|New York City Is Channeling the Sun to Build the World's First Underground Park|
By using mirrors to redirect natural sunlight from the surface, the city plans to foster significant subterranean plant growth.
In July, the New York City Economic Development Corporation (NYCEDC) approved the development of the Lowline, soon to be the world's first underground park. In a few years you'll be able to walk into an abandoned Manhattan trolley tunnel filled with exotic flora from around the world, all sustained by natural sunlight channeled into the cavern by an intricate arrangement of solar collectors, mirrors, and a transparent tube system.
Advertisement - Continue Reading Below
Conceived by James Ramsey and Dan Barasch, the Lowline collects light at street level by using a system of mirrors—similar to concentrated solar power mirrors—that pivot and rotate to follow the sun's journey across the sky. Once complete, the Lowline will be sourced by more than 100 of these collectors—large parabolic dishes that concentrate sunlight into beams 30 times the strength of the light experienced by pedestrians on the street.
Concept image of the Lowline to be constructed under Manhattan.
The beams of light are then funneled between a series of mirrors, which are protected inside clear tubes to prevent dust from entering the light "irrigation" system. What resembles extra-large zig-zagging florescent lights on the ceiling are actually super-concentrated photon beams channelled from the outside world.
The light is then sent to distributors—optical diffusers mounted to the ceiling made of anodized aluminum panels. These spread the light over the greenery of the park. The panels are structured in a geodesic pattern to illuminate a large space.
The NYCEDC decided to green-light the project after seeing the technology demonstrated at the Lowline Lab, an above-ground proof-of-concept in Manhattan that's currently open to the public. The mirror-and-tube system beams external sunlight indoors, creating an environment that fosters natural plant growth.
Light being channeled through tubes at the Lowline Lab.
Thanks to this unique system of mirrors and distributors, the engineers have managed to produce a full-spectrum light efficiency of about 70 percent (losing only small amounts of light that are absorbed instead of reflected at each mirror touchpoint), allowing for authentic plant life to flourish underground. Compare this to a hypothetical alternative of collecting energy from solar panels and using that electricity to power LED lights, which would create efficiencies closer to 7 percent.
Irrigator leading to distributors at the Lowline Lab.