US big-box retail and grocery stores have enough rooftop solar potential to power more than 7.9 million homes – utilizing all that unused space for clean energy is a no-brainer.


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Rooftop solar on big-box retail stores

Solar installation on big-box stores would also cut greenhouse gas emissions equivalent to taking more than 11.3 million cars off the road, according to a new report released today by Environment America Research & Policy Center and Frontier Group called “Solar on Superstores: Big Roofs, Big Potential for Renewable Energy.”

The report also found that solar on superstores can provide more benefits to local communities, too, such as helping to build a more resilient electricity grid, significant cost savings, and better air quality. 

The report details national as well as state- and company-specific information for onsite solar potential. Overall, the report authors found that big box stores can produce 84.4 terawatt-hours of solar energy.

When it comes to individual states, California has the most potential capacity, enough to power nearly 870,000 average homes, followed by Florida, Texas, Ohio, and Illinois.

Among businesses, Walmart has more than three times as much annual rooftop solar potential as its next closest competitors, as per the chart below:

Company Total US square footage (sq. ft.) Annual rooftop solar potential (GWh) Number of US households brand solar could power (thousands)
Walmart       783,557,000        8,974.4            842.7 
Target       241,648,000        2,767.7            259.9 
The Home Depot       238,600,000        2,732.8            256.6 
Lowe’s Companies       208,000,000        2,382.3            223.7 
The Kroger Co.        179,000,000        2,050.2            192.5 
Source: Environment America Research & Policy Center

In addition to Environment America calling on companies to make strong solar commitments, the report recommends a number of public policies that would make ramping up solar on big-box stores more feasible.

The report’s authors assert that the highest priority is to extend and expand federal clean energy tax credits. Other important policy opportunities include:

  • Expanding state and local tax incentives for solar
  • Allowing producers to sell excess energy back to the grid
  • Encouraging community solar programs
  • Streamlining solar permitting

Johanna Neumann, senior director of the Campaign for 100% Renewable Energy with Environment America Research & Policy Center, said in an email statement:

Right now big-box rooftops have one function: cover the store. But that space has potential to do so much more.

To reach our clean energy goals, we need strong public policy and committed private action. Big-box stores can be big leaders on the road to a clean energy future.

Electrek’s Take

Putting solar on big-box retail roofs is one of my very favorite clean energy placement solutions. Big-box store roofs are expansive, flat, stable, wide-open spaces that generally aren’t used for anything other than covering the store.

There also isn’t going to be any pushback from NIMBYs who complain that Walmart’s solar roof ruins their view. What could be a more perfect setting?

I’d take it one step further and recommend that we cover warehouse and industrial park roofs with solar as well. It’s a tidy solution that can be implemented immediately.

What do you think of covering big-box stores with solar? Let us know in the comments below.

Read more: Why isn’t US commercial solar’s massive potential being tapped?

Photo: Walmart

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About the Author

Michelle Lewis

Michelle Lewis is a writer and editor on Electrek and an editor on DroneDJ, 9to5Mac, and 9to5Google. She lives in White River Junction, Vermont. She has previously worked for Fast Company, the Guardian, News Deeply, Time, and others. Message Michelle on Twitter or at michelle@9to5mac.com. Check out her personal blog.