With the month of October upon us and MLB playoff baseball knocking on the doors, tens of thousands of baseball fans from all over the country will be filing into some of the country?s largest professional baseball stadiums to see their team?s journey on the race to the pennant unfold.

Every season, hundreds of thousands of tickets are sold as fans pile into these stadiums and take advantage of amenities ranging from rooftop bars and Ferris wheels, to full swimming pools. Powering amenities like this is no small feat. In fact, it often takes more than 30 million kWh to power a single MLB baseball stadium for a season, or more than 3,000 average American homes use in a year.

The utility bills for these massive ballparks can cost upwards of $1 million per year. For playoff teams who have more than the traditional 81 home games, that number can go up even more. It takes a lot of energy to power all of the jumbotrons, screens, televisions and restaurants within the stadium, but it doesn?t mean that improvements aren?t being made. In fact, some of the biggest most visited ball parks in the entire country are making major efforts to reduce their energy bills and to become more energy efficient.

Thanks to an effort from the MLB, to participate in the Sports Greening Project, the league has made major efforts to reduce the energy costs associated with facilitating America?s pastime. The MLB was the first professional sports league to partner with the Natural Resources Defense on this project and their efforts have more than paid off.

Here is a look at how some of the biggest stadiums in the country are working to improve their energy efficiency for the millions of fans who enter their ballpark every season.

1. Safeco Field – Seattle Mariners

In 2014, the Seattle Mariners and Safeco Field made history when they became the first MLB team to light up their home field with LED Lights. The field is illuminated with 578 GigaTera light fixtures that are 30% brighter than their old counterparts, but use 50% fewer watts. Just these lights save 784,000 kWh per season and more than $50,000 in energy costs. The organization is now able to save more than $1 million per year, just from reducing their energy and waste costs.

When fans walk between Safeco Field and the facility?s parking garage, chances are they will see the stadium?s new double solar panels. These solar panels can generate 40,000 kWh of power every year; solar power that is poured back into the field?s power distribution grid and that keeps their energy costs way down during both the season and their playoff push.

Efforts like this have helped Safeco Field not only reduce their energy by 25% but to have the lowest energy intensity of any baseball stadium in the MLB.

2. Target Field – Minnesota Twins

Minnesota?s Target Field has certain bragging rights when it comes to their energy efficiency credibility, as the facility was the second ballpark in the United States to ever become LEED-certified and the only one with LEED credentials for both construction and operations.

The stadium was opened in 2010, and in 2011 alone the Marlins managed to reduce their electricity use by over 12 percent with new lighting equipment, even while installing a new video board.

What is perhaps the most impressive move by 2015 playoff hopefuls is their automated lighting system. The system is able to shut down all of the energy-efficient lighting across the facility during certain times of the day. This effort alone has helped save the park nearly $6,000 per year in electricity costs.

The stadium?s office staff members have also done their part in the facility?s major energy efficiency overhaul with daily energy-saving practices that have helped save the park an extra five percent in energy use.

3. Busch Stadium – St. Louis Cardinals

When the St. Louis Cardinals unveiled the new Bush Stadium in 2006, the team made history by being the first team in almost 100 years to win the World Series the same year they opened a new ballpark. However, the history-making didn?t stop there. In just three years after opening, the St. Louis Cardinals were able to reduce their energy use by 24 percent.

Busch Stadium did this by being one of the first professional sports teams to partner with ENERGY STAR. Since partnering with the company, Busch Stadium is now able to operate at a level that is 39 percent better than the national average for most entertainment buildings, even while operating a stadium that mostly operates at night with massive lights.

Most of the stadium?s energy-saving results came from installing occupancy sensors in rooms throughout the building, improving HVAC systems and installing new compact fluorescent lights.

4. Nationals Park – Washington Nationals

The Nationals may be relatively new to the MLB world, but the professional baseball team has already made a mark on the league with their energy efficient stadium. This 41,000 fan stadium was the first facility in professional sports to receive LEED Silver Certification for its new construction.

The stadium also made history when it became the first professional sports stadium to install a green roof. This 6,300 square foot roof is just one of the many additions the Nationals put in their facility to make it more energy efficient. Energy-conserving light fixtures alone helped reduce their lighting costs by 21 percent. This lighting alone is projected to save over $440,000 over 25 years for the stadium.

