Oh boy. As a worker in a building that insisted on putting trees and large plants where they don't belong, like 9 stories above ground or wedged into tight covered courtyards, this is plan for disaster. The artificial light-catching equipment just might work on sunny days--I've never seen any in action, and I'm skeptical how well the above ground part can be integrated into a busy street without looking uglier than a cell phone tower--but think of all the energy you waste on artificial light for the other days. Green project, this is not; plants require a lot of light. That's why they grow in the sun, you know, and absolutely never in a subway tunnel. And some will still die, and then you are hauling trees, soil, and landscaping equipment in and out of a constricted space all the time.

This will be a ton more expensive than the High Line, and probably a horticultural nightmare.

Plus, people go to parks to get fresh air and enjoy a view, right? Not to inhale canned fumes in the dark...

Maybe they'll stick with hostas. If they can grow in my backyard, they can grow underground. :P

If they can make the park as bright as it would be outside (on any given day) then they shouldn't need extra artificial light.

Do you have data on whether their technology can accomplish that?

Nope, but I would doubt that it could produce as much sunlight as if there were no roof.

Even if the system were 100% efficient, if we assume that the rays from the sun are roughly parallel, you'd need as much solar dish area as the square footage of the park to pipe the same amount of light into it.

The closest thing I could find to a product is this [1] and at $8000 for a 4-foot dish, you're looking at a lot of money to harvest enough light to grow trees.

The whole idea reeks of gaga-green engineers/architects that don't understand how hard it is to grow plants; I don't think they're considering how you need to hit the tree from all angles with the light, otherwise parts of it will die. Also, lots of larger plants depend on the tracking motion of the sun to grow normally. Think about the last time you saw an indoor tree that looked like it was growing nicely: it almost certainly had a glass roof over it, because they really need that all that light to survive.

[1] http://pesn.com/2005/07/27/9600139_Fiber_Optics_Bring_Sun_In...

No blankets will be allowed, though. Or free speech.

Seriously, fuck the NYPD. They will ruin anything good that anyone attempts to build there.