The use of solar energy in the United States is developing rapidly. The operating income of the US solar industry has increased from US$7 million in 2005 to US$12 million in 2006, and US$30 million in 2007 to US$70 million in 2008.
According to the forecast of Navigant Consulting Company in December 2008, the United States will increase the utilization of solar energy by 19GW from 2009 to 2016, which is equivalent to an investment of 232 billion US dollars and is expected to increase 440,000 jobs.
In the solar photovoltaic market in the United States, there is at least 2.5X10*m2 land suitable for the construction of solar power generation facilities in the southwest alone, which can accept solar radiation exceeding 4.5X1018BTU a year. Only 2.5% of solar radiation can be converted into electric energy, which can meet the entire energy consumption of the United States in 2006. The United States has put forward an ambitious plan to enable solar power to provide 69% of American electricity and 35% of its total energy (including transportation) by 2050. It is estimated that the cost of solar sales to users will be equivalent to the current conventional electricity cost, about 5 cents/(kW·h).
In 2007, both residential and non-residential photovoltaic installations in the United States experienced substantial growth. The average scale of residential photovoltaic facilities increased by 7% to 4.8kW. The average scale of non-residential photovoltaic facilities increased by 27% to 67kW. The 30 photovoltaic systems above 500kW accounted for 29% of the installed capacity in 2007. In 2005, these large-scale systems only accounted for 12% of the photovoltaic installation capacity. The development trend is that large-scale facilities will continue to occupy a larger market share.
In 2007, California continued to dominate the US solar photovoltaic market, accounting for 58% of the market share, and the annual growth rate of states outside of California was also as high as 83%. Compared with 2006, the annual solar photovoltaic installations in Nevada, Colorado, Hawaii, Connecticut and Oregon have all doubled. The statistics of grid-connected photovoltaic facilities in the first 10 states in 2007 are shown in Table 1.
| Sort | State | Capacity/MWdc |
| 1 | California | 87.1 |
| 2 | New Jersey | 16.4 |
| 3 | Nevada | 14.6 |
| 4 | Colorado | 12.5 |
| 5 | New York state | 4.4 |
| 6 | Arizona | 2.8 |
| 7 | Hawaii | 2.4 |
| 8 | Connecticut | 1.8 |
| 9 | Massachusetts | 1.4 |
| 10 | Oregon | 1.1 |
| Other total | 5.6 |
According to a report issued by the Solar Power Association of the United States (SEPA) on January 9, 2009, the number of new solar photovoltaic (PV) and concentrated solar power projects in the United States in 2008 exceeded 5000MW. In addition, the tax incentives for investment projects have been reduced for 8 years. The implementation of the extended period is expected to greatly promote the implementation of solar power projects. The American Solar Energy Industry Association (SEIA) released the 2008 American Solar Energy Industry Review Report. 2008 was the third consecutive year of growth for the American solar energy industry. The report pointed out that the United States installed 1265MW of various solar power generation in 2008, accounting for 17% of the 8,775MW capacity.
In 2008, the United States installed solar energy utilization facilities, including 342MW solar photovoltaic facilities, 139MWTh (heat) solar hot water facilities, 762MWTh pool heating facilities, and approximately 21MW solar heating and air conditioning. Despite the severe economic crisis in the United States in 2008, the demand for solar energy has grown tremendously. Solar energy is increasingly proven to be the engine of economic growth in the United States. It has created jobs for thousands of people and built some new factories in New Hampshire, Michigan, and Oregon.
In 2008, California led the way in grid-connected PV facilities with 178.6MW, followed by New Jersey (22.5MW): then Colorado (21.6MW), Nevada (13.9MW) and Hawaii (11.3MW). For solar water heating systems, the state of Hawaii takes the lead. In 2008, it installed 37% of the total solar water heating system in the United States: followed by Florida, accounting for 20%; then California accounting for 7%, Colorado and Arizona both accounting for 5 %. Some states located in the adjacent mid-Atlantic are areas where solar energy utilization has increased, with solar water heating systems accounting for 7%.
On December 16, 2009, AltaTerra Research released a research report on the US photovoltaic market. The report showed that the total capacity of grid-connected PV facilities in the United States increased at a moderate rate in the first five years. Five years ago, off-grid PV facilities accounted for more than half of the PV market. By 2008, it only accounted for about 15% of the PV market. The capacity of photovoltaic facilities in the United States in recent years is shown in Figure 1, and the capacity of grid-connected photovoltaic facilities in the United States in recent years is shown in Figure 2.
Table 2 shows the status of grid-connected photovoltaic facilities in each state in the United States as of June 2009.
The cost of PV systems installed in the United States is gradually declining, and recent developments have proved that the economics of PV will change significantly in the next few years. The 2009 investment tax incentives and exemptions will also reduce the PV installation costs for commercial users and certain residential buyers, as shown in Figure 3.
| Sort | State | Capacity/MW | market share/% |
| 1 | California | 530.1 | 67.0 |
| 2 | New Jersey | 70.2 | 8.9 |
| 3 | Colorado | 35.7 | 4.5 |
| 4 | Nevada | 34.2 | 4.3 |
| 5 | Arizona | 25.3 | 3.2 |
| 6 | New York state | 21.9 | 2.8 |
| 7 | Hawaii | 15.8 | 2.0 |
| 8 | Connecticut | 8.8 | 1.1 |
| 9 | Massachusetts | 8.0 | 1.0 |
| 10 | Oregon | 7.5 | 0.9 |
| 11 | North Carolina | 4.7 | 0.6 |
| other | 28.4 | 3.6 | |
| total | 791.0 | 100.0 |
It is expected that the development of grid-connected photovoltaic facilities in the United States will accelerate in 2010. Module prices are decreasing, and the market is facing development opportunities. The utility scale PV market is expected to reach 300MW in 2010. Overall, the grid-connected photovoltaic market in the United States will reach 1GW (1000MW) in 2010.