Overall, since construction, this Washington D.C. stadium has been using 15 percent less energy than comparable professional ballparks; an impressive feat for one of baseball?s newest professional teams.

5. Marlins Park – Miami Marlins

Marlins Park may not seem like a candidate for an energy efficient ballpark. After all, the stadium is home to its own pool and to an 8,000 ton retractable roof. However, this NL East stadium has done a great deal to improve the efficiency of their hometown ballpark.

The nearly 37,000 fan stadium is also LEED Gold certified, thanks to its energy efficient efforts. The entire stadium including its lighting, heating and cooling systems, electrical components and mechanical gears have been revamped in a move that has reduced the facility?s energy costs by 22 percent.

As for that massive retractable roof, thanks to the stadium?s advanced regenerative drive system it only costs around $10 to open or close.

6. AT&T Park – San Francisco Giants

AT&T Park, home of the San Francisco Giants made history when it became the first ballpark in Major League Baseball to have its own solar array. The team installed this solar system in 2007. The 122 kilowatt system generates enough solar power to supply 5,200 homes. For the Giants, it is enough to power their new massive scoreboard for a full year.

The solar panel system was introduced at the 2007 All-Star Game and is the first system of its kind to be introduced to a Major League Baseball Stadium. The system includes 590 different modules spread around three locations across the park.

The facility also installed their own point-of-use lighting control system in all of their restrooms, concession stands and storage spaces.

7. Fenway Park- Boston Red Sox

Fenway Park may be the oldest stadiums in professional baseball, with an opening date of 1912, but it doesn?t mean that today the stadium isn?t one of the most energy efficient. The Red Sox took their energy efficient practices into their own hands when they completed a complete energy audit on their facility.

Today, the park has new LED lighting throughout their stadium and 28 solar panels, positioned across their dugout. This solar array alone provides 37 percent of the energy needed power the stadium?s water heaters. The stadium, which won the EPA New England Environmental Merit Award in 2008 for its sustainability initiatives.

In the corner of the stadium, Fenway has their now famous Coca-Cola Corner completed with massive Coca-Cola light-up sign. After their 2010 audit, the team replaced 1059 lights in the sign, which use 80% less power than traditional incandescent bulbs.

8. Citi Field – New York Mets

On top of Citi Field lies a 10,000 square foot green roof, which has been instrumental in insulating the stadium and keeping heating and cooling costs, particularly on cool winter nights during end-of-season play.

When Citi Field added their new temperature control system throughout their facility, they were able to reduce energy consumption by 50% throughout the stadium. This system works in accordance with the facility?s lighting control system which operates light fixtures, ad panels and televisions throughout the stadium.

When fans sit down to enjoy a game at Citi Field this playoff season they can enjoy the game knowing the field has a 100 percent alternative energy offset for their electricity use, in a plan that will extend all the way until June 2016.

9. Progressive Field – Cleveland Indians

The Cleveland Indians have also taken a swing at improving their stadium?s energy efficient parties with several major updates to Progressive Field. The 43,000 person stadium installed its own solar panel system, and was the first American stadium to have a solar array of its size. This 42 panel system generates more than 8000 kilowatts of power. The stadium also hosted an experimental wind turbine provided by Cleveland State University in an effort to keep their energy costs down.

The stadium isn?t just thinking big either, they are making small changes as well. The Progressive Field staff is making their own energy efficient efforts in their office habits and together the baseball stadium has successfully reduced its overall energy usage from 23 million kWh per year to 17 million.

10. Miller Park – Milwaukee Brewers

The Milwaukee Brewers may have a massive retractable roof on top of their home stadium, but that hasn?t stopped Miller Park from holding official LEED certification. The famous ballpark has updated everything from their electrical power systems and lighting to their HVAC systems to make their more energy efficient.

One of their biggest efforts came with adding a new energy-efficient HD scoreboard; which uses 50% less electricity than the stadium?s old scoreboard. The 2015 playoff bound team may be known for having one of the most unique stadiums in all of baseball, but with the recent energy efficient changes to Miller Park, fans are now getting to enjoy one of the most energy efficient parks as well.

If you get a chance to see one of these exciting post-season games live at one of these thrilling professional sports stadiums, you may be surprised to find how far they have come in being more energy efficient.