The electric car revolution is arriving. Last year US President Joe Biden outlined a target to have 50 percent of all new vehicles sold in the United States zero-emission vehicles by 2030. The goal is ambitious, but achievable, and industry has already been moving aggressively toward electric and hybrid vehicles without government urging. Leading automotive manufacturers like GM and Stellantis (the parent company for Jeep, Dodge, Opel, Fiat, Peugeot, Maserati, and others) have already committed tens of billions of dollars toward developing electric and hybrid vehicles in the next several years. Volkswagen has committed to making electric cars account for 40 percent of its sales by the end of the decade. And Ford announced that in 2023 it will spend more on electric vehicles than internal combustion engine vehicles for the first time in its 119-year history. There have been so many recent electric and hybrid vehicle announcements that Elon Musk joked he was “waiting for my mom to announce one.” Leaders in the military are clamoring for more electrification of tactical and nontactical vehicle fleets as well. The US military needs to take advantage of this electrification trend and follow fast in adopting the best new technologies. Doing so will not only reduce its reliance on petroleum fuels; it will increase the lethality of the force. However, determining how best to take advantage of electrification requires careful consideration of the full range of electric vehicle options. This is not a binary decision between hastily embracing an all-electric future or stubbornly maintaining a fossil-fuel status quo. Our future military readiness demands that we rise above such harmful simplification of a complex issue and give it the careful consideration it deserves.

Three Kinds of Electric Vehicles

One of the most important nuances often missed is that the term electric vehicles actually covers a range of propulsion systems that fit into three main categories. Each of these has distinct advantages and disadvantages. The first, and most well known, is the all-electric vehicle. In the consumer market, Teslas are examples of all-electric vehicles. This type of electric vehicle has a battery and an electric motor. The battery is charged when the vehicle isn’t in use and it powers an electric motor. These vehicles are completely emissions free, as long as the electricity used to charge them was from renewable sources—though there are environmental concerns about sourcing the raw materials required for battery manufacturing. They drive extremely efficiently, accelerate quickly, and are dangerously quiet. But despite the advantages, the technology is not ready for tactical vehicles because it requires incredibly heavy and bulky infrastructure for power generation and charging—with the exception of niche roles in reconnaissance and small unmanned aviation, which need shorter range and lower acoustic signatures. More innovative applications are arriving every day but the physics of the underlying limits on battery technology are not expected to change any time soon, significantly limiting the potential of all-electric vehicles for tactical use. However, the military has around 170,000 nontactical vehicles, mostly the cars and trucks it uses on military bases, that would be ideal for electrification. The Army has already committed to fielding an “all-electric light-duty non-tactical vehicle fleet” by 2027 after its successful pilot programs and the Marine Corps has been making strides toward electrifying its nontactical wheeled vehicle fleet at some bases and investing in charging stations as a cost-saving measure.

The second type of electric vehicles are parallel hybrids like the Toyota Prius. In parallel hybrids, vehicles have both an internal combustion engine and a battery that are independently connected to the wheels through a mechanical coupling. These vehicles are in a sense more reliable than all-electric vehicles because they have both electric motors and internal combustion engines. Because of this, however, they are also more complicated and do not have the efficiency of a fully electric vehicle. The batteries are also usually too small to power travel over long distances and these vehicles can best be thought of as internal combustion engine vehicles with an assist from batteries to give them higher efficiency.

The third type of electric vehicle is the series hybrid like the Chevy Volt. These vehicles have electric motors that are run either by batteries that can be charged externally or by a petroleum-fueled generator. Series hybrids have all of the efficiency advantages of a fully electric drivetrain but can also be fueled with petroleum if needed. And the ability to charge the batteries from onboard fuel means this type of vehicle’s total energy capacity is much deeper than that of an all-electric vehicle. Series hybrid vehicles recharge their batteries while on the move, rather than requiring the vehicle to be stationary for many hours, as with all-electric vehicles. Since their mobility comes from electric motors, they have all the power and torque benefits of a fully electric vehicle. Series hybrid vehicles should be the next step in tactical ground vehicles for the military. They offer ground forces immediate benefits that contribute directly to enhanced lethality: nearly silent operation, lower fuel consumption through higher efficiency, higher instantaneous torque for towing and acceleration, and fewer maintenance requirements. Having large batteries and efficient electricity generation aboard all tactical vehicles will also enable easier integration with new sensors and especially directed-energy weapons that require the high, instantaneous power output that batteries can provide. Increasing requirements for electrical power at the small-unit level for radios, drones, tablets, lasers, computers, and sensors will demand better distribution of energy than current vehicles can provide.

