Grid-Independent Solar Payback Time Calculator
Investing in grid-independent or off-grid solar isn’t a trivial decision. If you’re taking out a loan, knowing when the system will break even helps you make the right decision.
For most of our clients, the system pays for itself within 5 to 7 years. Then, it’s all gravy: you own the assets, get almost-free power, and boost your property’s value. But don’t take our words for it. Use this calculator to see the payback timeline for your specific situation (the math may surprise you!)
Justplug — Payback Calculator
Grid-Independent Solar Payback Time Calculator
Enter your current monthly electricity bill, your estimated system cost, and your HELOC rate. We'll show you the payoff timeline and 20-year cost comparison.
Monthly electricity bill
$
/mo
Your average monthly utility bill
Estimated system cost
$
Total grid-independent system cost
HELOC interest rate
% / yr
Your lender's annual rate
Annual grid connection fee
$
/yr
Post-payoff utility connection cost
Your payback timeline
| Year | Cumulative — Utility | Cumulative — Solar |
|---|
Utility column models 6% annual rate escalation, derived from SCE's documented 83% rate increase over the past 10 years (Public Advocates Office, via Orange County Power Authority, December 2025). Solar column assumes your HELOC payment redirected from your current bill, then the annual connection fee post-payoff.