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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New federal funding aims to revolutionize solar energy access within New Mexico's Native American communities and benefit the state overall.

The Environmental Protection Agency's $7 billion "Solar for All" program is designed to create new or expanded low-income solar programs.

Talia Martin, co-executive director of the National Tribal Program for GRID Alternatives, said the funding will help bridge the clean energy gap in Native American communities.

"In New Mexico, tangible impacts would be for household savings," Martin explained. "Which means working directly with the tribes to ensure that the savings are going to individual households as well as to the community as a whole."

According to Martin, the $62 million EPA grant awarded to the GRID Tribal Program is its largest ever. Nationwide, the agency's program is set to help at least 4,700 households in Native American communities. Across the U.S., the EPA said the program will enable more than 900,000 low-income households and disadvantaged communities to benefit from distributed solar energy.

Martin emphasized the program will allow GRID to help bolster solar storage capabilities and implement essential upgrades, while at the same time advancing their mission to support the self-determined efforts of Native American tribes to deploy clean energy on tribal lands, arguing it will be important to recruit contractors who understand the needs of tribal communities they're working with.

"It's an amazing window for Indian Country to be involved in energy development," Martin pointed out. "We want to just help foster all these relationships that it is going to take to do that."

The state of New Mexico also received a grant of $156 million from the program to overcome existing barriers to widespread adoption of distributed solar generation. In addition to the federal money for solar, Array Technologies announced last week it will build a new $50 million solar manufacturing campus near Albuquerque.

A round of public testimony wrapped up this week as part of renewed efforts by a company seeking permit approval in North Dakota for an underground pipeline carrying carbon emissions. Economic benefits were again touted but the plan still has opponents.

Last year, North Dakota's Public Service Commission denied a permit request from Summit Carbon Solutions, which wants to build a maze of pipelines in several Midwestern states. Emissions from ethanol plants would be captured for underground storage in North Dakota.

Skott Skokos, executive director of the Dakota Resource Council, said they remain unconvinced it would be a worthwhile project.

"It felt like déjà vu," Skokos observed. "I don't think Summit did anything to relax the concerns of the public."

Company officials have submitted a new application with a revised route as they try to ease concerns about safety and landowner rights. During comment periods, Summit leaders and other speakers discussed how the project would provide economic boosts, including corn prices. However, skeptics restated their concerns about potential ruptures and lasting negative effects on the landscape.

Skokos pointed out large carbon-capture projects like these have yet to prove themselves, noting smaller initiatives are not as likely to rile up opponents. He pointed to the Red Trail ethanol plant in North Dakota.

"They're storing it, basically, almost on-site, next to the facility and they're not affecting a bunch of landowners in the process," Skokos emphasized.

The Summit regulatory case has two upcoming public hearings in North Dakota, one scheduled for May 24 and the other on June 4. The company has run into similar opposition and permitting headwinds in other states, including South Dakota.

Leaders concerned about pollution and climate change are raising awareness about a ballot measure this fall on whether the state should mandate buffer zones around new oil and gas wells.

Voters will be asked to uphold or revoke Senate Bill 1173, which would require a 3,200-foot setback around any new well near schools, neighborhoods and hospitals.

Meghan Sahli-Wells, former mayor of Culver City and a leader with the group Elected Officials to Protect America, fought to phase out the Inglewood oil field and said no community should be a sacrifice zone.

"A study from Harvard found that in California, 34,000 people died in 2018, prematurely, from fossil fuel air pollution," Sahli-Wells pointed out. "These figures are three times higher than other studies."

The Stop the Energy Shutdown campaign, supported by the California Independent Petroleum Association, opposes the setback rule, arguing it could constrict local supply and cost jobs in the industry. A court put the bill on hold pending the outcome of the November election. A "yes" vote would keep the setbacks. A "no" vote would rescind them.

Clean energy advocates are also speaking out against companies operating older low-producing wells rather than pay to shut them down and seal them up properly.

Ahmad Zahra, a city council member in Fullerton, said Assembly Bill 2716 would incentivize their closure by charging companies $10,000 a day to operate so-called "stripper wells."

"We have over 40,000 oil wells currently sitting orphaned or idle, leaking methane and volatile organic compounds into the air, water and soil," Zahra emphasized.

Other states are following California's lead. Rep. Debbie Sariñana, D-Albuquerque, New Mexico, is sponsoring a bill to require setbacks near sensitive locations since more than 32,000 children in the state attend school within a mile of an oil and gas extraction site.

"Over 80 schools in northwestern New Mexico - the San Juan Basin and southeastern New Mexico, the Permian Basin - are within one mile of an oil and gas well," Sariñana noted. "Some schools are surrounded by dozens and even hundreds of wells within a single mile."