Hydrogen fuel cells can also be combined with batteries and electric motors. The US Army has experimented with GM’s ZH2 fuel cell–powered truck, which has most of the same benefits as an electric vehicle but runs on hydrogen instead of a battery charge. Fuel cell technology is rapidly evolving alongside battery technology and is another option the military should closely consider for tactical vehicles. The US Air Force already operates prototype hydrogen-fueled, nontactical vehicles in Hawaii. These developments are indicators that series hybrid power train designs are much more future proof than other vehicle architectures, because their petroleum fuel tanks and onboard generators can be configured to run on another fuel (such as hydrogen) or even swapped out with other power generation systems (like fuel cells).

Where the Military Is Today

The US military is the largest institutional consumer of petroleum fuels on the planet, using as many as 4.2 billion gallons of fuel each year. The military pays a premium for its fuel—the Defense Logistics Agency spent over $9 billion dollars on fuel in 2019. Expenditures went down significantly during the pandemic but in 2022 Congress had to appropriate more money for fuel purchases not once, but twice for a total of $3 billion extra. Furthermore, the ongoing war in Ukraine and OPEC’s commitment to reduce production will keep fuel prices high for the foreseeable future. The price of delivering fuel to remote outposts can cost the Pentagon as much as $1,000 per gallon, according to the Army. And dollars aren’t the only way the military pays for fuel; it also pays for it with the blood of service members. Between 2003 and 2007 one out of every eight casualties in Iraq came as a result of protecting fuel convoys.

The military’s addiction to petroleum fuels is a liability. Convoys are vulnerable to attack by insurgents and enemy forces. Oil tankers in transit can be attacked and fuel refineries targeted. Fuel can also be leveraged as a political tool: in one such case, Pakistan closed a critical border crossing into Afghanistan, keeping convoys full of fuel and bound for the NATO mission idling on the other side of the border. And logistics requirements only increase in large-scale combat operations. A US armored division might require up to half a million gallons of fuel per day. Russian logistics failures and the infamous “40-mile-long convoy” that sat stalled on roads outside of Kyiv further highlight how difficult fuel logistics are. At the same time the use of silent, electric tactical bikes by Ukrainian sniper teams shows how such technologies can make troops more lethal.

In part because of this, the Army is leading the way and investing in pilot programs for electric and hybrid vehicles. The Army’s new Climate Strategy set a 2027 target to field an all-electric light-duty, nontactical fleet and a 2035 target for both a full all-electric nontactical fleet and hybrid tactical vehicles by 2035. To meet these goals Oshkosh Defense has already demonstrated a hybrid Joint Light Tactical Vehicle, while GM has shown off an all-electric version of its Infantry Squad Vehicle and a hydrogen fuel cell–powered version of its Chevy Colorado marketed at the military. BAE has been working on a hybrid Bradley Infantry Fighting Vehicle for several years.

The Marine Corps also needs to get onboard with hybrid vehicles. The Marine Corps specializes in expeditionary and amphibious operations, which make it even more vulnerable to getting cut off from fuel supplies than the Army. The commandant of the Marine Corps, General David Berger, has repeatedly emphasized that logistics are the “pacing function” for future Marine Corps operations in the Pacific. Other Marine leaders have been even more specific, arguing that “fuel is the pacing commodity.” New Marine concepts like Expeditionary Advanced Base Operations will stress Marine logistics as Chinese military leaders have made clear that they would target US logistics vessels, with fuel shipments certainly included. Reducing sustainment requirements is critical for Marines.

The Joint Light Tactical Vehicle

The Joint Light Tactical Vehicle (JLTV) is the military’s replacement for the venerable Humvee—officially the high-mobility, multipurpose, wheeled vehicle, or HMMWV—which has been in service for decades. The primary advantage of the JLTV is that it was designed to provide increased protection for troops against improvised explosive devices, but as currently designed, it may not be ideal for future conflicts. The Army and Marine Corps intend to buy as many as sixty-five thousand JLTVs to replace the bulk of their light tactical vehicle fleets in the coming years and the new vehicles are expected to remain in services for decades. For comparison, the HMMWV first entered service in the early 1980s and is expected to remain in service indefinitely, alongside the new JLTV. The ongoing JLTV acquisition is the ideal place to start shifting to hybrid tactical vehicles because of the size of the buy, and because the JLTVs will likely remain in service for a generation or more.

