Solar Panels, Metal Roofs Have Natural Symbiosis
Solar panels present a natural symbiosis with metal. The seams between roofing panels are a good place to anchor photovoltaic panels, without the necessity of punching holes in a shingle or membrane roof. "You don't have to worry about some solar integrator messing up your roof and finger-pointing," Buchinger says. Further, the life expectancy of a photovoltaic system is 20 to 25 years. A conventional roof at some point would have to be torn out underneath it, but with metal, "the PV system will wear out before the roof has to be replaced," Kriner says.
What's more, Bush says, "with metal, you're solar-ready, even if the building owner isn't ready to put a solar system on." Buchinger agrees: "If you think you want a solar array in the next five to 10 years, put a metal roof on, because it'll still outlast the solar array."
A recent innovation is metal roof panels with photovoltaic laminates directly built in, which offers solar-power-generating capacity with no extra installation costs. "You just bring in your electrician after it's all installed and connect it to the grid," Buchinger says.
Another green advantage is recycling — many metal roof and wall panels are made from a large percentage of recycled content and can be recycled at the end of their useful lives. "It's not like asphalt shingle that, when its time is up, it winds up in a landfill," Croucher says. He adds that aluminum panels typically contain 60 to 85 percent recycled content, copper about 45 percent, and steel at least 25 percent. "The metal has an inherent value which provides the incentive to recycle," Thimons says.
Metal is "the ideal substrate for rainwater harvesting," Kriner says; it is designed to shed water, and the surface is inert, so no oil or other pollutants will leach out, making the water suitable for outdoor sprinkling.
Facility managers may appreciate the technical benefits of a metal building envelope, but aesthetics can add architectural drama to any building, say experts. A pitched metal roof can "dramatically change the aesthetics of a building built 20 or 30 years ago," Bush says. The retrofit can add hips or dormers and extend to walls.