It all started with the Cleveland Indians baseball team, the first American League team to install a solar energy array in 2007.

For the Indians, the clean, “green”, alternative energy resource was the result of a cooperative effort between the Indians and Green Energy Ohio, or GEO, and resulted in an 8.4-kilowatt solar array on the south-facing upper deck of Jacobs Field, above Carnegie Avenue and I-90. GEO is the nonprofit organization that liaises Ohio’s (solar) manufacturers and providers.

Indians’ management chose GE panels for reliability, and the 42-panel array (with additional cooperative input from The Cleveland Foundation, the State of Ohio Department of Development, and Doty and Miller Architects) will also feature a kiosk showing real-time electricity production via Flash software and an LCD display. The monitor will also provide information on solar electricity technology, historical data on energy production, and greenhouse gases avoided by the system.

Also in 2007, the San Francisco Giants worked with regional utility Pacific Gas and Electric Company to install a solar energy system at AT&T Park comprised of 590 Sharp solar panels delivering as much as 122 kilowatts of electricity for the utility’s San Francisco ratepayers.

But it isn’t just baseball. In 2007, the Philadelphia Eagles football team partnered with PPL Corporation to install three single-axis tracking solar panel assemblies totaling 10 kilowatts to deliver electricity for the Eagles work and practice facility.

And in 2009, the Phoenix Suns basketball team threw the switch on a 194-kilowatt solar energy system via design-build solar energy firm EI Solutions Inc. (the systems integration arm of Energy Innovations, Inc., located in California). The system was financed by San Mateo, California-based Tioga Energy, which continues to operate it under a power purchase agreement, or PPA.

The system utilizes 1,125 Suntech panels, installed on about 18,000 square feet of the fifth level of the US Airways parking garage, the Suns home field. The solar photovoltaic panels will reportedly produce 331,233 kilowatt-hours each year, preventing the production of 238 metric tons of carbon dioxide by regional utility Arizona Public Service, or APS. This is the same as taking more than 45 cars off the road, or planting almost 6,100 trees.

At Denver’s Pepsi Center, which hosts the Denver Nuggets basketball team, the Colorado Avalanche (an NHL hockey team), the Colorado Mammoth lacrosse team, and the Colorado Crush AFL foot team, the installation of 52 rooftop solar panels on the arena's Blue Sky Grill restaurant provides 13,641 kilowatt-hours of electricity per year to the facility, and avoids 9.42 metric tons of carbon dioxide, the greenhouse gas most commonly implicated in climate change.

The privately-owned stadium also buys 11,000 megawatt-hours of renewable energy each year from Sterling Planet, which replaces all of the facilities conventional energy purchases.

The greening isn’t confined to solar, of course. By the middle of March, the Seattle Mariners will be playing at a transformed field – one that uses efficient LED lighting to operate of the field’s largest scoreboards, reducing electrical use by more than one million kilowatt hours per year.

But solar is a major part of the move toward a smaller environmental footprint, and the movement is only beginning, as witness a recent survey by ProGreenSports which notes that 80 percent of North American pro sports teams plan to increase environmental and sustainability programs, and 60 percent have already formed internal environmental monitoring teams to find ways to reduce energy use and prevent waste and pollution from their activities and arenas.