Rooftop Solar Has a Big — But Surprising — Racial Disparity

Higher-income people are more likely to have solar panels on their roofs. This fact has underlined the nature of home solar adoption and is responsible for any number of state, local, and now federal programs to give lower-income people access to solar power, either through subsidizing their own solar panels or letting them “subscribe” to solar power generated elsewhere.

While this seems like an obviously sensible solution — the upfront cost of solar can be around $15,000 to $20,000, and you typically need to own a single family home to get it — it’s not quite as simple as those with more money are more likely to get solar. When the University of Texas economist Jackson Dorsey and Derek Wolfson looked at data provide by the solar marketplace EnergySage, they found that, yes, those with higher incomes are more likely to buy solar — but also that what solar installers offered them and what they paid for it varied depending on the demographics of the surrounding area.

“Econ 101, there’s usually two possible reasons why you might have lower quantities in a market. One would be demand is lower, and the other would be supply is lower,” Dorsey told me when I asked what had motivated his research. While the data about high-income demand for energy transition products like solar panels or electric vehicles is plentiful, there had been less attention paid to supply-side reasons for the disparities.

Dorsey and Wolfson looked at hundreds of thousands of bids for solar installation placed in EnergySage’s 15 largest markets, including much of urban California, New York City, Washington, D.C. and metro areas in Florida, where prospective solar buyers are able to pick among bids from installers. Unsurprisingly, lower-income buyers were less likely to purchase home solar, received fewer bids overall, and, because they were likely seeking smaller systems, paid more per watt than wealthier buyers. (The researchers were able to match data from EnergySage with census data to extract demographic information about potential customers along with their location.)

What did stand out, however, is that Black households in particular got fewer bids and paid notably higher prices, a disparity that could not be explained entirely by differences in income. Low-income households were more likely to be in an area with a lower cost of living, and therefore didn’t necessarily face higher overall project costs because prices for everything tended to be lower.

Black households, on the other hand, received fewer bids and then face higher prices. “If you look at Black vs. white households, Black households get about 8% higher prices,” Dorsey told me. “On a $20,000 system, that would be $1,600.”

The reason, he determined, is not so much that installers don’t want to serve people they know are Black. It’s that they don’t want to serve neighborhoods they know are majority Black.

Dorsey put the difference down to “some kind of perceived higher cost of doing business.” Part of it could be explained by installers setting up shop in areas where they think they’ll find higher demand for their services — high-income ones — and so Black neighborhoods, which are more likely to be low-income, may be literally farther away and more expensive to serve. According to the data Dorsey and Wolfson collected, there are three installers within 10 miles of white households on average, compared to two installers on average for Black households.

There could also, Dorsey said, “be some implicit preference that they don’t want to go to those neighborhoods.” In the paper, Dorsey and Wolfson write that “some sellers may prefer to serve certain households or neighborhoods either because of intolerant views, crime rates, or other variables correlated with household demographic characteristics.”

While the study didn’t get into remediation, fixing the income side of things should be fairly straightforward, Dorsey told me. “Just making prices lower or financing terms more comparable [to high income households] should be fairly effective,” he said.

The sociogeographic side of things will be trickier to address. “That might suggest a supply side policy might be effective,” Dorsey said, “like giving installers incentives to locate in or serve communities that are getting fewer bids and facing higher prices.”

Policymakers and solar advocates are very aware of the income and race disparities in solar adoptions and have come up with a slew of policies to try and narrow them. California, which has long been the epicenter of rooftop solar (with the most attendant controversy over how its incentives are designed), has a program that subsidizes low-income households that want to install solar and incentives for affordable multifamily buildings to install solar.

The Environmental Protection Agency’s $7 billion Solar For All program also supports states, tribes, and non-profits with programs to reach low-income households. “The program will help unlock new markets for residential solar in areas that have never seen this kind of investment before,” an EPA spokesperson told Heatmap in an emailed statement. “Much of the program will fund solar projects to benefit multi-family and affordable housing, as well as community solar projects, bringing the benefits of clean energy to households that may not have had access to it before.”

Another favored solution for getting solar access to those who wouldn’t otherwise have it is community solar, where households “subscribe” to small-scale solar installations and then get credits on their utility bill as if they had physically installed solar in their homes.

The share of community solar capacity that serves low-to-moderate income consumers has grown from 2% in 2022 to 12% this year, according to data from Wood Mackenzie and the Coalition for Community Solar Access, and they project it will continue to grow to 25% in 2025.

The Inflation Reduction Act also includes an “adder” for community solar projects that serve lower income consumers that boosts existing subsidies by 10 to 20 percentage points. These community solar projects are “already seeing impact and projects on the ground,” Molly Knoll, vice president of policy for CCSA, told me.

EnergySage’s chief executive, Charlie Hadlow, said in a statement that the company is “working diligently to ensure every eligible shopper gets three to seven quotes on our platform,” and that “we welcome more installers to sign up on our platform and are actively seeking them out, with a deliberate focus on underserved areas.” He said consumers typically save 20% using EnergySage compared to what they might get on their own, and that the company also has a marketplace for community solar.

All that said, Dorsey is skeptical that “installing panels at individual rooftop” is even the best way to decarbonize. "If you want to cost-effectively reduce emissions, it’s not clear to me rooftop solar is the way to do it as opposed to utility-scale or community solar,” he said.