Solar power includes solar farms as well as local distributed generation, mostly on rooftops and increasingly from community solar arrays. In 2023, utility-scale solar power generated 164.5 terawatt-hours (TWh), or 3.9% of electricity in the United States. Total solar generation that year, including estimated small-scale photovoltaic generation, was 238 TWh.
Solar power in Nevada is growing due to a Renewable Portfolio Standard which requires 50% renewable energy by 2030. The state has abundant open land areas and some of the best solar potential in the country.
Solar power in Arizona has the potential to, according to then-Governor Janet Napolitano, make Arizona "the Persian Gulf of solar energy". In 2012, Arizona had 1,106 MW of photovoltaic (PV) solar power systems, and 6 MW of concentrated solar power (CSP), bringing the total to over 1,112 megawatts (MW) of solar power. As an example, the Solana Generating Station, a 280 MW parabolic trough solar plant, when commissioned in 2013, was the largest parabolic trough plant in the world and the first U.S. solar plant with molten salt thermal energy storage.
Solar power in Colorado has grown rapidly, partly because of one of the most favorable net metering laws in the country, with no limit on the number of users. The state was the first in the nation to establish a Renewable Portfolio Standard for its electric utilities.
Solar power in Massachusetts has been increasing rapidly, due to Section 1603 grants for installations that began before December 31, 2011, and the sale of SRECs for $0.30/kWh, which allows payback for the system within 5 or 6 years, and generates income for the life of the system. For systems installed after December 31, 2011, and before December 31, 2016, the 30% tax grant becomes a 30% tax credit. There has been an appeal to the Congress to extend the 1603 program, the grant program, for an additional year.
Solar power has been increasing rapidly in the U.S. state of North Carolina, from less than 1 MW (megawatts) in 2007 to 6,152 MW in 2019, when it had the second-largest installed PV capacity of all states.
Solar power in Nebraska is used for only a very small percentage of the state's electricity, although it is rapidly becoming competitive with grid electricity, due to the decrease in cost and the 30% tax credit, which can be used to install systems of any size. In 2024, the state ranked 44th among the 50 U.S. states with 203 MW of installed capacity.
Solar power in Louisiana is ranked 34th for installed solar PV capacity as of 2017 by the Solar Energy Industry Association. The state's "solar friendliness" according to Solar Power Rocks has fallen to 50th place for 2018 as the state credit program ends and full 1:1 retail net metering is being phased out. Taxpayers still benefit from federal incentive programs such as the 30 percent tax credit, which applies to business and residential solar photovoltaic and thermal energy systems of any size.
Solar power in Kentucky has been growing in recent years due to new technological improvements and a variety of regulatory actions and financial incentives, particularly a 30% federal tax credit, available through 2016, for any size project. Kentucky could generate 10% of all of the electricity used in the United States from land cleared from coal mining in the state. Covering just one-fifth with photovoltaics would supply all of the state's electricity.
Solar power in Indiana has been growing in recent years due to new technological improvements and a variety of regulatory actions and financial incentives, particularly a 30% federal tax credit for any size project.
Mississippi has substantial potential for solar power, though it remains an underutilized generation method. The rate of installations has increased in recent years, reaching 438 MW of installed capacity in early 2023, ranking 36th among the states. Rooftop photovoltaics could provide 31.2% of all electricity used in Mississippi from 11,700 MW if solar panels were installed on every available roof.
Solar power in Oklahoma can provide 44.1% of all electricity used in Oklahoma from 19,300 MW of rooftop solar panels. This scenario is extremely unlikely though because the cost of electricity in Oklahoma is among the lowest in the nation.
Solar power in Alabama on rooftops could theoretically provide 29.8% of all electricity used in Alabama, with 20,400 MW of solar panels potentially installed on rooftops.
Solar power in Illinois has been increasing, as the cost of photovoltaics has decreased. As of the end of 2020, Illinois had 465 megawatts (MW) of installed photovoltaic and concentrated solar power capacity combined employing over 5,200 jobs. Illinois adopted a net metering rule which allows customers generating up to 40 kW to use net metering, with the kilowatt hour surplus rolled over each month, and lost at the end of either April or October, as selected by the customer. In 2011, the limit was raised to 2 MW, but is not net metering, as the term is commonly known, as it uses two meters for systems larger than 40 kW.
Solar power in Minnesota expanded significantly in the early 2010s as a result of the cost decrease of photovoltaics and favorable policies. By 2016, it began to grow quickly.
Solar power in Idaho comprised 550 MW in 2019. A 2016 report by the National Renewable Energy Laboratory estimated that rooftops alone have the potential to host 4,700 MW of solar panels, and thus provide 26.4% of all electricity used in Idaho. A large increase in the state's solar generating capacity began starting year 2015 when 461 MW of solar power was contracted to be built in Idaho.
Solar power in Montana on rooftops could provide 28% of all electricity used in Montana from 3,200 MW of solar panels.
Solar power in Vermont provides almost 11% of the state's in-state electricity production as of 2018. A 2009 study indicated that distributed solar on rooftops can provide 18% of all electricity used in Vermont. A 2012 estimate suggests that a typical 5 kW system costing $25,000 before credits and utility savings will pay for itself in 10 years, and generate a profit of $34,956 over the rest of its 25-year life.
Solar power in Virginia on rooftops is estimated to be capable of providing 32.4% of electricity used in Virginia using 28,500 MW of solar panels. Installing solar panels provides a 6.8% return on investment in Virginia, and a 5 kW array would return a profit of $16,041 over its 25 year life.
Solar power in Tennessee is capable of producing much of the state's electricity; however, the industry remains in early stages in the state. With 129 MW of solar power in 2015, Tennessee ranked 20th among states for installed solar capacity.
