PRINCETON, NJ—Construction has begun on NRG Energy Inc.'s new “ultra-green” grid resistant corporate headquarters building here.

The three-floor, 130,000-square-foot headquarters is part of the company's long-term sustainability goals that include further reducing its CO2 emissions by 50% by 2030 and by 90% by 2050.

NRG officials staged a groundbreaking ceremony for the new headquarters building on Thursday where company officials announced its new company-wide sustainability goals. The new headquarters property is being developed by Boston Properties, which signed NRG Energy to a 15-year lease for the new building.

“Having already reduced our CO2 emissions by 40% since 2005, we see a clear path to further dramatic long-term reduction as we vigorously pursue our multi-faceted, long term sustainable growth strategy,” says David Crane, NRG's CEO. “As the U.S. transitions to a renewables-driven, increasingly distributed, grid resilient energy system, we expect to be a leader both in clean energy and in converting the CO2 emissions of our conventional generation from a liability to a profitable by-product.”

The new building when completed in 2016 will feature: two on-site solar fields, with roughly 765 kW of capacity; high-efficiency LED lighting combined with daylight harvesting to reduce indoor lighting needs and energy use by roughly one-third; 12,000 gallons of rainwater harvesting capacity to reduce city water use by 80%; more than 30 electric vehicle charging stations with the infrastructure for EV-to-grid (eV2g) “back-feed” capability; off-grid capabilities and significant additional energy efficiency provided through dual-fuel generators and combined heat and power (CHP) systems for heating and cooling; and grid power, to the extent it is used, that will be 100% renewable energy through one of NRG's green retail subsidiaries.

These features will dramatically reduce electricity, water and fuel use relative to a similar-sized corporate office, company officials say.