Does a Rooftop Solar Photovoltaic Array Make Sense for My Building?

With sustainable energy mandates increasing and solar panel costs declining, Rich Justinn, strategic accounts manager with major roofing system manufacturer GAF, offers commercial property owners a list of questions to ask to determine whether a rooftop or other solar photovoltaic array might make sense.

With the sustainable energy mandates seen across the country and solar panel costs declining even amid productivity gains, no doubt lots of commercial property owners are wondering whether a rooftop or other solar photovoltaic array might make sense.

In his presentation at BOMA International’s Every Building conference in Seattle, Rich Justinn, strategic accounts manager with major roofing system manufacturer GAF, identified several key questions owners should be asking experts as they research prospects for PV installations:

1. What’s the right PV technology to use with my building? Various systems are available, including rigid peel and stick, flexible peel and stick, and racked panels.

2. What’s the right roof membrane to use with PV arrays? Again, options abound but will vary with respect to ease of tracking leaks, propensity to block drainage and other factors.

3. What are the critical design aspects? Experts can help determine whether it makes the most sense to lag bolts through to the sub-structure, tap recessed holes, use regular caulk under the block and other design approaches.

4. Is the roof solar ready or solar capable? The critical factor is identifying potential weight or age issues – such as erosion or wet insulation.

5. Will high reflectivity be an issue? Related degradation can be an issue in high sun areas, and if the roof is exposed to adjacent reflective surfaces.

6. Are warranties adequate? The rule of thumb here: Membranes need to be warranted for at least as long as arrays – which are typically warranted for 20 to 25 years.

7. How long can we expect these roof membranes to last? Using 60- and 80-millimeter thermalplastic polyolefin (TPO) membranes with the most advanced engineering, one should expect 25 to 30 years even at high temperatures and UV exposure.