How much you pay to power your home with solar panels varies widely across the U.S. Some states provide incentives, like exemptions on property taxes; others don't. Some allow homeowners to sell back power to the grid ("net metering"); others don't. States have lower and higher grid electricity prices, affecting how much you might save.
When all is said is done, the best states for solar are Massachusetts, New Jersey, and New York, according to an up-to-date analysis from Solar Power Rocks (SPR), a website that guides homeowners on how to get solar. At the other end of the scale are Arkansas, Oklahoma, and Wyoming, where solar is a less good investment—though possibly still a good one overall. SPR says payback periods range from four years to 18 years, and that annualized returns range from 35.1% to 3.9%. That's based on a 5KW system, average retail prices for panels in that state, current rebates and incentives, and annual grid price increases of 3.5%.
The main chart shows all 50 states plus the District of Columbia, with overall rankings in the outer ring and the 12 factors color-coded from green to red. New York, for instance, offers property and sales tax exemptions, allows metering, and requires utilities to buy a certain amount of renewable energy. So it gets an an A+ grade overall. Arkansas offers hardly any incentives (aside from some net metering), so it gets an F grade overall.
Exactly how the numbers stack up changes constantly, so it's worth digging into the latest figures. West Virginia and Kansas, for instance, repealed their renewable portfolio standard laws last year. And, under pressure from utilities, several states are considering killing their net metering law, or adding extra fees to cover grid connection costs. Also, SPR says the price of solar panels fell 13% last year on average. Across the states, it says, rooftop solar costs about the same as it did four years ago, when bigger incentives and rebates were available.
See the full rankings, including state-by-state analysis, here.
UPDATE: In December, Nevada's Public Utilities Commission
tripled fixed charges for solar customers, substantially changing the economics of solar in that state.