Journal of Property Management - January/February 2010

Geography aside, the energy savings properties experience from installing a solar power system also hinges on the level to which a building is retrofitted.

Solar electric technology and solar hot water technology are two common solar retrofits—both typically involving rooftop solar panels. Solar electric technology is intended to offset a building’s electric bill, whereas solar hot water technology offsets a building’s natural gas bill.

Mike Hall, CEO of Borrego Solar Systems Inc., in San
Diego, said it’s difficult to determine which solution
would conserve more energy because they are “attacking
different parts of a building’s energy usage.”
However, he said because properties typically require
more electricity than hot water—depending on building
activity and how much water it is heating—hot water
projects are usually smaller ticket items, and the savings
impact is also usually less.

Regardless of the type of retrofit, retrofitting a building to be solar powered is fairly simple. To retrofit Wayne National Forest headquarters, a raised panel tray was merely clamped to the roof, said Steve Marchi, forest engineer.

“We didn’t have to rewire and [now] we don’t need any batteries,” he said.

Retrofits become more complicated if structural upgrades need to be made. When structural engineers evaluated the roof of the Stone Harbor Public Works building in Stone Harbor, N.J., they found the building needed some structural steel upgrades to support their 315-panel solar system.

CarefUl ConSIDeratIon

To determine the level of solar retrofit a property will need, property owners and managers should carefully evaluate their buildings. The evaluation process begins with the roof. While most office and residential buildings are engineered strong enough for a system, roof loads remain a top concern.

“A lot of people overlook this part of it, but you have to determine if your facility is able to accommodate the installation physically,” Stolatis said.

If roof loads pose a challenge, other options exist. If the lot of land housing the property is large enough, solar panels may be mounted in the ground. Also, many property owners install solar panels on top of parking lot carports.