The outlook for solar installations in the United States continues to be bright. More than 40 gigawatts (GW) were installed in 2024, with about 8 GWs installed on rooftops. According to Wood Mackenzie, a global provider of data and analytics for energy transition, solar will see steady growth looking ahead and close to 45 GWs every year through 2029, with about 10 GWs installed on rooftops each year.
Electricity demand is starting to accelerate across the country. According to the Department of Energy (DOE), the demand will grow 16 percent by 2029. This is primarily driven by the rise and continuing growth of data centers, which provide solar opportunities, especially distributed generation (on-site) solar, to satisfy the growing demand. According to the Deloitte Research Center for Energy & Industries, wind and solar accounted for nearly 90 percent of new electricity capacity in the first nine months of 2024. Solar had the more significant share, and that is expected to continue in the near future.
The expansion of solar energy continues to be fueled by federal incentives introduced by the Inflation Reduction Act (IRA), various state and local tax incentives, and public policy mandates. Moreover, the cost of solar has decreased significantly over the past two decades, improving the return on investment (ROI) year-over-year and making solar energy more accessible for more homeowners and businesses alike.
Why this matters for the metal construction industry
The growth of solar energy presents a significant opportunity for the metal construction industry. According to Rooftop Solar on the Rise, a report by The Frontier Group and the Environmental America Research & Policy Center, rooftop solar is just beginning to scratch the surface of the vast potential of available rooftop space in the United States, utilizing only 3.5 percent of that space currently. The report states, “America could produce the equivalent of 45 percent of the electricity we currently use from rooftop solar, yet, in 2022, rooftop solar provided only 1.5 percent of America’s electricity.”
This presents a clear opportunity for metal roofing to play a pivotal role. A metal roof is the most solar-friendly roof type available and the ideal platform for mounting solar photovoltaics (PV). The inherent structure of metal roofing, with its seams or ribs, naturally provides a built-in (and cost-free) platform for solar panel installation. These features act as continuous rails, providing for installing a direct-attach system and eliminating the need for the added cost of traditional mounting rails.
Service life
In the commercial/industrial market sector, a field/lab study published by the Metal Construction Association (MCA) indicates that the service life of standing seam coated steel is in the range of 70 years—double the service life of a solar system. Many alternative roofing systems will expire long before the 35-year service life of the PV system ends. This leads to costly disassembly of the PV array and reroofing and reassembly.
The service life of solar PV is well-documented, with studies from Berkeley and other sources providing evidence of their longevity. When paired with metal roofing, this combination offers an unparalleled service life and long-term performance. No other roofing material matches the service life of metal without requiring replacement. High-end tile may be the only exception, but it comes with a high price tag and is much heavier (239 Pa to 383 Pa versus 60 Pa (5 psf to 8 psf versus 1.25 psf). Mounting solar to tile is complex and tricky to do without breaking tiles, so the cost is much higher than mounting to metal.
Metal roofing is also the most sustainable roofing type (with a 98 percent recycling rate,1 steel is one of the most recycled construction materials available), which is important to the buyer conscious of environmental energy efficiencies.
Ease of installation
Mounting solar to a metal roof is easier and less expensive than any other roof type. Solar PV can be mounted on the roof’s standing seams or ribs with reliable mechanical attachment methods while preserving the roof’s integrity. This eliminates the need to measure, cut, locate, and install traditional rails, resulting in significant time and labor savings. This means solar installations not only have a lower cost but also lower collateral load, shipping/logistic expense, and carbon footprint.
Metal roof solar mounting can offer fewer components, lightweight materials, and better load distribution. It also provides a zero-penetration system for standing seam metal roofs while preserving the roof’s warranty with no holes or leaks.
Lifetime ROI
Once the decision is made to install solar, often in tandem, a new roof is required. More and more building owners are replacing their roofs with metal roofs because of their increased durability over other roofing materials and lower lifetime costs. This leads to increased return on investment (ROI) when solar PV is installed, especially when the PV array and metal roof are considered a single asset.
When computing ROI within solar financial modeling and analysis, inverter replacement is usually factored in at about the 15th year–but what about the roof replacement cost? If roof replacement is required before the end of the life of the PV system, the solar array must be completely dismantled and re-installed on the replacement roof. Often, even the initial cost of solar plus a metal roof is less expensive than solar plus alternative roof types. Factor in roof replacement at the half-life of the solar, and the advantages become greatly magnified. With metal, roof replacement is not required. The roof will still be going strong long after the service life of the solar array has expired.
Main takeaway
As the adoption of solar power continues to grow, metal roofs will continue to be a preferred choice for new installations and retrofits, strengthening the connection between the growth of solar energy and the evolving demands for metal roofing.
For details on installing solar on metal roofs, the Metal Construction Association (MCA) offers a three-part white paper series on solar PV and metal roofing at metalconstruction.org.
References
1
Modern Steel Construction (EAF statistics, May 2023).
Mark Gies is the director of strategy and market development at S-5!. He has 16 years of solar energy industry experience ranging from product development, operations, installation, compliance, codes, and standards to sales and business development. He is vice chair of the Solar Energy Industry Association’s (SEIA) mounting system manufacturers committee.