The military should prioritize acquisition of series hybrid JLTVs to take advantage of commercial developments in electric and hybrid vehicles, while simultaneously forging ahead with the development of a hydrogen fuel cell–powered variant. Oshkosh Defense, the maker of the JLTV, has already developed a hybrid model that it claims can improve fuel economy by over 20 percent and eliminates the need for towed generators. Committing to major purchases of hybrid JLTVs is an immediate step the military can make toward improving battlefield lethality and reducing petroleum fuel dependence.

The Critics

Unfortunately, critics of efforts to electrify military vehicles have decried them as politically motivated and overly focused on climate change, which they argue should not factor into planning to meet the military’s core mission. But they ignore the obvious tactical and financial benefits of electrification. Shifting the military to electric and hybrid vehicles shouldn’t be controversial; it will help make our forces more lethal and save the military money. Yes, it will also help address the climate crisis, but that is just one of the advantages, which also extend to helping wean US forces off their dependence on foreign oil, especially in critical theaters like Europe, where prior to Russia’s invasion of Ukraine the US military was using the energy equivalent of nearly half a million barrels of Russian oil per year, according to an analysis by Brown University.

But there are real challenges to electrification and hybridization of the military’s ground vehicles. Batteries are obviously a critical component, and they are overwhelmingly manufactured outside the United States and rely on lithium, cobalt and other raw materials that are also largely sourced and refined outside the United States. This creates a weak and brittle supply chain in peacetime and could cut off the defense industrial base from critical supplies completely in a major conflict. Increasing production of consumer electric vehicles will reinforce the critical battery sector but could also compete with production for the military. Several new domestic battery manufacturing plants are projected to open over the next few years, which will be critical for supporting domestic electrification. Similarly, expanding sources of lithium and other key materials are crucial for supporting the electrification of the military’s vehicles. The government needs to aggressively support these two essential industries to make electrification viable for the military.

Battery transport safety is another risk of electric vehicles that needs to be addressed. All services, but particularly the Army and Marines, transport large numbers of tactical vehicles by ship, and even some through airlift. Battery fires add new risks to that movement. However, these ships already transport even more dangerous cargoes like munitions and jet fuel—so establishing safety protocols for vehicle batteries is well within the realm of possible. The Navy has already established a dedicated battery safety office to meet this need.

As US industry leaps headlong into the electric vehicle market, the military, especially the US Army, is taking early steps on its own electric and hybrid vehicles. They provide clear tactical benefits as well as reducing fuel requirements and, as the technology improves, the benefits will only increase. But the military needs to make sure that it is pursuing the right technology in the right places. Nontactical vehicle fleets, which operate largely from domestic bases and can rely on charging infrastructure at US bases, should be electrified as soon as possible. This is a cost-saving measure with environmental benefits. Tactical vehicles should, starting with the JLTV, be hybridized with series hybrid configurations as they are modernized. The troops that use them will benefit from better local power generation for everything from directed-energy weapons to charging radio batteries, nearly silent drivetrains, less maintenance, and greater efficiency. Switching the military to hybrid vehicles is a lethality measure with logistics benefits. The military will also save money and use less fuel. Failure to electrify the military’s ground vehicles will leave them an anachronism in an age where industry has transitioned to more capable and more efficient technology. It’s time to follow industry and fast track DoD vehicle electrification.

Walker D. Mills is a Marine Corps infantry officer in training to be an RPA pilot. He is a nonresident fellow at Marine Corps University’s Brute Krulak Center for Innovation and Future War and a nonresident fellow with the Irregular Warfare Initiative. He holds a BA in history from Brown University and an MA in international relations and modern war from King’s College in London.

Ryan Wiechens is member of the Technical Staff in the Energy Systems Group at MIT Lincoln Laboratory, a Department of Defense federally funded research and development center in Massachusetts. He leads MIT LL’s development of modular and scalable tactical microgrids, hybrid power systems, and vehicle electrification. He holds a BS in mechanical engineering from Northwestern University and an MS in mechanical engineering from Stanford University.

The views expressed are those of the authors and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.

Image credit: Lance Cpl. