NREL: Partner Forum Helps Cement Partnership Between NREL, Dallas Fort Worth International Airport

Each year at its annual Partner Forum, the National Renewable Energy Laboratory (NREL) assembles leaders from industry, government, and academia to discuss emerging sustainability and renewable energy trends. In 2018, the forum planted a seed that would quickly flourish into a highly impactful partnership between Dallas Fort Worth International Airport (DFW) and NREL.

A U.S. Department of Energy (DOE) push for national laboratories to use supercomputers for transportation projects, in combination with a great relationship between DFW and NREL, begat an inaugural project titled Athena. Athena, funded partially by DFW, partially by DOE, and including Oak Ridge National Laboratory, set out to provide decision support and actionable insight surrounding transportation flow and aimed to mitigate risk for long-term planning at the airport.

The research team accomplished that by creating what is called a digital twin. With the help of powerful DOE supercomputers, researchers took data sets from data loggers placed on vehicles driving around DFW, combined that with data provided by DFW, and essentially created a working copy of the airport’s traffic. This allowed researchers to simulate various scenarios and accurately forecast ideal solutions.

The Athena team accomplished what it set out to do but, in the process, discovered the potential for much more. Since Athena’s completion, NREL has provided DFW with world-class expertise and cutting-edge technology to overhaul many of the airport’s most critical operational capabilities at the system level—steps necessary for DFW to meet its well-advertised 2030 net-zero carbon emissions goals.

“NREL has the capabilities of helping airports understand complexities and improve their decision-making under uncertainty while identifying opportunities for innovation,” said Robert Horton, DFW vice president for energy efficiency and sustainability. “Our success is based on our ability to articulate a clear vision of what we’re trying to accomplish, built around our sustainability north stars. Without an organization developing well-outlined and ambitious long-term goals, stakeholders will find it difficult to understand your intended outcomes or leverage the powerful resources NREL brings to bear.”

NREL and DFW have committed to working from the ground up at the system level, designing upgrades and implementations that can integrate intelligently across the board.


While working on Athena, the team identified several opportunities to explore carbon emission reduction and optimization strategies. Ken Kelly, an NREL researcher who worked on the Athena team, said that when he arrived at DFW to begin work on Athena, he and a colleague made some critical observations about bus traffic between the terminals and the rental car center. He said they observed the busses running with the same frequency and in the same numbers regardless of the number of passengers on board.

“They were just running, and it didn’t matter that only one or two passengers were getting on or off at that time of day,” Kelly said. “We observed them continuing the route regardless. So, once we were further into Athena, we thought it might be interesting to route the busses in a way that would save energy and possibly even reduce the number of busses required.”

The team spoke with DFW and began looking at the whole system, noting it boiled down to more than just the vehicle and how it operates. They started looking at the cost, availability of the vehicles, and infrastructure requirements.

“We hatched an idea to take a more comprehensive look at electrification,” Kelly said. “We wanted to begin with the DFW-owned vehicles—the whole fleet, including sedans, light-duty vehicles, snowplows, and so on.”

This all became a new project called EV Blueprint.

The team is starting with airport-owned vehicles but would optimally then move to airline-owned vehicles and ultimately to personally owned vehicles and infrastructure. Kelly said they are moving through the project in phases and just kicked off the first five months, planning on a one-year project initially. There is hope it will extend beyond the first year.

Photo of electric vehicles connected to chargers in a parking garage
NREL is helping DFW electrify vehicles and vehicle infrastructure at the airport. Photo by Dennis Schroeder, NREL
A Net-Zero System Needs To Be Energy Efficient Too
DFW first became operational in early 1974. In 2021, it was ranked the second busiest airport in terms of passengers globally. However, nearly 50 years after it opened, parts of the massive, 17,000-acre, seven-runway airport with its own ZIP code and postal service designation are starting to appear their age. This opened the door for collaborative, energy-efficient upgrade solutions. One notable example was the central plant, responsible for heating and cooling the airport.

“Big campuses require heating and cooling at the same time year-round,” said NREL researcher Otto VanGeet. “When those overlap—when there are needs to do both heating and cooling—the classic way is to run chillers to make cooling water and reject the heat to cooling towers, and run natural-gas-fired boilers to make steam and pump it out to campus.”

VanGeet said the solution was to run heat recovery chillers (heat pumps) that could generate both heating and cooling water at the same time, calling it the core of the solution.

