Costco is expanding its solar power initiative at a number of their Southern California facilities with a combined rated output of 2.4 megawatts.

PermaCity is now installing the systems, manufactured by Schott Solar, at Costco’s La Habra, Westlake Village, Simi Valley and Culver City warehouses. At approximately 600 kW (DC) per location, the PV systems will be part of one of the largest privately owned, multi-site commercial PV systems in the U.S., according to PermaCity, and it continues to grow.

The roof mounted system includes almost 2,000 modules around the 200 existing skylights at each store.

Earlier this month, it was reported that REC Solar was installing 2.5 megawatts of photovoltaics on four of Costco’s warehouse locations – two in Hawaii, including the Big Island and Kauai, and two in California, including San Luis Obispo and possibly Santa Barbara.

In February, Costco installed its second solar-powered energy system at its Lake Elsinore, California warehouse.

There’s a rundown on recent solar power activity from the retail industry here.