An integrated PV system that uses foam as an anchor instead of rack penetrations was recently installed on the roof of the SunTrust Building in St. Petersburg.
Solar may be one of the fastest growing sources of renewable energy, but many facility managers have reservations about the necessary roof penetrations and weight load associated with PV racks. Integrated photovoltaics are an alternative that can alleviate these concerns. The SunTrust Building is Florida’s first commercial roof to install a new form of this technology.
Installed by Solar Energy Management (SEM), the 50 kW solar system occupies 50,000 square feet of roof space. Instead of conventional ballasted or mechanically attached racks, it uses a sprayed urethane foam distributed load attachment system that supports the solar array without penetrating the roof.
“This system allows the weight load to be distributed across the entire field of the roof, every 4 feet, without drilling holes into the structure,” explains Scott McIntyre, CEO of SEM.
Working with a structural engineer, SEM also conducted lift tests of the roof and stanchions used with the integrated solar system. “The lift tests far exceeded our expectations,” McIntyre adds. “The results showed that the solar attachment system can withstand wind loads in excess of 200 mph, which is important in Florida.”
Prior to installation, SEM worked with Wallace, Welch & Willingham Insurance, owners of the SunTrust Building, to establish a cost of energy per square foot. They discovered that a solar array could save 40% of the company’s energy costs.