Solar power in the United States
Solar power in the United States includes utility-scale solar power plants as well as local distributed generation, mostly from rooftop photovoltaics. As of the fourth quarter of 2014, the U.S. has 18.3 gigawatts (GW) of installed photovoltaic capacity with an additional 1.7 GW of concentrated solar power. In the twelve months through October 2015, utility scale solar power generated 25.3 terawatt-hours (TWh), 0.62% of total U.S. electricity. At the same time, in 2015 (Jan-June), 39% of all new electricity generation capacity in the USA came from solar.
The United States conducted much early research in photovoltaics and concentrated solar power. The U.S. is among the top countries in the world in electricity generated by the Sun and several of the world's largest utility-scale installations are located in the desert Southwest. The oldest solar power plant in the world is the 354-megawatt (MW) SEGS thermal power plant, in California. The Ivanpah Solar Electric Generating System is a solar thermal power project in the California Mojave Desert, 40 miles (64 km) southwest of Las Vegas, with a gross capacity of 392 MW. The 280 MW Solana Generating Station is a solar power plant near Gila Bend, Arizona, about 70 miles (110 km) southwest of Phoenix, completed in 2013. When commissioned it was the largest parabolic trough plant in the world and the first U.S. solar plant with molten salt thermal energy storage.
There are plans to build many other large solar plants in the United States. Many states have set individual renewable energy goals with solar power being included in various proportions. Governor Jerry Brown has signed legislation requiring California's utilities to obtain 33 percent of their electricity from renewable energy sources by the end of 2020. A total of 4,324 MW of utility scale solar power plants are under construction and an additional 25,926 MW are under development, with 19,060 MW under construction or development in California.