According to a report by the Solar Energy Industries Association (SEIA) and the Vote Solar Initiative, US retail giant Walmart ranks number one in a list which identifies the top corporate companies using solar energy in the US for on-site consumption.

Released at Solar Power International, North America’s largest solar event, the report, called Solar Means Business: Top Commercial Solar Users in the US, analyzes 42 companies in the US using solar energy. Together, they have deployed at least 321MW of PV capacity at 750 locations in 26 states and Puerto Rico.

The report also compiles a list of the top 20 US companies with the highest installed PV capacity. In order of ranking, Walmart comes on top, followed by ), Costco Wholesale, Kohl’s Department Stores, IKEA, Macy’s, McGraw-Hill, Johnson & Johnson, Staples, Inc., Campbell’s Soup, Walgreens, Bed, Bath & Beyond, Toys ‘R’ Us, General Motors, FedEx, White Rose Foods, Dow Jones, Snyder’s of Hanover, ProLogis, Hartz Mountain Industries and Crayola.

Among the top three, Walmart has an installed capacity of 65MW, Costco has 38.9MW and Kohl’s has 36.5MW. In terms of the number of PV systems installed, Walmart, again, ranks number one with 144 systems in place, followed by Walgreen with 134 systems and Kohl’s with 124 systems.

“Walmart has an ambitious commitment to be powered entirely by renewable energy, and we’ve made significant progress toward this goal in recent years as renewable energy options, especially solar power, have become more affordable,” said Kim Saylors-Laster, vice president for energy at Walmart. “We have plans to continue our investment in solar energy, expanding the number of locations powered by the sun, and we hope to use our scale to drive down prices for all renewable technologies.”

Combined, the top 20 companies have an installed PV capacity of at least 279MW which, the report highlights, is enough to power 46,500 households. Moreover, the top 20 companies, together, have more than 1.2 million PB panels installed in their systems which help to generate an estimated US$47.3 million worth of electricity every year.

As highlighted by the report, the take-up of solar energy has been, in part, due to the rapidly falling cost of solar energy which has made investment in solar power much more appealing for American businesses. Indeed, the report noted that between Q2 2011 and Q2 2012, the average price of a completed commercial PV system decreased by nearly 14%.

The findings in this report are also in line with another recent report which confirmed the continuing boom in PV installations across the US. The latest report showed that installations reached 742MW in the second quarter of this year, up by 45% over the prior quarter, and by 116% over the period a year ago.