As the world reduces its reliance on fossil fuels, one solution may be at the neighborhood Walmart.
U.S. big-box stores could power almost eight million homes if the majority installed solar panels on their roofs, according to a January report from Environment America, a non-partisan environmental advocacy group.
"One of the most obvious places to put rooftop solar is the big, flat, sunny roofs that cover America's big box stores," Neumann said. "There are societal benefits."
The "Solar on Superstores" report highlights several advantages of a widespread shift to rooftop solar on superstores.
The report's authors said the move would remove 52 million metric tons of CO2 from our atmosphere each year while helping superstores offset some of their energy spendings.
"Far and away, the biggest potential is with Walmart," said Johanna Neumann, the senior director of Environment America's campaign for 100% renewable energy. "If Walmart committed to putting solar on all their roofs, it could power more than 840,000 homes across America."
It is a step that many companies have already taken.
Walmart and Target, two of the largest retailers in the U.S., are also among the top five companies in installed solar capacity. Target said in a statement that it has rooftop solar on more than 540 stores, producing up to 40% of the energy needed in each store with a solar array.
"[We have] a goal to source 100% renewable energy by 2035," Walmart said in a written statement. "As of 2020, 36% of our global electricity needs were supplied by renewable sources. ... Onsite solar, including rooftop solar, is one of the many tools we use to meet our renewable energy goals."
Neumann said, in her eyes, the efforts do not go far enough to meet American climate goals.
"The biggest hurdle is historical inertia," Neumann said. "When Walmart looks at its business model, they are first and foremost trying to meet America's consumer demands at the lowest price possible. They need to make a business decision that makes sense, but that requires a little bit of planning and forethought."