Home solar energy use has exploded in the United States over the past decade, but most of that growth has come from just two states.
The number of homeowners and businesses that have connected solar panels to power grids has increased more than tenfold since 2012, from nearly 234,000 customers to around 3.2 million this year. Arizona and California account for half of those customers, according to an analysis of data from the US Energy Information Agency, or EIA.
When the numbers are adjusted for population, Hawaii leads the nation with nearly 20 solar customers per 100 households, followed by California and Arizona.
Most states have little solar presence. Montana, Nebraska and Wyoming represent less than 1% of solar customers in the country. Alabama, Georgia, and Mississippi collectively have approximately 1,500 customers with solar panels connected to utility grids.
EIA data only shows customers who participate in net metering, a billing method that allows customers with solar panels or wind turbines to earn credits on their bills by reselling some of the energy generated to the local power grids. This does not include those using solar panels to live off the grid or energy captured from large-scale solar farms that utilities can purchase and distribute to customers through traditional transmission lines.
Almost all states have net metering requirements, which mandate some form of payment for excess energy. The billing mechanism is not mandatory in Alabama, South Dakota and Tennessee.
Solar reimbursements are complicated. Not all states make it easy to repay energy supplied, and state legislatures and regulators have taken steps to reduce payments.
A patchwork of regulations allows customers to receive credits in most states, but some utilities have sought to limit what they reimburse customers for their excess solar power. In Mississippi, rates are so low that only 586 households have opted for the service.
Florida Governor Ron DeSantis, a Republican, last month vetoed a move to gut the state’s solar credits, saying it would hurt residents already reeling from rising fuel prices. gasoline and groceries. Florida ranks sixth in the nation, with nearly 115,000 customers benefiting from solar power.
California regulators delayed a decision last month to cut solar power payments to customers.
Small installations accounted for about a third of all solar power generated in the United States last year, according to Department of Energy data.