The Mandalay Bay Convention Center in Las Vegas now sports the biggest solar roof in the United States, with 26,000 panels.

NRG Energy, Inc. and MGM Resorts International said Wednesday they had completed the expansion of what they called the “nation’s largest rooftop solar array.”

On the roof of the Mandalay Bay Convention Center, the expanded solar array has more than 26,000 photovoltaic panels and produces a combined 8.3 MW dc (6.5 MW ac) of electricity, a “new national record for rooftop arrays,” said NRG Energy.

At full production, the system supplies 25% of the power demand of the entire Mandalay Bay Resort & Casino campus. 

It is projected that the expanded solar installation will displace approximately 8,400 metric tons of carbon dioxide (CO2) annually, the equivalent of taking more than 1,700 automobiles off the road, the energy company said.

NRG owns and operates the installation for MGM Resorts at Mandalay Bay Resort and Casino. Through a 25-year Power Purchase Agreement (PPA), Mandalay Bay Resort will purchase all the electricity generated by both solar arrays.

The electricity produced is also equivalent to the average annual usage of 1,340 U.S. homes. Since completion of the first phase in 2014, the project has helped provide pricing stability for MGM Resorts, while reducing the amount of energy drawn from the southern Nevada grid during times of peak electricity demand, according to NRG Energy.

The expanded project uses technology from Ten K Solar. Ten K’s REFLECT system consists of 4,644 Modules, 180 inverters and a fully integrated Ten K racking system with no roof penetrations. The racking system uses 3M Cool Mirror Film to reflect only the light wavelengths usable by the photovoltaic cells.

Ten K’s parallel cell and module architecture allows for modules to capture non-uniform irradiance coming from reflected light. The architecture further eliminates any single points of failure, increasing total system availability and reducing operation and maintenance costs.

“Companies like MGM Resorts are driving an evolution in America’s energy mix as they seek cleaner sources of power that provide more certainty over energy costs,” said Craig Cornelius, Senior Vice President of NRG Energy and head of NRG’s Renewables group.