US retail centers have 62.3 GW of rooftop PV potential, study finds

The U.S.’s love of strip malls, hyperstores and out-of-town shopping centers could deliver a powerful shot in the arm for the country’s clean energy efforts, with a study by Environment America finding that the nation’s 102,000 ‘Big Box’ retails centers could host 62.3 GW of rooftop solar PV capacity.

According to the study, there is 4.5 billion square feet of available rooftop space atop the malls, warehouses and supercenters of the U.S. If every single roof was to be fitted with an appropriately sized solar system, the 62.3 GW of solar PV generating capacity could meet the electricity needs of seven million typical households.

For the stores themselves, there is a financial incentive to go solar. The report found that Big Box buildings could lower their electricity bills by an average of 42% by installing solar PV, collectively saving the retail industry $8.2 billion a year.

Of those companies that currently have the most rooftop space nationwide, the ten largest could host 17 GW of solar PV capacity. This top ten includes Walmart, Target, Home Depot, Lowe’s, Sears Holdings, Macy’s, J.C. Penney, Kohl’s, Costco and TJX.

A recent study of the retail sector by the Solar Energy Industries Association (SEIA) found that Walmart is the leading proponent of rooftop solar in the U.S., with 142 MW already installed. The same SEIA survey found that the nation’s top 25 companies have 1,462 solar systems installed on their premises across the U.S.

Rarely shaded, largely flat, and covering vast – and growing – expanses, retail center rooftops are ideal locations for solar installations. The National Renewable Energy Laboratory (NREL) found in a recent study that the rooftops of the U.S. as a whole could host enough solar energy to meet one quarter of the country’s power needs, and by solar panels close to where the power will be consumed, transmission losses can be vastly reduced.

Environment America estimates that as much as 203 million MWh of electricity is ‘lost’ during transmission on an average year – approximately 5% of all electricity generation nationwide.

The report suggests that the implementation of net metering programs, greater third-party financing options, more engaging community solar initiatives and a streamlined solar permit and interconnection process can help nurture more favorable conditions to compel more retail giants to adopt solar power.

"Officials at all levels of government should implement solar-friendly policies that help to accelerate adoption of solar energy by America’s businesses," the report concludes.