The parking’s not free but the juice is! Earlier this week Denver International Airport (DIA) announced that it will install 10 electric vehicle charging stations this fall allowing EV owners to charge their vehicle while away—for free. Considering that they’re already paying an arm an a leg for parking, they might as well get something for free.

The airport is offering the charging stations in response to an increase in spotting more EVs there. “We have seen an increase in the number of customers who drive electric vehicles to the airport and plug them into existing electrical outlets in the garages,” said Kim Day, Denver’s Manager of Aviation. “These new charging stations are more convenient, safer and designed to work specifically with electric and plug-in vehicles. The airport continues to evolve to meet the needs of our customers and support the city’s Greenprint Denver sustainability initiative.”

The Telefonix, Inc. Level 1 (110-volt, slower) chargers that are being installed take about eight hours to fully charge an EV, according to DIA. They are compatible with most EVs and plug-in hybrids, like the Chevy Volt, the Nissan Leaf and the plug-in Toyota Prius. Five charging stations will be installed on the West side and five on East side of airport. The spots, which are designated for EV and plug-in hybrids only, will be on level 1 between rows E and F in each garage.

“This is one of the first major public installations of commercial Level 1 electric vehicle charging systems in the United States, and I can’t think of a better place than at Denver International Airport—which already has a reputation as being one of the greenest airports in the world,” said Allen Will, director of business development and programs of Telefonix, Inc. “This project will set a new standard for airports that want to provide the best possible customer experience for drivers of plug-in electric vehicles.”

Level 1 EV chargers use standard 110-volt electricity as opposed to Level 2 or even Level 3 chargers. Level 2 and Level 3 chargers use 240-volt or higher electricity to fast charge EVs’ battery packs. The Level 1 chargers were chosen for DIA because they will charge most EVs in eight hours and the average stay in the parking lot is 1.4 days and they’re less expensive than Level 2 or Level 3 chargers, like Tesla’s Superchargers, which can charge a Tesla vehicle enough in a half hour to drive 150 miles.

The new EV chargers at DIA aren’t the first EV chargers at the airport’s parking, however. Canopy Airport Parking opened in 2010 and has six EV charging stations that offer Level 1 and Level 2 charging. Canopy also is powered by solar and wind.