Is solar actually worth it?
Short answer: often yes — but it depends entirely on your electricity rates, system cost, how you pay, and a few assumptions that quotes tend to make rosy. Here's how to judge it honestly.
Two numbers that actually matter
Ignore the glossy "save $50,000!" headline. Judge a quote on two things:
- Payback period — how many years until cumulative savings cover what you paid. Sooner is better.
- Lifetime net — total dollars ahead (or behind) over ~25 years, after the system cost and any loan interest.
A quote that can't show you these — clearly, with its assumptions — isn't giving you the real picture.
The assumptions that make or break it
Small changes here swing the answer a lot. Check each:
- Your electricity rate (and how fast it rises). Higher rates make solar pay off faster. But remember solar mainly offsets the generation half of your bill, not delivery fees.
- System cost after incentives. The 30% federal tax credit and any local rebates materially change the net cost.
- Cash vs. loan. Cash gives the best return; a loan spreads cost but interest lengthens payback. Model both.
- Self-consumption & net metering. How much solar you use directly vs. export — and what export is credited at — drives real savings. See net metering, explained.
- Production for your location. Sun, roof angle, and shading set how much the system actually generates.
- Panel degradation. Output drops ~0.5%/year; honest models account for it.
The fastest way to spot a too-good quote: ask what electricity rate, financing, and net-metering terms it assumed. If the savings collapse when you use realistic numbers, that's your answer.
Run your own quote through honest math
Rather than trust the installer's calculator (which is a sales tool), put your quote's numbers into a neutral one. SunTally's Estimate mode takes system cost, incentives, financing, your real rates, and net-metering terms, and shows payback year, 25-year net, and where every future dollar goes — and it will happily tell you a system is a bad deal.
Check your quote in 2 minutes
Enter your numbers (or drop in the proposal PDF) and see the real payback. Free, in your browser.
Run the Numbers →FAQ
What is a good payback period for solar?
It depends on your rates and cost, but cash-purchase payback commonly lands around 7–12 years in the US. Shorter is better; a loan lengthens it due to interest.
Does solar increase home value?
Owned (not leased) solar can add value, though estimates vary by market. Treat it as a bonus — the ROI case should stand on energy savings alone.
Is it better to buy with cash or a loan?
Cash gives the best ROI (no interest) but ties up capital. A loan can still net positive, but interest lengthens payback. Model both and compare lifetime net.