Electricity output of US utility-scale solar generators in June 2015 was 31 times higher than the level in June 2005, according to the US Energy Information Administration (EIA). Solar generation from utility-scale facilities hit a monthly record high of 2,765 GWh in June 2015, which represents a year-over-year increase of 35.8 percent relative to June 2014.
The main driver to this growth is the continued expansion of solar photovoltaic (PV) capacity, which increased by 47.5 percent from June 2014 to June 2015. Over that same period, solar thermal capacity increased by 18.1 percent.
Between 2005 and 2010, the vast majority of utility-scale solar generation came from large solar thermal facilities. Solar thermal facilities accounted for about 85 percent of total annual utility-scale solar generation from 2005 to 2010.
Beginning in 2011, PV generation began to grow at a higher rate than thermal generation, even though solar thermal generation has also continued to expand. In 2014, the PV share was 86.6 percent of the total solar generation supplied to the electricity grid, with the 2015 year-to-date share through June being 87.6 percent.
Most of the growth in US utility scale solar generation is in California. Well over half (56.5 percent) of total solar generation came from plants in California in June 2015. Arizona (13.4 percent), North Carolina (6.7 percent), Nevada (6.4 percent), and New Jersey (3.3 percent) round out the top five contributors of solar to the grid.
As of the the second quarter of 2014, more than half a million US homes and businesses were generating solar energy. According to Lux Research, the Americas will be the fastest-growing region in the world for solar over the next four years. New installations are expected to nearly triple from 5.3 GW in 2013 to 15.4 GW in 2019.