Solar power in the United States

Solar power in the United States has grown from a niche technology to a major source of electricity generation, becoming one of the fastest-growing energy sectors in the country. Driven by falling costs, federal and state policies, and corporate investment, utility-scale solar farms and distributed rooftop installations now contribute significantly to the national grid. The sector's rapid expansion is central to national goals for decarbonization and energy independence, with major projects located primarily in the sun-rich Southwestern United States.

History

The modern era of solar power in the U.S. began with research at institutions like Bell Labs, which developed the first practical photovoltaic cell in 1954. Federal support increased during the 1970s energy crisis, leading to the creation of the Solar Energy Research Institute, later renamed the National Renewable Energy Laboratory (NREL). The Energy Policy Act of 2005 and subsequent American Recovery and Reinvestment Act of 2009 provided crucial investment tax credits that spurred early commercial development. Landmark projects like the Solar Energy Generating Systems in the Mojave Desert demonstrated the viability of concentrated solar power, while the 2010s saw explosive growth in photovoltaic installations led by companies such as First Solar and SunPower.

Solar power by state

Solar generation is heavily concentrated in states with high insolation and supportive policies. California leads the nation by a wide margin, home to massive installations like the Solar Star project and the Ivanpah Solar Power Facility. The Southwestern United States, including Arizona, Nevada, and Texas, also hosts significant capacity. In recent years, markets have expanded in the Southeastern United States, with major growth in Florida and North Carolina, as well as in northeastern states like New Jersey and Massachusetts which have robust renewable portfolio standards. The Midwestern United States has seen increasing development, particularly in Illinois and Ohio.

Solar thermal power

Concentrated solar power (CSP) plants use mirrors to focus sunlight, typically heating a fluid to drive steam turbines for electricity generation. The U.S. pioneered utility-scale CSP, with notable projects including the Ivanpah Solar Power Facility in California and the Crescent Dunes Solar Energy Project in Nevada. While CSP development has slowed compared to photovoltaics due to higher costs, it offers the advantage of integrated thermal energy storage, allowing for power generation after sunset. Research continues at facilities like the National Renewable Energy Laboratory and the Sandia National Laboratories to improve efficiency and reduce costs.

Photovoltaic power stations

The U.S. is home to some of the world's largest photovoltaic power stations, most located in the sunny Southwest. The Solar Star project in California was one of the largest upon completion. Other major facilities include the Topaz Solar Farm and the Desert Sunlight Solar Farm in California, and the Copper Mountain Solar Facility in Nevada. Recent giant projects have been built in Texas, such as the Permian Energy Center. These utility-scale plants are often developed by firms like NextEra Energy Resources, EDF Renewables, and Invenergy, selling power through long-term agreements to utilities including Pacific Gas and Electric Company and Southern California Edison.

Government support and policy

Federal policy has been instrumental through the Investment Tax Credit (ITC), which provides a tax credit for solar systems, and the Production Tax Credit for certain projects. The Department of Energy funds research through the SunShot Initiative and its successors. At the state level, Renewable Portfolio Standards in states like California and New York mandate utilities to source a percentage of power from renewables. Net metering policies, which vary by state and by utilities like Dominion Energy and Xcel Energy, have also driven rooftop solar adoption. Recent federal legislation, including the Inflation Reduction Act of 2022, has significantly expanded and extended tax credits.

Economics and growth

The cost of solar electricity has plummeted due to economies of scale, technological improvements, and global supply chains dominated by manufacturers in China. This has made solar competitive with fossil fuels like natural gas in many markets. Annual installations now regularly exceed 20 gigawatts, with the Solar Energy Industries Association reporting sustained growth in both utility-scale and residential segments. Major corporations like Amazon, Google, and Walmart have become significant purchasers of solar power through power purchase agreements. Future growth faces challenges including interconnection queue delays, trade disputes over imported panels, and the need for expansion of the transmission grid managed by entities like the Federal Energy Regulatory Commission. Category:Solar power in the United States