FOAM & SOLAR CASE STUDY: POLYPAC, INC.
With a keen eye on lowering energy expenses, Polypack Inc. sought to install a solar power system on the roof of its coastal Florida facility. However, ownership was wary of how the system, with its thousands of screw holes, would impact the structural integrity of the facility’s 50,000 sq. ft. roof–a crucial concern in a hurricane-prone area. The only option for Polypack was installing a uniquely designed PV system with a non-penetrating mounting system.
Before the Monolithic Solar System could be installed, the design had to be tested to ensure it conformed to building codes. A third-party testing lab from Miami performed pull-tests in accordance with Miami-Dade Standards. The test procedure was fairly involved. First, a stand was affixed to the roof surface with low-rise foam and roofing foam. After the foam cured, the testing team used a specialized apparatus to gauge the strength of the foam’s hold. When all was said and done, the system withstood a pulling force of nearly 6,000 lb./sq. ft., which was cut in half to nearly 3,000 lb./sq. ft., per Miami-Dade Standards. In any case, the strength of the system well exceeds even that of mechanical fastening via screws.
With testing passed and the plan set, the facility’s roof was inspected and a couple of areas received minor repairs. The solar panel stands were then placed in their specified locations. A roofing contractor was brought in to install the SPF roofing system, while an electrician was later brought in to install the solar panels.
A major goal of the project was being able to track performance of the PV system. Polypack wanted to know how much electricity was being produced by the entire system, of course, and also how much each individual panel was contributing, as the company purchased several different types. Since the system was installed, it has become evident that the panels all perform roughly equally, regardless of whether they’re pricey panels produced in the U.S. or less expensive panels from China.
The complete system including the mounting qualified for the Federal 30% tax credit and accelerated depreciation in five years. The system produced about 80% of the facility’s electricity in 2014–a rainier-than-average year–and Polypack is expecting a payback period of less than 6 years.