The city of Edina saved slightly more than expected in the first year of an aggressive effort to save energy by making city facilities more efficient.

The city exceeded its goal of saving $50,000 by about $2,000, which pleased City Manager Scott Neal. Combined, the changes reduced total energy use in the affected buildings by 7.4 percent.

"It was successful," Neal said. "The idea that it breaks even from a money standpoint is all we need. The collateral benefits are just as valuable ... saving energy, putting less carbon in the atmosphere."

The city signed a $700,000 contract with consultant Mc­Kinstry in 2011. Working on 10 city buildings, the company installed more-efficient lighting and water-conserving plumbing fixtures. Solar panels were added to the roof of City Hall. And smaller changes were made: caulking cracks and crevices, replacing weather­stripping around doors, sealing door sweeps and vents to the outside.

McKinstry guaranteed savings of at least $50,000 a year, which is enough to pay the debt service on the city's contract with the firm. If savings hadn't hit that target, McKinstry was on the hook for the difference.

The savings target for the first year was reached even though software that was supposed to measure energy input from the solar panels didn't work for two months last summer. Neal said it was repaired and someone in the city now has responsibility for monitoring the equipment. The 24-kilowatt solar system offsets electricity used at City Hall.

Solar power contributed almost 2 percent of energy savings. New interior lighting generated 65 percent of savings, changes to building envelopes about 28 percent of savings and water conservation 6 percent of savings.

One of the buildings with the biggest change in electric consumption for lighting was Braemar Arena, where new lighting above ice sheets helped cut electricity use by 45 percent. Electric savings there made up two-thirds of the city savings due to lighting upgrades.

Besides City Hall and the ice arena, conservation measures were taken at the Art Center, both fire stations, golf clubhouse and maintenance buildings, two of the municipal liquor stores and the Public Works building.

The contract did not include changes at Edinborough Park, where much of the lighting is being replaced this month. Neal said the city expects to have significant energy savings there, too.