With the National Football League’s pre-season in full swing, and regular season play right around the corner, football fans from all over the country are gearing up to see their favorite teams square off. Every season, millions of fans pile into NFL Stadiums to watch the action unfold live. These stadiums are notorious for their size and technological advancements.

They also consume millions of kilowatt hours in energy.

At the height of the NFL’s energy use, the league stepped in to start implementing new “green” initiative that would help lower the league?s overall electricity consumption and the carbon footprint of these massive professional stadiums. Many of the league’s biggest stadiums have taken the challenge seriously, and started implementing new strategies to reduce their overall energy use.

While some stadiums have gone under major renovations, several teams have planned to create entirely new energy-efficient facilities and some stadiums still haven’t changed their costly energy consumption patterns, the league as a whole has made some improvements in terms of energy consumption. ElectricChoice.com has taken the time to look at all of these improvements to see what strides these stadiums have made in becoming more energy efficient facilities and ranked the top 24 most energy efficient stadiums in the league today.

1. Lincoln Financial Field: Philadelphia Eagles

Lincoln Financial Field, the home of the Philadelphia Eagles started its Go Green program with the Natural Resources Defense Council in 2003 and it quickly became the first professional stadium in the United States capable of generating its own electricity onsite.

The stadium has the largest solar-power capacity not only in the NFL but in the city of Philadelphia, with a system that includes more than 11,000 solar panels and 14 micro wind-turbines. Together these systems are able to generate more than 3 MW of energy generating ability. The combined annual production of these systems is more than four times the amount of energy that is consumed during all of the home games in a season.

Lincoln Financial Field has also been able to reduce its electricity consumption by more than 33 percent. This paired with the venue?s recycled paper program which saves about 170 trees per year, leaves this stadium topping our list of most energy efficient stadiums.

2. CenturyLink Field: Seattle Seahawks

The Seattle Seahawks have long been failed as leaders in the effort to “green” professional sports. Together with the Seattle Sounders Football Club, the team founded the Green Sports Alliance. The team’s home stadium features point-of-use lighting in all restrooms, storage facilities and concession stands. The stadium is one of the only in professional sports to receive the EnergyStar Portfolio Manager Partner Certification.

Since first implementing their greening efforts, the facility has reduced its annual utility costs by 21%. This is in large part thanks to the stadium?s new 1,350 solar panels installed on the ring outside the stadium. These solar panels are able to produce 830,000 kWh per year. The facility also replaced its striking light display with LED light bulbs.

3. Levi?s Stadium: San Francisco 49ers

In 2014, then then newly constructed Levi?s Stadium became the first stadium of its kind in the U.S. to receive LEED Gold Certification as a new construction building. The goal of the stadium during construction was to create a solar energy system that could collect enough energy year round to completely power the teams 10 home games every season.

This goal of reaching zero net power was made possible through the NRG Energy 375 kW solar power system. The stadium also installed a 27,000 square foot green roof to provide insulation and reduce heating and cooling costs. The stadium also currently uses LED lighting to illuminate approximately 40% of the stadium.

4. MetLIfe Stadium: New York Giants and New York Jets

When MetLIfe Stadium opened in 2010 in New Jersey, it was one of the biggest and most expensive stadiums ever built; it was also one of the most energy efficient. When the new facility was built on top of the old Giants Stadium, the stadium signed an agreement with the Environmental Protection Agency, pledging to reduce their carbon footprint.

Although the stadium is twice as large as the old Giants Stadium, the new facility has reduced energy use by 30%. In 2012, the stadium installed a solar panel system capable of generating 350,000 kW hours of electricity per year, enough energy to power 34 homes in a year.

The stadium features an automated lighting control system, energy efficient Low E window coatings to reduce heat gain and the world?s first Certified Green energy efficient restaurant.

5. Gillette Stadium: New England Patriots

The New England Patriots have both solar panels and wind energy systems powering their stadium and the facility?s adjacent shopping center: Patriot Place. The facility has a 1,000 kW solar power system and 700,000 square feet of white painted roofs that reduce the need for air conditioning costs.

The facility has a 3,000 panel solar canopy that not only provides shade to the Patriot Place shopping center, but that delivers 1.1 million kilowatts of power, or approximately 60 percent of the energy used in the complex.

While not all stadiums have made the same strides as these five facilities, take a look at how the rest of the NFL stadiums stack up when it comes to energy efficiency.

6. FedEx Field: Washington Redskins

  • Stadium has 8,000 solar panels to generate up to 2,000 kW of energy
  • Creates enough solar power to provide 20% of energy on home games days and 100% of energy on non-game days
  • Stadium has state-of-the-art solar-powered sculpture named ?Solar Man?
  • Parking lot features ten electric vehicle charging stations

7. Soldier Field: Chicago Bears

  • First stadium in North America to receive LEED- EB Certification for energy efficiency
  • Stadium has replaced all lights with LED lighting
  • Parking lot has free electric car charging stations

8. NRG Stadium: Houston Texans

  • One of only stadiums in the NFL to only use LED lights to illuminate the field
  • New lighting system consumes 60% less energy, at just 337 kW when at full power
  • Stadium parking lot has six electric vehicle charging stadium
  • New stadium renovations include 700 solar panels for upcoming season

