By Emily Pontecorvo for Grist.
Broadcast version by Eric Tegethoff for Washington News Service reporting for the Grist-Public News Service Collaboration

Last year, a reader wrote in to Grist's advice column with a question: Why doesn't every roof have solar panels? A report released this week by the nonprofit Environment America and the research firm Frontier Group poses a followup question: At the very least, why doesn't every big box store have rooftop solar?

The amount of space available on the rooftops of Walmarts, Targets, Home Depots, Costcos, and other large stores and shopping malls in the continental U.S. is staggering. Environment America estimates that it amounts to 7.2 billion square feet, or about the size of El Paso, Texas. Even tiny little Rhode Island has 279 stores that span at least 25,000 square feet each.

From one perspective, these shrines to consumption represent the root cause of our climate catastrophe. But there's a potential silver lining: These stores can make up for at least some of that damage by opening up their vast rooftops to solar development. At best, blanketing these stores in solar panels could reduce the need to site solar farms in rural areas where they often face opposition from neighbors and can threaten endangered species.

The report finds that superstore roofs could generate enough clean energy to power almost 8 million average U.S. homes. Or to put it another way, rooftop solar panels on big box stores could provide half of the annual electricity that these stores currently demand.

The report is a followup to a similar analysis the nonprofit conducted in 2016. In the years since, the potential power that could be generated on box store roofs increased 9 percent - not because there are so many more stores, but because solar panels have become more efficient.

In addition to reducing demand for fossil fuel energy and potentially enabling conservation elsewhere, the report points out that rooftop solar has big benefits for the stores themselves. It reduces electricity costs directly, and can also reduce heating and cooling costs by providing shade during the day and insulation at night.

Some companies have already tapped into this potential. The report identifies Ikea, Walmart, and Target as leaders in rooftop solar. Ikea has installations on 90 percent of its U.S. locations. Walmart ranks as the top retailer involved with the Environmental Protection Agency's Green Power Partnership to help businesses procure renewable energy, but the report points out that the company is involved in a lot of renewable energy development that is not on its rooftops and could redouble its efforts to generate power on its own buildings.

Environment America recommends several ways state and federal policymakers can help get this show on the road. One is to extend the federal investment tax credit for rooftop solar for 10 more years and allow companies to claim it via direct payments rather than through their tax returns. The version of the Build Back Better Act that passed in the House last fall and is currently held up in the Senate would do both. Other options include bolstering state tax credits, offering property tax exemptions for the value of the solar equipment, or exempting the equipment itself from sales taxes.

The report also encourages states to enable other business models, like allowing companies to lease the solar panels from a third party or allowing communities to invest in the projects and earn some of the benefits.

David Hughes, an environmental anthropologist at Rutgers University, has a more radical idea. When Grist spoke with him last fall, he suggested that when the owners of these large flat rooftops fail to take advantage of their solar potential, they should forfeit their rights to do so to the community or municipality. Hughes bases his argument on a law from the 1800s called the Homestead Act, under which the government offered up plots of land (stolen from Indigenous peoples) to white settlers to cultivate. But if the homesteaders failed to do anything "useful" with it within five years, the rights to the land reverted back to the government. Hughes argues that the Homestead Act could be repurposed for progressive priorities today, ensuring that when a company doesn't take advantage of the resources at its fingertips, the local community can.

"If you're Amazon - the vast majority of their warehouses are wasting sunlight. They should not have control over those roofs anymore," Hughes told me at the time. "The community or the municipality or somebody should seize it and put panels on top of it. I'm not saying seize the warehouse - I'm just saying claim the authority to climb up there and put panels on top of it!"

Carrie Baker wrote this article for Grist.

Support for this reporting was provided by Solutions Journalism Network.


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The Keystone 10 Million Trees Partnership is making significant strides in Pennsylvania's environmental efforts.

A $4,000 grant from The GIANT Company and Keep Pennsylvania Beautiful will bring new trees to the City of Lancaster. The trees will be planted by volunteers.

Carla Eissing, Pennsylvania grassroots manager for the Chesapeake Bay Foundation, said the grant is helping to support their Mira Lloyd Dock partnership diversity award. She added the grant will support a tree planting in November at McCaskey High School.

