Solar industry is booming in the United States, with commercial solar customers installing 103 megawatts in the third quarter, a 38 percent boom from the same period in 2009, newly released figures showed.

Along with the booming, prices have been falling, the Solar Energy Industries Association (SEIA) said in a report published by the Los Angeles Times on Thursday.

Overall, more than 27,000 homes and businesses set up solar systems in the third quarter, according to the trade group.

The average cost fell to below six dollars a watt for the first time, said the report.

By the end of the year, the U.S. industry might surpass one gigawatt of installations, between photovoltaic, concentrating solar power, and solar heating and cooling projects, according to the report.

So far, California is leading the pack, followed by New Jersey, Florida, Arizona and Colorado.

Already in the U.S., the average cost of photovoltaics has fallen 30 percent from 10.8 dollars a watt in 1998 to 7.5 dollars a watt in 2009, according to a new report from the Department of Energy's Lawrence Berkeley National Laboratory.

Costs are still falling steeply this year -- about one dollar a watt, based on data from 78,000 residential and commercial systems across 16 states.

Researches said the slide was likely caused by a combination of government incentives and declines in the cost of labor, marketing and overhead.

Globally, demand for just photovoltaics grew 196 percent to 10. 6 gigawatts in the first nine months of 2010, according to the SolarBuzz research and consulting firm. In the third quarter, the industry pulled in 17.9 billion dollars, a 74 percent increase.