 9. Arrowhead Stadium: Kansas City Chiefs

  • Features 308 solar panels on the stadium, training complex and practice facility
  • Total solar panel project generates approximately 29,000 kilowatt hours of electricity per year
  • Has five free electric vehicle charging stations in parking lot

10. University of Phoenix Stadium: Arizona Cardinals

  • One of first stadium in the NFL to have only LED lights, which consumes only 310 kW of energy
  • Implemented new lighting system to cut lighting costs by 75% and reduce cooling costs by 30%
  • Purchased 95,000 kWs of renewable energy from the Salt River Project to power ten home games

11. M&TBank Stadium: Baltimore Ravens 

  • Uses 10,882,000 kilowatt hours of energy per year
  • Has decreased energy consumption by more than 5,000,000 kilowatt hours per year since 2005
  • The first professional outdoor sports facility in the United States to receive a “Gold” LEED Certification from the U.S. Green Building Council

12. Lambeau Field: Green Bay Packers

  • 2014 renovations have saved the stadium more than $100,000 in annual energy costs
  • Stadium features 500 induction lighting fixtures, 11 high efficiency condensing boilers for heat, ENERGY STAR kitchen equipment in all food prep areas
  • Stadium improvements have saved 800,000 kilowatt hours of electricity and more than 65,000 Therms

13. Mile High Stadium: Denver Broncos

  • Facility purchased enough renewable energy through Xcel Energy?s WindSource Program to offset all electrical consumption during home games
  • The Broncos’ Energy Management Program has contributed to a 11% reduction in energy consumption
  • Stadium includes 300 retrofit lighting features estimated to save 1.34 million Kwh per year
  • The facility’s cooling towers reduced energy usage by 200,000 KWh per year since 2010

14. Edward Jones Dome: St. Louis Rams

  • Green energy plan includes using sustainable local energy from solar biomass, wind and geothermal sources
  • Stadium?s Green Game plan offsets 100 % of energy used during several home games
  • Sustainable energy plan offset the cost of all opposing teams to travel to St. Louis
  • Stadium will feature new rooftop solar panels, solar sculpture and a solar-powered trailer from Microgrid Solar during upcoming season

15. Ford Field: Detroit Lions

  • Features energy efficient steam heaters from Detroit Thermal to heat stadium
  • Updated Ford Field saving organization 15 percent in energy costs
  • New design utilized windows for natural light, reducing need for artificial lighting 

16. Mercedes Benz Superdome: New Orleans Saints

  • Stadium?s new 26,000 exterior LED lights only use 10 kilowatts of electricity
  • Entire stadium has reduced energy consumption to 4,600,000, while other stadiums have done better, this marks a major improvement for the facility
  • Superdome features 400,000 square feet of aluminum barrier to improve the stadium?s insulation and reduce heating and cooling costs.

17. Georgia Dome: Atlanta Falcons

  • Has own automated control system to regulate dome’s HVAC
  • Features energy efficient florescent lighting throughout
  • The Dome still has work to do, the stadium?s 1,250 ton air conditioning units still use so much power they can cool 1,666 homes

18. Heinz Field: Pittsburgh Stadium

  • Stadium features separate HVAC and plumbing system to maximize energy savings during specific usage time.
  • New energy-saving infrastructure resulted in $1.25 million in energy saving costs over the first five years
  • Stadium has two electric car charging stations

19. TCF Bank Stadium/New Vikings Stadium: Minnesota Vikings

  • Has 7,500 energy-efficient light fixtures throughout facility
  • Received LEED Certification for energy efficiency
  • Team revealed plans for new energy efficient stadium for 2016 season, complete with full LED lighting and an eco-friendly system designed to consume 75% less energy than traditional stadiums

20. Paul Brown Stadium: Cincinnati Bengals

  • Stadium has been under fire for keeping lights on at all times
  • Energy bills, which are paid by taxpayers, cost $55 per hour
  • Stadium is in the midst of a major renovation to improve its energy efficiency

21. FirstEnergy Stadium: Cleveland Browns

  • First stadium to implement Grind2Energy program, which allows the stadium to generate enough electricity to power a single family home for 18 months
  • Stadium?s program produces enough natural gas to heat 32 homes for a month
  • Stadium?s 2014 renovations replaced the majority of lighting and signage with energy efficient LED lighting

22. Ralph Wilson Stadium: Buffalo Bills

  • First NFL team to use micro-wind turbines for supplemental energy
  • Stadium features its own set of permanent wind turbines underneath field?s scoreboard

23. Lucas Oil Stadium: Indianapolis Colts

  • Stadium is equipped with smart daylight controls and overhead fan system to improve air distribution and minimize energy use
  • Stadium’s retractable roof reduces lighting and cooling costs
  • New energy efficient lights and sensors along with low-flow toilets and a facility recycling program keep the stadium green season-long

24. AT&T Stadium: Dallas Cowboys

  • Stadium uses more than 24,440,000 kilowatt hours per year
  • Peak usage of 10 megawatts of power during peak game times
  • Current green energy plan is attempting to reduce energy consumption by 20 percent per year

The good news for the future of the NFL is that many organizations have plans in place to create entirely new, more energy efficient facilities for their teams. These new endeavors will only help catapult the National Football League’s efforts to reduce their overall energy usage and promote their efforts to become a more environmentally-friendly league.