NREL Experts Accelerate Electrification of Department of Defense Nontactical Fleets

NREL Experts Accelerate Electrification of Department of Defense Nontactical Fleets

One of the Nation's Largest Fleets Is on the Path to Going Electric Thanks to NREL Tools, Analyses, and Experience

As electric vehicles (EVs) continue to grow their share of the market, several federal agencies are transitioning their own fleets to EVs, too.

At the U.S. Army, for example, 27% of the new or replacement light-duty vehicles (like sedans, minivans, and pickup trucks) ordered in 2022 were EVs or plug-in hybrids, up from just 1% the year before. To maintain the momentum, they needed to know they were making the right decisions on how many EVs they needed and how to manage their charging needs. So, the Army team and other agencies within the Department of Defense (DOD) turned to the National Renewable Energy Laboratory (NREL) for tools, analysis, and guidance.

"The Army has expertise, resources, and funding for fleet electrification," said NREL's Leidy Boyce, a research engineer and federal fleet electrification expert. "But having that additional set of eyes-especially those who can offer decades of experience on charger deployment challenges-is what our partners look for when they come to NREL."

'We Connect the Dots'

Crosscutting expertise, advanced tools, longtime experience, and responsiveness make NREL's EV and charging infrastructure deployment experts the go-to fleet electrification resource. In a single year from 2021 to 2022, NREL researchers helped increase EV acquisitions in the federal fleets nearly sixfold.

"It's more difficult for DOD agencies to manage the many elements of EVSE [electric vehicle supply equipment] rollout than a private fleet company because these agencies are huge and have a critical responsibility for protecting the country that has to be their primary objective," said Cabell Hodge, NREL's Analysis and Vehicle Deployment group manager. "Therefore, they look to experts to consult on these matters, and our team fits the bill."

NREL researchers have worked with DOD since 2016 when they began helping the Navy, Marine Corps, and Army with site assessments to determine the best locations to install EVSE on its bases. More recently, NREL has engaged in complex projects to assess the potential for bidirectional charging as a resilience strategy with the U.S. Army National Guard, built a web tool for the entire federal government to complete EVSE site assessments remotely, and begun exploring the charging needs for privately owned vehicles at every Army base in the country.

"Working with NREL provides assurance that it will be done right the first time," Boyce said. "More than likely, we have done it before, we have the skills, and we can connect the dots between technologies and deployment strategies through data."

Tools for Everyone

To achieve the nearly sixfold growth in federal fleet EV acquisitions without visiting every federal site, NREL developed tools to identify easy-to-electrify vehicles, group vehicles by location, identify charging station needs, and generate cost estimates for the chargers.

These tools include the Zero-Emission Vehicle Planning and Charging (ZPAC) tool, which was developed in partnership with the U.S. Department of Energy Federal Energy Management Program in planning for future zero-emission vehicle acquisitions, as well as NREL's marquee EVI-X Modeling Suite of Electric Vehicle Charging Infrastructure Analysis Tools.

In the last two years, DOD's Environmental Security Technology Certification Program (ESTCP) funded the NREL team to assess where EVs can provide backup power and develop an EVSE site-assessment tool and cost estimator called EVI-LOCATE for federal fleets.

"NREL has been a great partner in DOD's efforts to electrify our nontactical vehicle fleet," said Tim Tetreault, the Installation Energy and Water Program manager with ESTCP. "In addition to the tools they've developed, like ZPAC and EVI-LOCATE, their expertise and analytical capabilities are helping the department keep pace with the rapidly changing technology and evaluate how the department can potentially gain new capabilities with the transition to EVs."

"Developing EVI-LOCATE required our team to tap into expertise from many disciplines," said Ranjit Desai, an electric vehicle charging researcher at NREL. "We relied on the lab's expertise in fleet operations and on how federal fleets work, our team's understanding of the duty cycles and operations of DOD fleets, and our analysis capabilities such as financial modeling-all that had to come together to build the tool."

The NREL researchers also had to be prepared to pivot. As part of developing EVI-LOCATE, the team conducted stakeholder engagement to understand how agencies using the tool needed it to work. DOD fleet managers shared that they needed to transmit EVI-LOCATE results-site recommendations and cost estimates-to a specific government form to request funding from agency leadership to install EVSE. To streamline the process, they wanted EVI-LOCATE to generate results formatted to easily be inputted into the form, rather than the existing generalized report output. In response, the NREL team is crafting a solution to get the tool's output directly into the form's format, making the tool even more applicable and valuable for DOD's specific use case.

The federal fleets team is currently creating a public version of EVI-LOCATE-expected to roll out later in 2024-that will let people anywhere plan for commercial charging stations.

Beyond providing analysis and tools for planning zero-emission vehicle acquisitions and charger installation, NREL researchers use their experience with EVSE deployment to provide recommendations for DOD on which combination of charger power levels is appropriate. Level 1, Level 2, and direct-current fast charging all have different levels of power, charging speeds, and requirements for installation. Deciding what distribution of chargers to use depends on when EVs are being used, the length of each vehicle's shift, and the number of shifts, among other factors. NREL experts are helping DOD identify the most cost- and energy-efficient mix of chargers.

Additionally, NREL is helping DOD assess how their sites will have to adapt to prepare for increased electricity demand from more EVs. Adapting could mean adjusting charging strategies to balance demand over periods of time or expanding the electrical distribution grid. A potential NREL-developed tool can help entities like DOD select the strategies that work for them.

One of the reasons Hodge enjoys working with DOD is that the resulting analyses and tools can propel the entire industry forward.

"The work tends to be on the cutting edge," Hodge said. "DOD wants us to conduct critical analysis such as using bidirectional chargers as backup power for critical loads. The analysis and tools we develop for them can then be scaled and shared to support many others interested in EV adoption."

Desai agreed.

"The DOD fleet is one of the largest fleets in the United States," he said. "If DOD can transition their nontactical vehicles to zero emissions, that is a high-profile success story for vehicle electrification."

Learn more about NREL's transportation and mobility research. And sign up for NREL's quarterly transportation and mobility research newsletter, Sustainable Mobility Matters, to stay current on the latest news.