Even more so than the High Line, after which it was named and somewhat inversely inspired, the Lowline is one of the most intriguing urban propositions to come along in some time.

Not only is building a mole-man-style park under Delancey Street a daring proposition, but so is the technology of solar arrays behind it that could be adapted to bring natural light deep into office buildings, hospitals, mines, even prisons.

If only it didn’t seem like such a pipe dream, bureaucratically as well as technologically. The de Blasio administration is, at least, helping get over one of those roadblocks.

On Wednesday, City Hall gave the project its first official approvals. After an eight-month bidding process, the Economic Development Corporation selected the Lowline as the designated developer for the underground trolley terminal at the base of the Williamsburg Bridge that has been disused for nearly seven decades.

No one else submitted a proposal, which made the choice that much easier. “When they first presented it to me, I thought, That is some crazy, smoking-dope stuff — let’s check it out!” Alicia Glen, the exuberant deputy mayor for housing and economic development, said in an interview Wednesday.

“We’re very excited about taking interesting technology, and the way the tech ecosystem is converging around cities, to solve civic problems and objectives.”