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
“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.
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
“That way you are almost multitasking with the solar
panels; they are generating power and giving you shade,”
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