“It sounds simple,” he said, “but it’s actually very complicated when you get to giant campuses. It was a great solution that will result in roughly a 90% carbon reduction. Now, what they’ve done was take almost all their natural gas and replaced it with heat pumps, which saved water at the same time. It becomes much, much harder when you get into the details—taking miles and miles of steam piping and redoing the whole campus for lower-temperature hot water, all while keeping the airport running, but the takeaway is an estimated 87% carbon reduction and a significant water reduction as well.”

NREL also played a key role in providing design advice for DFW’s new Integrated Operations Center (IOC), an undertaking that resulted in both a Best Projects Award in Engineering News-Record Texas & Louisiana’s 2021 Best Projects competition and an American Association of Airport Executives 2021 Airports Going Green award for Outstanding Sustainability Infrastructure Development. The IOC meets FEMA storm shelter standards and is prepared to absorb requirements from future airport infrastructure.

Reengineering the central plant to take a big bite out of the airport’s carbon footprint and designing the IOC with such a forward mindset were massive steps, but where energy efficiency was concerned, the team did not stop there. A newer project in the portfolio—Morpheus—has already started working to interact with that plant to increase efficiency in building operations around the campus.

NREL researcher Korbaga Woldekidan said Morpheus is a great demonstration platform for what grid-interactive buildings can do. Morpheus is a collaborative research and development agreement, also known as a CRADA, and is partially funded by DOE, which has a vested interest in grid-interactive buildings. Like Athena, Morpheus utilizes digital twin technology. However, it is an optimization project that taps into a commercial-off-the-shelf (COTS) digital twin platform from Willow Inc. that DFW procured.

“Digital twins are expensive,” Woldekidan said. “Instead of just using this as is, we add extra functionalities, we can make them more affordable, and if we make them more affordable, more airports can adopt those technologies. Morpheus reads/writes building control points from/to the building automation system (BAS) through the Willow COTS.”

Similar to how Athena was able to simulate highly accurate traffic solutions, Morpheus affords researchers the opportunity to simulate building operations to find the most efficient routines to implement. The scope is twofold, optimizing the central plant’s operation to make it as energy efficient as possible and improving the operation and service life of the air handling units (AHUs) in Terminal D by application of automatic fault detection and diagnostics.

“Most digital twins don’t provide this service,” Woldekidan said. “This might be the future and could increase the adoption of digital twins by quite a bit. This is not just research. We’re working to deploy previously conducted research. DOE really wants to move in that direction, and in that regard, this is really impactful.”

NREL and Its Partner Forum Historically Advance Technological Capabilities
The process, as much as the insights, can potentially move energy integration forward. Horton called DFW’s partnership with DOE and NREL significant because it allows the airport to use data to forecast future scenarios that allow DFW to make smarter investments of time and money for infrastructure.

“You’re starting to see the impacts of urbanization with communities encroaching on the airport’s footprint,” Horton noted. “What that means to us is a heightened sensitivity between the community and the airport. From a social or community perspective, we must operate responsibly and balance the social, economic, and ecological demands. So the research the labs provide is critical for informing our investments.”

As communities close in on airports and airlines begin to search for sustainable solutions that lower carbon emissions, airports are beginning to look at infrastructure needs required to support such operations. Preparing a grid to absorb the draw of electric aircraft charging is no small matter. Neither is regulating those operations, but NREL has come alongside both airports and primary regulatory agencies, such as the Federal Aviation Administration, to assist with guidance as responsible oversight evolves in new areas.

Horton said collaboration is essential, and his two key takeaways are that the industry tends only to look out about 3–5 years. In contrast, NREL specializes in looking beyond that and helps de-risk future investments virtually before real-world applications. In addition, the industry does not have the financials to conduct the level of research NREL provides before investing in new infrastructure and technologies.

“The second is uncertainty—asking the challenging questions,” he said. “What are the challenging questions the industry is tackling? You hear from DOE and others what the most pressing industry challenges are. If you don’t have clear business objectives and goals and if you can’t articulate them clearly, you will focus on myopic issues instead of large, complex concerns. That’s the strength of NREL—to put the pieces together and see the big picture.”

In August 2022, NREL will again pull together industry, government, and academia leaders to network, explore potential partnerships, and discuss critical emerging trends in renewable energy at its Partner Forum. The 2022 Partner Forum centers around sustainable aviation.