U.S. solar energy capacity more than doubled in 2010 and government incentives could help it to double again in 2011, according to a report from the Solar Energy Industries Association (SEIA) and GTM Research.

The total capacity of photovoltaic and solar thermal power plants installed was 956 MW, compared to 441 MW in 2009 said the report, the U.S. Solar Market Insight: 2010 Year in Review. Solar reached a cumulative installed capacity of 2.6 GW in 2010 with a value of $6 billion, up from $3.6 billion in 2009.

In total, 878 MW of PV systems were installed in 2010, a 102 percent increase from the 435 MW in 2009. Utility-scale PV projects had 242 MW of capacity installed in 2010, more than double the amount in 2009. Currently, there are 700 MW of PV projects scheduled for a 2011 completion date.

Cumulative concentrated solar power projects capacity is 507 MW in 2010, and 78 MW of solar thermal power plants were installed in 2010, according to the report.

The U.S. has 41 concentrating solar power (CSP) projects in the pipeline for a total of 9 GW of capacity under development in the Southwest. The total capacity installed in 2010 was 77.5 MW.

The CSP market for 2011 is expected to be a light one with few projects expected to be completed this year. However, there are power purchase agreements signed for 6.4 GW of CSP projects with expected completion between 2011 and 2017. At least eight projects are scheduled for completion in 2013.

California was at the top of the list of PV capacity installed with 259 MW. New Jersey followed with 137 MW, followed by Nevada with 61 MW and Arizona and Colorado both with 54 MW.

The report states there is some concern about the expiration of the Treasury Cash Grant program as well as a potential recession of the Department of Energy’s loan guarantee program and the negative effect that could have on the solar market in the future. Financing is currently available for developments, but projects must begin operating with available federal incentives to keep up with expected demand, the report said.

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