For as long as Elon Musk has been involved in the tech world, he has demonstrated an almost unrivaled obsession with dreaming big and boldly pursuing initiatives that objectively seem downright crazy at first glance. From his work at SpaceX to his more recent effort to create underground tunnels capable of transporting cars at speeds as high as 125 MPH, Musk, to his great credit, is a man of action.

Still, when you have as many outrageous and ambitious ideas as Musk, not everything can become a reality. That said, the idea that the Model 3 — or any subsequent Tesla vehicle — might one day feature a roof with embedded solar panels has finally been put to rest by Musk. Recall, Musk initially floated the idea of a Model 3 outfitted with solar roof technology late last year, even going so far as to say that Tesla would “probably offer that as an option.”

We will probably offer that as an option — Elon Musk (@elonmusk) November 4, 2016

A few months later, Musk revealed that he decided to scrap the idea. During a speech at the National Governors Association a few days ago, Musk said that he actively had Tesla engineers look into the feasibility of a roof embedded with solar panels before realizing that it just wouldn’t work out.

“I really thought about this,” Musk said. “I pushed my team. Is there some way we can do it on the car? Technically, if you have some sort of transformer-like thing that will pop out of the trunk like a hardtop convertible that ratchets solar panels over the car, and provided you are in the sun, that would be enough to generate 20 to 30 miles a day of electricity. It’s a difficult way to do it.”

Still, the idea of a solar panel roof atop of a Tesla vehicle sounds a lot cooler than it would actually be in practice. Given the surface area of the roof, Musk’s 20-30 mile figure seems wildly optimistic. A solar panel roof could certainly come in handy in dire situations, but it’s far from being a game-changer.

Video of Musk’s full remarks can be seen over here.