Highland Park’s streetlights were torn out in 2011 because the predominantly black Detroit suburb couldn’t pay its electricity bill after the 2008 economic downturn. Today street lamps once again cast reassuring pools of light—and this time they are cheaper, because they harvest the energy of the sun. Highland Park offers an example of what environmental justice advocates hope to do more of to bring affordable, clean energy to communities of color.

Plummeting costs have helped solar power rapidly expand in the past decade, with U.S. residential installation growing by more than 50 percent each year between 2010 and 2016. But access to this energy has not been equitable—and not just because up-front installation costs can price out people with lower incomes. A new study indicates that even when income is taken out of the equation, communities of color have installed fewer rooftop solar facilities than predominantly white communities. The data are among the first to show such an inequality in access to clean energy, a situation advocates have been reporting anecdotally for years. The results “affirm trends in disparity in adoption that are well known to practitioners, but demonstrate their existence in a robust way,” says Ben Sigrin, an energy systems modeling engineer at the National Renewable Energy Laboratory in Golden, Colorado, who was not involved in the study.

Reasons for the disparity remain unclear, but the latest findings suggest programs aimed at boosting solar power in disadvantaged communities need to consider more than just income levels. Some activists and nonprofit organizations are already moving in this direction. For example, the civil rights group NAACP—inspired partly by local activists who formed a group called Soulardarity, which helped bring Highland Park its solar street lamps—launched a year-long 2018 Solar Equity Initiative aimed at improving solar energy access to marginalized communities, including racial and ethnic minorities. “To us [energy] is just another dimension of social justice challenges,” says Jacqueline Patterson, director of the NAACP’s Environmental and Climate Justice Program. “With clean energy, not only is it often a more affordable way of accessing energy, but it also puts us in control of our energy.”

Solar Disparities

Researchers at the University of California, Berkeley saw a golden opportunity to study imbalances in solar power deployment through their access to data from Google’s Project Sunroof—an initiative that maps solar rooftop panels seen in satellite images—and demographic data from the U.S. Census. They had an inkling of possible racial and ethnic disparities but initially thought other socioeconomic factors could help explain many of them. Yet their study results, published in January in Nature Sustainability,showed that even when controlling for income levels, neighborhoods with either black or Hispanic majority populations have installed fewer rooftop solar panels than neighborhoods with no clear racial or ethnic majority. White-majority neighborhoods, in stark contrast, have more rooftop solar installations than those without a clear majority. The researchers say these differences cannot be completely explained by either household income or home ownership levels (homeowners are more likely than renters to invest in permanent solar panels). “I was not surprised to see that race and ethnicity were important, but once we controlled for income I thought the effect would be reduced significantly,” says Daniel Kammen, director of the Renewable and Appropriate Energy Laboratory at the University of California, Berkeley and a co-author on the study. “But alas, it was not.”

The study did not uncover the root of why rooftop solar panels are typically sparser in black and Hispanic neighborhoods. But the findings mesh with reports from industry and nongovernmental organizations, which have previously shown that a lack of diversity in the environmental and solar-power fields has hindered efforts to spread solar power’s benefits. Causal factors may connect to the well-documented historical pattern of racial discrimination that has left many minority neighborhoods in the U.S. stuck with problems like insufficient public infrastructure and predatory home loans. “The disparity in rooftop solar is the same disparity as in everything else,” says Naomi Davis, founder and president of the Chicago-based nonprofit organization Blacks in Green.

The study also adds to the body of research showing that black and Hispanic Americans bear the brunt of the costs of fossil fuel use. For one thing, they are exposed to higher levels of air pollution than white Americans—regardless of income levels. There are more direct economic effects as well. “This paper does highlight an energy injustice,” says Deborah Sunter, assistant professor of mechanical engineering at Tufts University in Medford, Mass. and co-author of the rooftop solar study, “because there are certain communities that are missing out on the financial benefits that come with having rooftop solar: the tax incentives, the rebates, the profit from net metering.” (The latter refers to credits received in exchange for putting excess solar power into the electricity grid.)

Shifting Strategies

There is already a movement among community activists, researchers and politicians to promote social justice in policies designed to support clean energy and fight climate change. “There is tons of leadership in communities of color that is not seen or acknowledged, and it’s growing,” says Julian Foley, vice president of communications at Grid Alternatives, a nonprofit organization based in Oakland, Calif. that helps disadvantaged communities install solar projects. The study’s results could help fine-tune such efforts by underlining the need to shift strategies from focusing only on low-income communities—since that approach may not catch neighborhoods where ethnic minorities predominate. Kammen says policymakers could, for example, recognize how credit scores have been used to discriminate in home loans on the basis of race—and could apply “positive pressure” by offering bonuses to loan seekers who add rooftop solar panels or other energy-efficiency measures.

Officials also need to be aware of how small changes in policy can have indirect but significant impacts on programs aimed at bolstering solar power in disadvantaged communities. For example, the Bishop Paiute Tribe has used both federal energy grants and California state funding for rooftop solar projects, which can slash monthly utility bills by up to 90 percent. But starting in 2020, new California rules that define disadvantaged communities according to U.S. Census tracts could make the tribe ineligible for such state funding, despite being a low-income community. “A lot of tribes are smaller than census tracts, so the income base gets diluted by surrounding communities” under the new rules, says Brian Adkins, environmental director at the Bishop Paiute Tribe Environmental Management Office.

The researchers behind the new study also hope it can encourage leaders to support environmental justice for historically disadvantaged communities—and to recognize more diverse voices on such matters. “The environmental movement in the United States has an overwhelming amount of white leadership, and even if many of those groups are doing great things, that doesn't speak towards a very inclusive effort,” Kammen says.

The advocacy work done by Davis, the Chicago nonprofit leader, has helped shape state legislation aimed at increasing renewable energy in Illinois. She has also secured funding for solar job training and has set up a social enterprise program in hopes of establishing a solar panel assembly plant in Chicago’s predominantly black Woodlawn neighborhood by 2021. Davis sees solar power as just one small piece of a bigger holistic approach to building sustainable neighborhoods, but she wants to make sure black communities are not left out of the economic transition to clean energy in the U.S. “Step back and create partnerships where money flows directly to frontline environmental justice community-based organizations,” Davis says. “And then depend on those organizations to write the story.”