Manhattan, shadowed by skyscrapers, still lags in the residential department, with about 500 installations, according to the state agency. That makes Brooklyn, with 3,100, many of them added in the last few years, so notable. The borough’s typical stock includes rowhouses with a few units occupied by a landlord and a couple of tenants.

In northern climates, solar panels usually need to be tilted, to capture the most light; panels that sit flush on squared-off roofs usually don’t generate enough power, according to solar companies. And New York’s building codes stipulate that firefighters must have enough room to navigate in case of emergencies, which means glass can’t entirely cover roofs.

For years, there wasn’t much brownstone-worthy equipment. Sunrun, a 12-year-old national provider that sells and leases solar energy systems, for instance, doesn’t currently offer any flat-roof-compatible systems, a spokesman said, although some Brooklynites with angled eaves are customers.

Brooklyn SolarWorks, a four-year-old company based in Gowanus, which does most of its work in the borough, set out to fill that void.

Its “canopy” system offers tilted panels mounted nine feet in the air, which leaves enough space for a firefighter to swing an ax underneath, according to the company. Interest in the product and others offered by Brooklyn SolarWorks seems to have ramped up quickly.

In the brownstone-packed neighborhood of Park Slope, for example, Brooklyn SolarWorks installed solar systems at 13 addresses in 2016, the year after the company was founded. In 2017, the company did 23 installations there, and in 2018, it did 58, according to the state energy authority.

While established areas may have been the first to warm to the idea of solar power, up-and-coming neighborhoods seem to be coming around too.