BOULDER - Greeting cards maker Blue Mountain Arts has completed the installation of solar panel arrays on four of its buildings in Boulder.

The four systems can produce 186,000 kilowatt hours of electricity annually, making the installation one of the largest privately owned photovoltaic solar array in Boulder County.

Denver-based SolSource Inc. installed the systems that included a 98.2 kilowatt system at a Blue Mountain Arts' warehouse in Boulder, which can produce 139,000 kilowatts per year - the largest of the four systems; a 19.6 kilowatt system in the Boulder Democratic Building; a 12.6 kilowatt system at Blue Mountain's headquarters in Gunbarrel; and an 8.4 kilowatt system at an office building in downtown Boulder. SolSource used SolarWorld USA modules, which are 100 percent made and assembled in the United States.

Laura Watkins, a spokeswoman for Blue Mountain Arts, said the four systems can provide approximately 32 percent of the company's electricity. Brian Stern, SolSource's director of commercial and government projects, said the four solar arrays can save an estimated 376,351 pounds of carbon dioxide per year from entering the atmosphere, equal to avoiding 418,169 miles in average passenger car driving per year.

Blue Mountain Arts also upgraded its building lighting system by installing energy efficient ballasts and full-spectrum compact fluorescent lamps that will save 54,000 kilowatt hours, equivalent to removing 153,070 pounds of carbon dioxide from the atmosphere.

Blue Mountain is using recycled materials in its products and is recycling an average of 117,000 pounds of shipping, packing and paper materials per year.