Lehigh County’s warehouse rooftops could power more than 52,000 households with solar energy each year, according to a Keystone Research Center analysis.

Researchers estimate the county has about 33.11 million square feet of warehouse rooftop space suitable for solar panels, capable of generating approximately 535 gigawatt-hours of electricity annually. Statewide, the report estimates Pennsylvania has 581 million square feet of warehouse rooftop space suitable for solar, enough to generate 9,391 gigawatt-hours of electricity annually and power about 924,421 households.

Researchers say the potential is especially notable in the Lehigh Valley, where warehouse and distribution centers have proliferated along Interstate 78, Route 100 and other major transportation corridors over the past two decades.

“Warehouses are everywhere in Pennsylvania, especially in central Pennsylvania and suburban communities, and their flat, unobstructed rooftops are ideal for solar,” Stephen Herzenberg, economist and executive director emeritus of the Keystone Research Center, said in a July 10 press release.

The research arrives as Pennsylvania lawmakers debate measures designed to expand solar development on industrial buildings. One proposal would require newly constructed warehouses larger than 100,000 square feet to be built with significant solar-ready roof space and would allow local governments to offer tax incentives for solar installations.

In Lehigh Valley communities where warehouse development has sparked debate over land use, the analysis suggests existing and future warehouse rooftops could provide opportunities for solar energy generation without requiring additional farmland or open space for development, according to the press release.

“Solar on warehouses is a win-win. It puts underutilized roof space to work generating clean, affordable electricity right where people live and work. And our data shows the opportunity exists in every corner of the Commonwealth,” Claire Kovach, the center’s research director, said in the press release.

The Keystone Research Center has made the results available through an interactive online map that allows residents to examine warehouse solar potential by county and legislative district. The estimates are based on warehouse and commercial building data through the end of 2024.

As discussions about warehouses continue throughout the Lehigh Valley, the report adds a new dimension to the debate: whether the roofs of existing and future distribution centers could help meet Pennsylvania’s growing electricity needs while putting otherwise unused space to work.