Iconic Grand Central Terminal, among the most fabulous old New York structures, has gotten in on the Earth Day action.

The Metropolitan Transportation Authority has completed what’s being billed as its largest-ever energy-efficiency project for $25 million at the Beaux-Arts palace, which opened in 1913.

“The upgrades will reduce harmful greenhouse gas emissions by more than 11,200 tons a year — the equivalent of removing roughly 2,140 cars from the road” and save $2.5 million in power costs each year, state officials said in a news release.

Among the changes: an installation of cooling towers, temperature controls and compressed air and steam distribution systems, air handling upgrades, and new chillers to enhance the terminal’s original cooling system.

The project is one of several the MTA is partnering with the New York Power Authority to improve energy efficiency in its facilities.

“This undertaking is the largest energy efficiency project in the MTA’s history and will reap benefits for this terminal for decades to come—all with no upfront costs to Metro-North and capital expenses to be repaid to NYPA with the money saved by reduced energy consumption.” said MTA Chairman Thomas Prendergast.