Hartsfield-Jackson International Airport’s director of sustainability, Michael Cheyne, envisions airport solar arrays, an airport composting center and electric vehicle charging stations.

But for the world’s busiest airport, it’s not easy going green.

Challenges abound in the many other efforts the Atlanta airport is making to improve its environmental standing, and it has experienced a series of setbacks over the past couple of years.

A much-vaunted recycling program dubbed GreenSortATL launched in 2009, then failed because the recyclable material was too contaminated with garbage.

Last year, an airport composting initiative stalled after the closure of a composting center the airport had planned to use.

Then this year, the rollout of electric vehicle charging stations was delayed amid financial problems at the firm that makes the stations.

And as the airport plans even more ambitious projects such as the solar arrays and its own composting center, there’s no firm source of funding, meaning the projects are contingent on getting a grant, public-private partnership or other source of money.

To be sure, the airport has already made moves such as converting parking shuttle buses from using gasoline to more environmentally friendly compressed natural gas. It also has added water-bottle refilling stations on the concourses, installed water-saving fixtures in restrooms and placed energy-saving LED fixtures in parking garages.

But other major airports already have more advanced recycling and composting programs than Atlanta does. Chicago’s airport system even has green vegetative roofs and a bee apiary.

And even if Hartsfield-Jackson is successful at launching its environmental initiatives, airports are still known as giant spewers of greenhouse gas emissions, huge producers of waste and enormous energy consumers.

At Hartsfield-Jackson, officials in 2009 heralded an ambitious recycling program featuring cans throughout the airport labeled with a GreenSortATL logo and the phrase “You Trash. We Sort. It’s Recycled.” The idea was that people would dump all their refuse into one bin and recyclables would later be separated from the garbage.

It didn’t work, and the program was canceled. Too much of the recyclable material was contaminated by discarded soft drinks, thrown-away food and other garbage.

“I think people were trying to be aggressive in doing the best we could,” Cheyne said. “Until you go through the process … you have bigger aspirations than reality.”

Since then, there has been no broad recycling program for travelers — a glaring gap for the world’s busiest airport. Maintenance workers do recycle cardboard, and Hartsfield-Jackson has been running limited pilot projects in the international terminal and Concourse T using separate trash and recycling bins. But there is still a minimal amount of recyclables recovered from consumers — about 1 percent to 2 percent of waste — due to garbage still being mixed in with recyclables, Cheyne said.

People are “not used to seeing the containers here,” Cheyne said. “We need to change habits, which takes a while.”

The airport plans to eventually try a new program using more than 300 single-stream recycling bins — which can handle a variety of recyclable materials — at a cost of as much as $200,000, with operational and maintenance costs of about $150,000 a year. Cheyne said one possibility to prevent garbage from being thrown in with recyclables is to employ containers with smaller openings for cans and paper. Ultimately, Hartsfield-Jackson’s goal is to divert 90 percent of waste from landfills by 2020, he said.

Allen Hershkowitz, a senior scientist with the Natural Resources Defense Council, believes airport and airline recycling programs are largely underdeveloped.

“Every business should be recycling,” he said. “There’s no excuse for throwing out valuable plastic bottles, valuable paper, valuable aluminum.”

But Hershkowitz also said, “You don’t want to keep changing the design of the program because that could be confusing to the public.”

One of the airport’s biggest proposed environmental projects is called Green Acres ATL’s Energy Park Campus, which would include compost curing piles, odor control biofiltration towers and separation of recyclables. There also could be greenhouses, a combined heat and power station, an area for anaerobic digestion, an education center and solar arrays.

It’s partly aimed at fulfilling an airport plan that was waylaid last year. In its massive concessions contracting process last year, Hartsfield-Jackson officials included a provision calling for concessionaires to use compostable utensils and packaging, and to separate materials for transport to composting facilities.

After Greenco Environmental closed a composting facility last year in Barnesville that Hartsfield-Jackson had planned to use, the airport put the composting requirement for concessionaires on hold.

“There is no compost facility in the Atlanta area. That is hard for me to even say,” Cheyne said. “We have given a bit of a waiver for concessionaires to separate organics because there’s nowhere to put it.”

It will likely take at least until 2015 to complete an airport composting facility.

If built, Green Acres could compost yard trimmings for the city of Atlanta to use in parks or urban gardens, and it may eventually be able to take compostable trays and utensils from Atlanta Public Schools — though the city and school system may need to pay for the processing, Cheyne said. That’s because federal aviation funding guidelines prevent the diversion of airport funds to non-airport uses. Because of that, the composting facility also likely wouldn’t be able to give compost away to the public, he said.

As part of an effort to address the greenhouse gas emissions from vehicle traffic at the airport, Hartsfield-Jackson had planned to put in 18 electric vehicle charging stations this summer — but ECOtality, the electric charging station maker the airport had struck a deal with, ran into financial problems and filed for Chapter 11 bankruptcy this month.

Those aren’t the only environmental programs Hartsfield-Jackson has struggled with.

The airport is also connecting a water box built on top of the international terminal to the airport’s irrigation system. The water box was originally intended to harvest water to use in restroom facilities in the terminal, but “it was decided it was too expensive” to run separate systems for potable and nonpotable water, Cheyne said. “So rather than let the box sit there not being used, we’re turning it into a storage container,” adding a pump and using it to irrigate landscaping, he said.

Hartsfield-Jackson also plans to pursue a solar panel project next year that would produce 6 megawatts of power — enough to power six large department stores. Plans to build the project through a Georgia Power program were put on hold this year because the airport procurement process would have taken too long to meet the utility’s deadline, Cheyne said.

Separately, the airport plans to seek Federal Aviation Administration funding to help pay for a $14 million solar array producing 4 megawatts of power on top of the airport rental car center next year. The airport has been analyzing issues with glare to make sure the solar arrays will not affect air traffic controllers or pilots.

Hershkowitz believes airports have a hefty responsibility in trying to improve their environmental profile.

“Airplanes in particular are a big contributor to greenhouse gas emissions,” he said, “so if any area had an obligation to try to be responsible and bring those impacts down, it’s airports.”