Where you live affects how much you pay for solar. Take a look at this graphic from Solar Power Rocks, which advocates for better state-level policy. In Washington D.C., it will take five years to recoup what you pay for a 5MW system. In Georgia, for the same system, it will be more like 20 years.
The main reason is the level of state incentives. Some states offer feed-in tariffs, utility rebates, tax credits and exemptions, and so on. Others aren’t so generous. Some utilities are required to buy solar power, and to pay owners the what they’re charged to consume energy ("net metering"). Some aren’t.
Solar Power Rocks’s ranking takes a measure of all the policies in place, then assigns a grade (from A to F). It also ranks the states from 1 to 51 (including D.C.). On top is Massachusetts, which offers property and sales tax exemptions, mandates net metering, and has a "solar carve out" (a target for solar power). With 4.45 points out of five, it narrowly beats out Maryland (4.3), and New York (same score).
Here, for example, is what the report says about New York, which has a pay-back period of six years:
"Never content to follow the mold, the Empire state carved its own path to solar success; where Maryland and Massachusetts rest their solar-financial laurels largely on the backs of impressive performance payment programs, New York ratchets up the state rebate and tax credit programs to achieve even faster payback timeframes."
Meanwhile, Alabama, Arkansas, Georgia, Mississippi, Nebraska, North Dakota, Oklahoma, and Wyoming all get an F grade. Oklahoma comes last in the ranking. It offers nothing in the way of incentives for residential installation, and its 15% "renewable portfolio standard" (its target for renewable energy production) is a goal that’s easy to ignore (other states penalize utilities for non-compliance).
Solar Power Rocks wants all states to implement the most supportive policies. But, until that happens, you’ll have to choose where to set up your solar panel. Better Massachusetts than Mississippi.