Grid parity (when an alternative energy source can generate power at a cost that’s comparable to the price of purchasing it from the electricity grid) has made solar electricity economically competitive in some locations. So, commercial building owners who have a desire to be “green” can now do so cost-effectively with rooftop solar, in those parts of the country.
As a result, installations of rooftop solar systems have been trending up in recent years, bringing a set of challenges. If you’re in the market for solar power for your facility, here are some things to consider.
The first is the condition of the roofing system that’s underneath the solar array. If the roof is aging, it’s probably cost-effective to replace it at the same time as the solar system. The cost of a new roofing system will be relatively small, compared to the solar components. Plus, it’s easier to install the roof now rather than later, once the solar system is in place.
Whether the underlying roof system is replaced or not, keep in mind that a solar system on top will mean that access to the surface for maintenance will be more difficult.
The solar mounting system that’s used also has implications for the roof underneath. Attached racking (fastened to the underlying deck, trusses or purlins) typically provides more “angle-toward-the-sun” flexibility and wind uplift security. Penetrating the roof membrane with fasteners, however, can increase the potential for leaks. Ballasted mounting systems don’t penetrate the roof membrane, but add dead weight to the overall load. Can the roof structure handle it?
Make sure that the roof system warranty allows for a solar installation. “Overburden” warranties, as they are known, are designed and written to provide roof system coverage for things that are installed over the membrane: solar systems, vegetative roofs, pavers, etc. Typically, roof manufacturers will require a certain type or thickness of membrane to issue an overburden warranty.
It’s important to have a roofing professional involved in any rooftop solar installation to ensure that the existing underlying roofing system retains its integrity and/or to install a new roof system that will accommodate the solar project.
So, install solar and save money! Just plan that solar project properly so you’ll be sure not to blow those savings on future roof repair needs.