"We will be planting 56 native trees and shrubs of varying species, depending on what's available," Eissing explained. "We are always working with our growers to ensure that we've got a good selection to choose from."

Eissing added the project leverages community partnerships and leadership. It focuses on urban beautification, stormwater reduction and increasing green spaces. The project builds upon the efforts of previous award winners who engaged with the local school district and community.

Brenda Sieglitz, Pennsylvania director of major giving for the Chesapeake Bay Foundation, applied for the grant through Keep Pennsylvania Beautiful to specifically be used for providing and purchasing the trees. She said since several other organizations are also funding this project, it has grown to involve more partners.

"Multiple of the other Mira Lloyd Dock awardees have joined together for this," Sieglitz noted. "We're really excited that we can use this funding from Keep Pennsylvania Beautiful and the GIANT company to work together to leverage such an ambitious project with McCaskey."

Each winner of the Dock Award will get $5,000 to plant trees and $1,000 to take care of them. The trees will be provided by the Pennsylvania Department of Conservation and Natural Resources Tree Pennsylvania program and the partnership.

A proposed rate hike by American Electric Power that would have affected customers in two dozen West Virginia counties is off the table for now.

West Virginia regulators dismissed AEP's case, citing incomplete documents and failure to disclosure financial information.

Courtney MacDonald, coalition coordinator with West Virginians for Energy Freedom, said while advocates would like to cheer the case dismissal, it will likely resurface.

She said residents should stay tuned.

"There were so many eyes on this case," said MacDonald. "There was a lot of outrage and frustration from West Virginians that already can't afford their electricity bills."

The proposal would have raised rates by nearly 18% - or around $29 a month for residential customers, and hundreds of millions of dollars in revenue for AEP.

The utility argues the rate hike is needed to cover increased costs involved in procuring and supplying energy.

MacDonald contended energy companies should be working to lower costs through efficiency programs and renewable power sources, instead of placing the burden on communities.

"Fifteen to 22% for schools, 25% for churches, and 25% to 30% for small businesses," said MacDonald, "which we all know in this post-COVID world are already struggling."

MacDonald added that residents who want to be involved in the regulatory process and share their views with the Public Service Commission can sign up for alerts online, at energyfreedomwv.org.

"You will get an alert to let you know that it is time to start writing letters again, and we provide a form that makes that easy to do," said MacDonald. "Within two minutes, you can have your own personalized message sent to the PSC."

Mountain State residents saw their average electricity costs jump by 90% between 2005 and 2020, an increase higher than almost all other states, according to the group Conservation West Virginia.

Connecticut Gov. Ned Lamont is pausing the state's involvement in a multistate offshore wind development deal.

Lamont cites the projects' potential costs, leaving Rhode Island and Massachusetts to collect proposals.

A Sierra Club report finds offshore wind can save New Englanders $630 million annually.

Lori Brown, executive director of the Connecticut League of Conservation Voters, said offshore wind is essential to the state achieving its climate goals.

"It's a real dangerous game to play, for the rest of us out here trying to get our climate action going, trying to get offshore wind off and running," said Brown. "And it's a huge market, and we're backing away from it for absolutely no good reason whatsoever except political gain."

Postponing offshore wind could prevent Connecticut from reaching its 2030 carbon emission reduction goal. At the same time, the state is building momentum with fossil fuels.

Enbridge is proposing a fracked gas pipeline extension from New Jersey to Rhode Island, much of which would run across Connecticut.

Project Maple is still in its earliest phases, but environmentalists worry about the hazards it can create.

Some environmental organizations feel the state's over-reliance on methane gas has led to increasing price spikes. The state's gas utilities got rate increases earlier this year that many Connecticut residents opposed.

Samantha Dynowski - state director of the Sierra Club Connecticut chapter - said along with offshore wind, the state should pursue all other cost-saving renewable energy options.

"Connecticut really should be moving forward with more solar - particularly on homes, and businesses, and parking lots," said Dynowski. "We also need to be doing more with energy efficiency. We know we can really reduce demand with energy efficiency."

She added the state can also invest in battery storage, which distributes saved-up energy for times when the sun isn't out or the wind has died down.

However, offshore wind is the most abundant renewable resource New England has.

The Union of Concerned Scientists finds offshore wind provides more power for the region in winter than current gas lines do.