Many of them are more than one million square feet and are in the top 0.1%, by size, of all U.S. NFL stadiums are some of the largest sport venues in America. “They’re not just demonstrating great leadership in efficiency, they’re spreading the word to millions of people across the country.” Department of Energy report examining how sports teams and venues can save energy. 'These iconic stadiums are using the most innovative technologies and strategies today to save energy and water,” said Jason Hartke of the Building Technologies Office, who spearheaded a recent U.S. Many NFL stadiums are scoring big on energy savings and tackling waste at the same time-adding even more value to the game day experience. And, while most fans will be focused on what’s happening on-the-field, there’s another storyline already forming off of it. September kicks off the start of another football season.