Reverse Solar Payback Calculator
Work backwards: set a target payback period and see what electricity rate, export credit, or state incentive you need to hit it. Free, instant, no sign-up.
How this calculator works
- This calculator works backwards: instead of asking "how long until I break even?", set your target payback period and it tells you what has to be true to get there.
- It first checks whether your state's current rate and production already hit the target. If not, it computes the electricity rate, export credit, or state incentive you would need.
- This is the best tool for negotiating with installers — you can see exactly how much a lower $/W price or a state rebate shortens payback.
Example scenarios
8 years: Aggressive — typical for high-rate states (HI, MA, NY).
10 years: A common homeowner target; realistic in most mid-rate states.
12 years: Relaxed target for cheap-power states.
Data & algorithm
- Required annual savings = net system cost ÷ target years.
- Base savings = self-consumed kWh × rate + exported kWh × export credit + SREC income.
- Gap is converted into the required rate (full-retail states), required incentive % (state credit/rebate), or required export credit.
Official data sources
- Same as the ROI calculator: EIA 2026, NREL PVWatts v8, DSIRE 2026.
All figures dated 2026. Incentives and rates change — verify current values with your utility and the administering authority before making decisions.
Frequently asked questions
What if the required electricity rate is unrealistically high?
That means your state's rate/production combination makes your target payback unrealistic at current prices — solar is likely a poor fit unless incentives improve.
How do I use this with a solar quote?
Plug in your quote's $/W price. If it can't hit your target, ask the installer to lower the price or find state incentives that close the gap.