While the city’s highest-profile efforts have focused on the availability of housing, it is now devoting some attention to helping poorer households save money on their energy bills. Utility bills for low earners can eat up as much as 10 percent of household income, according to a report from Groundswell, a nonprofit focused on energy issues. For the highest 20 percent of earners, utilities make up less than 2 percent of expenditures. But it’s not just a matter of percentages: Poorer families actually tend to have higher utilities bills, usually because their homes are less energy-efficient. On average, a monthly utility bill cost an American household around $115 in 2013, by Groundswell’s calculations, but poorer families were significantly more likely to have bills that topped $200 every month.

So, in a city where the gulf between the rich and poor is vast, those who could most use the energy savings have had little access to it. “In the wealthy wards you had hundreds and hundreds of solar installations,” said Ted Trabue, the managing director of the D.C. Sustainable Energy Utility (DCSEU), the independent organization enlisted by the District to handle some of its efforts to improve efficiency. “We looked at Wards 7 and 8 and you had less than a dozen systems at the time. We thought, ‘Here’s the most fertile area for our installations.’”

In July, D.C.’s city council approved a bill specifying that the city’s renewable portfolio standard would require 5 percent of the city’s energy to come from solar by 2032. The District’s plan to bring solar into lower-income neighborhoods is aggressive but not unachievable, Trabue said. Part of the concern, at the outset of the project, was that residents in low-income neighborhoods simply wouldn’t know about solar panels, let alone accept the offer to install them. “When you go to someone’s house and say you’re offering something for free, there’s natural skepticism,” Trabue said. “We thought if we got 20 people to accept these solar systems in the first year we’d declare success.” They wound up installing close to 90.

Despite budgetary restrictions—and Trabue says he isn’t interested in spending any of DCSEU’s allotment on marketing—word has spread about the program, through homeowners and contractors. “I was told that I would save between 30 and 40 percent, which is major,” said Edwin Amaker, a D.C. homeowner who has participated in the program, in DCSEU’s annual report. “The less money out of my pocket, the more money I have for the family.” The single-family solar-panel program is probably the most well-known of DCSEU’s initiatives in low-income communities.

But focusing on how to ensure that renters in multi-family units can access solar savings can have an even more significant impact, Trabue says. That’s because many of D.C.’s low-income residents don’t live in single-family homes, and most are renters. But wrangling the necessary space, permits, and access required to install solar panels on apartment buildings can be tricky.

To ensure that renters can also access the savings solar brings, the District is seeking out partnerships with the owners of apartment buildings, such as the current agreement with the National Housing Trust (NHT). NHT, a nonprofit, owns and operates about eight multi-family properties in the district, with hopes of adding about three or four more over the next year, according to Jared Lang, the organization’s sustainable-development manager. The properties all contain affordable-housing units, which made the organization anxious to find new ways to keep their costs low.