before the salesman comes back?
One Home Agent's homeowner agents can pull your bills, roof age, and insurance into one clear picture so you decide on facts, not a tablet. See how it works.
Talk to usFrequently asked questions
Solar is worth it in Florida when your roof has 20-plus years of life left, faces roughly south, your monthly bill is high, and you owe enough federal tax to claim the 30 percent credit. On an aging roof or a low-usage home, the payback often stretches past the point where it makes financial sense.
Sources & further reading