Despite Atlanta’s many sun-filled days—on average, the city counts 217 sunny days per year—very few metro residents are capitalizing on those abundant rays to power their homes.

That’s according to a new report from Cape Analytics, which found that Atlanta resides in the basement of 21 metro areas that utilize solar panels, ranking just above Detroit at the bottom.

In fact, Atlanta has just 64 homes outfitted with solar panels per 100,000 residences.

That’s a far cry from the 10,195 homes per 100,000 in San Diego, the country’s leader, equipped with solar panels. Not surprisingly, the top five cities making the most of solar power are all located in California.

Even Chicago and Seattle, both of which have fewer sunny days per year than Atlanta, rank higher than Atlanta for solar panel use.

Given that many intown residents exhibit a progressive attitude that ostensibly would embrace solar power, it seems plausible that more Atlanta homeowners would readily adopt solar panels than those in competing cities.

So why isn’t Atlanta taking advantage of the sunshine?

Some theories claim Atlanta’s tree canopy and even its many hills discourage widespread solar use. However, the more likely reason boils down to economics. Installing a solar panel power system, after all, doesn’t come cheap.

While there are no state incentives available—previous tax credits have expired—homeowners can opt for the Federal Solar Tax Credit. That allows Americans to deduct 30 percent of total solar-panel system costs on federal tax returns, provided they meet specific guidelines.

However, even that credit won’t last forever.

The current credit of 30 percent is available through the end of the year, after which the percentage is reduced for 2020. The credit ends altogether in 2021.

As such, an impetus for installing solar power in the coming years is rapidly diminishing, leaving us to wonder if Atlanta will ever get on the renewable energy bandwagon.