Updated 2026-10-04
The outcome depends on the retail electricity rate far more than on any other factor. Across the states verified here the range runs from 4.5 years to 26.2 — the difference between a clearly sound investment and a clearly unsound one, determined almost entirely by location.
Until the end of 2025 a 30% federal credit reduced the price by several thousand dollars and made solar appear reasonable in almost every state. It has expired. Without it, states with expensive electricity continue to perform well; most states with inexpensive electricity do not.
Hawaii (4.5 yrs), New York (6.2 yrs), Illinois (6.5 yrs), Massachusetts (6.8 yrs) — all calculated with no federal credit. The pattern is consistent: high retail rates, combined with an export tariff that pays a reasonable amount for power not consumed on site.
Alabama is the clearest case, at 26.2 years. Inexpensive grid power means each kilowatt-hour generated displaces something of little value, and a weak export credit leaves the surplus close to worthless. No degree of irradiance corrects that arithmetic.
The actual rate, not the state average. Under a tiered or time-of-use tariff with a marginal rate well above the average, the payback is shorter than any state-level figure can show. The figure to use is the one on the bill.
Daytime consumption. Power consumed as it is generated is worth the full retail rate; exported power is worth whatever the utility pays, which in some states is a quarter of that. A household occupied during the day performs substantially better.
Method of payment. Every figure on this site assumes a cash purchase. Solar loans frequently carry a dealer fee adding up to 25% to the amount financed, which is deducted directly from the return.
Expected period of ownership. A twelve-year payback is of little relevance to a household moving within four. Owned systems tend to raise resale value, but the premium varies too widely by market to be relied upon.
The state figure is the starting point; adjusting it with an actual bill and a written quotation gives the applicable result. Payback periods by state, or the incentives each state still offers following the expiry of the federal credit.
In high-rate states, yes. The fastest payback currently published is Hawaii at 4.5 years with no federal credit. In low-rate states with poor export compensation the case is much weaker: Alabama returns 26.2 years.
Three to five years for a typical system. The credit was worth roughly 30% of the installed cost, and its removal extends break-even by approximately that proportion of the original payback.
There is no single threshold, but beyond about eighteen years the payback extends past the point at which the inverter and possibly the roof require replacement, and capital placed elsewhere generally returns more.
For some households. The installer retains ownership and claims the commercial credit that remains available, so the monthly payment can fall below the utility bill it replaces. The trade-off is the loss of ownership, of any resale premium, and of a clean transfer with the property.
Privacy. Estimates for comparison between states, not financial advice and not a quotation. At least three written quotations are advisable before committing.