(Feb. 7) Costco Wholesale Corporation’s mission has always been clear — buy large quantities of goods from the manufacturer and pass the savings on to club members.

But now the Issaqua, Wash.-based wholesale giant is focused on sustainability and environmentalism.

Intent on reducing its carbon footprint and cutting energy consumption, Costco is installing skylights and solar panels at warehouse club locations in Hawaii and California.

“Financially, it makes sense and it’s a good thing for the environment,” said Craig Peal, assistant vice president for energy and building controls. “We’ve tracked their (the solar power systems’) performance and they’re right on track — exactly what we expected.”

So far, nine of Costco’s 529 locations have converted to the eco-friendly design, and four more are scheduled for this year.

“The media and public have responded very positively,” Peal said. “It’s been good for us financially and we’re looking to expand more.”

The solar systems, built by SunEdison, Beltsville, Md., should produce more than 725,000 kilowatt-hours annually.

Cost varies by location, and Costco looks at each building and decides whether solar power is plausible at each location.

The project is the brainchild of the Costco Corporate Sustainability and Energy Group, a board formed in 2007, to minimize the company’s impact on the environment and increase sustainability.

Additional environmental efforts are also in the works.

“Pretty much everything is possible,” Peal said. “We do daylight harvesting, solar power, water conservation, sustainable packaging — basically anything we can.”

Other eco-friendly program proposals by Costco: an extensive cardboard recycling system and an electronics-refurbishing program.