It's not exactly a secret that the MTA is eager to make money in order to, well, fix the subway (among other things). On Earth Day, the agency announced its newest moneymaking move: Green real estate rooftop rentals.

The MTA plans to gradually lease out 10 million square feet across their properties' rooftop spaces, specifically to companies looking to build solar panels. "The MTA hopes to achieve a significant new revenue stream from this activity, with little to no capital investment of its own, by way of leasing the valuable real estate to companies that would use it to install solar panels and generate clean electricity to sell back to the municipal grid," the agency wrote in a press release.

The MTA wouldn't say how much revenue they estimate the initiative could garner, but MTA Chief Development Officer Janno Lieber said in a statement the agency expects a "significant amount of revenue" from the plan.

The solar roof initiative's first leasable spaces are located at seven sites that include MTA bus depots, maintenance facilities, and rail yards around Brooklyn, Queens and beyond. The sites, which range from Coney Island to the parking lot of Cortlandt Station (along the Metro-North Line), were chosen due to energy demand in those respective communities, and because they boast new pavement and/or rooftops. All told, if the rooftops across the 100-plus spaces they've singled out are used for solar energy, the MTA says the panels could collectively power up to 18,000 homes.

Back in 2008, when the agency moved to install solar panels at about two dozen of their facilities around the city, the electricity generated from the panels cost roughly double than what they'd previously bought from Consolidated Edison, according to The New York Times.

The expansion into solar power has proceeded slowly in NYC, in part due to red tape involving many, many inspections. But solar energy is gradually becoming a more common presence within the city, for agencies and residences alike, as the cost of installing solar panels goes down. According to the Solar Energy Industries Association, the price of installing solar in New York has dropped 47% since 2013.

The MTA will start to hold tours for potential renters next month, with an eye on starting negotiations in the fall.

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