By Jacob Kaye –

Con Edison has retrofitted one of Queens’ most notable skyscrapers with several updates to make the building more green.

One Court Square, the Long Island City skyscraper that used to be home to CitiGroup, is a 53-story building and is now home to the largest electric-efficiency retrofit at an office building in Con Edison’s history, the company said.

“The vast majority of the buildings that exist today in New York City will still be here 50 years from now, which is why energy efficiency is often our first and best tool for reducing carbon emissions,” said Amaury De La Cruz, the program manager for energy efficiency at Con Edison. “The One Court Square upgrade is a win-win-win for the customer, the environment and the reliability of New York City’s electric grid.”

The $5 million upgrade includes a new heating, ventilation and air conditioning system throughout the building and a new control system that allows operators to “dim” certain functions.

The changes to the building’s HVAC system are expected to save an estimated 4.4 million kilowatt-hours of electricity each year, or 20 percent of the building’s previous usage, the company said.

The changes are also expected to put less strain on the power grid in the neighborhood, an issue the energy company has had issue with in the past several years. Just last month, New Yorkers were asked to reduce their energy consumption on one of the hottest days of the year in order to stave off a potential black out.

“With extreme weather and a higher demand for electricity becoming far too common, we must leave no stone unturned in our effort to make Queens as efficient, resilient and sustainable as possible,” Queens Borough President Donovan Richards said in a statement. “We commend Con Edison and all involved for completing this crucial energy-efficiency upgrade of One Court Square and look forward to working with our partners on many more such projects in the future.”

The vast majority of the city’s greenhouse gas emissions – 70 percent – come from its buildings.

“It has been our pleasure working with Con Edison as a partner to achieve significant energy savings by upgrading our base building systems in a cost-effective manner,” said Peter Rosenthal, the principal, director of development at Savanna, the company that owns the building. “Our objectives at the outset of this important project were to improve energy efficiency, realize cost savings, and enhance the tenant experience at One Court Square, and we have achieved them all.”