Salt Lake City Int’l Enhances Airside Sustainability With Electric Ground Support Equipment

The new Salt Lake City International Airport (SLC) that opened in September 2020 features many enhancements to save energy and reduce the facility’s carbon footprint, including charging stations for electric ground support equipment.

One reason sustainability is so top-of-mind is that SLC is located in a valley prone to inversions—a weather pattern that occurs when a dense layer of cold air becomes trapped beneath a layer of warm air, as if it’s under a lid. These inversions, coupled with emissions from vehicles, industry, agriculture and other sources, can cause harmful pollutants to accumulate and linger.

Kevin Staples, SLC’s environmental programs manager, notes that aircraft are often singled out as the big polluters at airports, but fleets of diesel-powered ground support equipment constantly moving around the airfield also have a negative impact on air quality. “We want to do everything we can to help the Salt Lake Valley and the air pollution issues,” says Staples.

Moving to alternative fuels was a change that could have a dramatic positive effect on air pollution in the valley, he adds. And airport leaders recognized that designing and building the new airport presented an ideal opportunity to begin a full transition to electric ground support equipment, providing immediate, impactful health benefits to the community as well as workers who operate the equipment. “We knew electric GSE [ground support equipment] was the future,” Staples says. “We were lucky because we were building a completely new airport.”

To work toward its goal of eliminating all equipment that burn fossil fuels, SLC began to transition its shuttles to compressed natural gas in 1991 and operates under a Green Fleet Action Plan. Currently, the airport’s shuttle fleet operates on 100% renewable natural gas, and it is transitioning to a fleet of more than 30 electric Ford F-150s and Transit vans for Operations and Maintenance departments. A new airline use agreement signed in April 2014, required its airline partners to transition to electric ground support equipment within 18 months of the new terminal opening. “We needed to give them notification and give them time to ramp up,” explains Staples.

The Transition

Prior to the policy change and mandate, there were just two electric ground support vehicles at SLC; the rest operated on gasoline and diesel fuel. Airport leaders knew the transition would not be easy, but the benefits to the environment, community and airlines heavily outweighed those challenges, Staples says.

Specific goals to reduce SLC’s greenhouse gas emission include:

• procuring 100% renewable energy by 2040;
• transitioning to entirely electric or other zero-emissions vehicles by 2040; and
• achieving an 80% reduction in greenhouse gas emissions per passenger by 2040, compared to 2009 levels.

Staples explains that there are three classifications of greenhouse gas emissions. Scope 1 are those directly influenced by the airport, such as airport shuttles; Scope 2 are emissions from the purchased electricity to operate the terminal; and Scope 3 are emissions from aircraft. The conversion to electric ground support equipment is a helpful way to assist the airlines reduce their Scope 1 emissions, while improving our Scope 3 emissions, Staples says. “If we put in the charging stations, we’re having a direct influence on their emissions.”

Airport leaders understood it was important to add infrastructure necessary to support the transition and provide sufficient charging stations as the new equipment began to arrive. Under its latest airline use agreement, SLC provides the charging infrastructure and the airlines supply their own ground support equipment, including bag tugs, belt conveyors and pushback tractors.

When designing the charging infrastructure, SLC placed all of the charging units against the concourse exteriors to enhance safety. The airport invested in a multi and dual vehicle charging system powering at 30kW, 40kW and 80kW. Primary and secondary charging systems allow airlines to smart charge their electric ground support equipment.

Bag tugs are charged under the new concourses, where diesel tugs previously operated. Eliminating the need for a ventilation system that diesel tugs require was a huge cost savings for the airport when building the new airport, notes Staples. Only baggage tugs with lithium batteries can be charged in unventilated areas.

Delta now uses electric cargo loaders at Salt Lake City Int’l.

When SLC’s project was being planned, electric charging was relatively new at airports, so there were few design examples or standards to reference. Now that the new facility is operational, there are some modifications that would make use easier, but “we were doing the best with what we knew at the time in terms of design and installation,” Staples reflects.

Networking with other airports and sharing ideas has been beneficial throughout the transition. “I still learn a lot from other airports, whether it’s operations, maintenance or engineering,” he relates.

As of early October, fully 96% of the ground support equipment at SLC is now electric. The 478 pieces include aircraft tractors, baggage tractors and belt loaders. There are 442 chargers and an additional 94 slated for installation.

While some airlines ended up purchasing new equipment to meet the airport’s requirement, much of the equipment was already in operation at other locations and relocated to SLC. Staples estimates that Delta Air Lines, the dominant carrier at SLC, owns and operates about 90% of the ground support equipment at the airport. “They really got on the ball and started transitioning right off the bat,” he comments.

New Policies and Procedures

In 2018, Menzies Aviation delivered nearly 240,000 gallons of diesel fuel to SLC’s airline partners. Last year, that number dropped to 106,641 gallons, resulting in an estimated reduction of 1,100 metric tons of heat-trapping carbon dioxide.

Adding electric charging infrastructure means the airport is now a fuel provider of sorts—something it hadn’t been in the past. To fulfill that new role, SLC employs two full-time workers to maintain and operate the airside charging stations for ground support equipment and the landside stations for airport vehicles. Airport staff members and airline personnel received comprehensive training to reduce safety hazards and equipment damage. “It was something they’d never experienced before—it was all brand new to them, so we had to work with the airlines to make sure they were training their folks,” Staples says. “That first year, there was quite a learning curve.”

One aspect of ongoing training addresses battery acid spills. “It’s all so new,” Staples emphasizes, adding that the electric charging equipment and procedures prompted changes to the airport’s Safety Management Systems.

But SLC’s team has risen to the occasion, he reports. “I’ve watched the maintenance side really grow in terms of understanding the new technology.” In addition to operating and maintaining the equipment, frontline personnel have been a valuable asset in gathering data and offering suggestions for improvement.

Everything from the cable to plugins is SLC property. “We thrive on owning and operating our own equipment,” Staples says. “We really want to be hands-on and take ownership of what we have.”

Balancing Sustainability and Resilience

Equipment shortages and supply chain issues associated with the Covid-19 pandemic created hurdles that prompted the airport to extend its original compliance deadline for airlines. “We were very understanding about those issues,” Staples says. Airport leaders consider the current 96% conversion rate to be a tremendous environmental win and look forward to full compliance soon.

The next significant environmental change for airlines at SLC is switching from lead batteries to lithium. Although this will be a difficult stretch for some airlines, Staples notes that it will ultimately benefit them with better technology. As of Jan. 1, 2024, any new vehicles put in service at SLC must have lithium batteries. During the transition period when both types of batteries will be used, a safety inspection program uses red tags to identify equipment with lead acid batteries and green tags to identify lithium batteries. The color-coding system is designed to prevent lead acid batteries from being charged in unventilated areas—a practice that would compromise the health and safety of employees working in baggage rooms.

To further its mission of sustainability while ensuring resilience, SLC receives off-site solar energy from the Elektron Solar Project in neighboring Tooele County. The 100MW solar farm is expected to offset about 90% of the airport’s electricity usage. On-site renewable energy is sourced from solar arrays on SLC’s Fire Station 11 and 12, which use 100% and approximately 80% solar energy, respectively.

As other airports contemplate switching to electric ground support equipment, Staples emphasizes that communication with tenants throughout the transition is paramount to help them along. “And owning our own charging equipment has been the best thing we’ve done,” he adds.

Staples is optimistic about the significant strides SLC and its partners are making toward sustainability. “It’s a wonderful time because we all have the same goal—airlines, airports, concessions. We’re all on the same path to be net zero by 2050.”