It is often assumed that white roofing membranes constitute the optimal solution for solar or photovoltaic (PV) installations because of their high reflectivity. However, there is much more to selecting the right roofing membrane for this type of application than its color.
Rooftop PV investments are typically based on a financial projection of a minimum of 20-25 years, so to maximize returns, the roofing system must be able to support the PV installation for at least that period of time.
Firestone Building Products appointed independent technical consultants 3E to assess the impact of the color of the roofing membrane on the long-term solar energy production on roofs. For the study, two real case PV rooftop projects were selected for comparison, one waterproofed with a black EPDM roofing membrane and the other one with a bright white TPO membrane. Both projects were evaluated for initial and aged exposure of the roofing membrane after three years, which is supposed to be the heaviest impacted period.