The first competition to conserve energy in Twin Cities commercial buildings has saved enough electricity to power 1,100 homes, its sponsors said Thursday.

Two companies won a "Kilowatt Cup" for their efforts -- Carlson Real Estate for multiple buildings in the west metro area and Lawson Commons in downtown St. Paul. Other building owners and tenants also won awards.

Xcel Energy, the Minneapolis-based utility, cosponsored the yearlong contest, called the Kilowatt Crackdown. Altogether, 86 buildings in the Twin Cities area participated, saving more than 13 million kilowatt hours of electricity, the company said.

At six office buildings in Minnetonka and Plymouth, Carlson Real Estate replaced each fluorescent tube with a new one that draws 4 watts less electricity, said Jami Silus, senior property manager.

Other changes included replacing parking-ramp light fixtures with energy-efficient fluorescents and installing motion-detection switches in stairwells -- projects that over a few months paid for themselves in lower electric bills, Silus said.

"The things we did didn't cost a lot of money," she added. "It was just tweaking what we had."

In a major change at one tower, Silus said, the company switched to staggered start-up of electrical heating systems, reducing the building's peak power load and thereby reducing Xcel demand charges. Overall, the projects saved about 7 percent to 10 percent on electric bills, she said.

Other building owners across the Twin Cities also installed more-efficient lighting, motors, heating or cooling equipment. Xcel said it distributed more than $1 million in rebates.

The two Building Owners and Managers Associations in the Twin Cities were cosponsors of the competition, which Xcel said will be repeated this year.

At Carlson, Silus said the company has decided to enter the competition again, though the next round of energy-saving efforts still needs to be thought out.

"We are going to have to get creative -- we have a trophy to defend now," she said.

David Shaffer • 612-673-7090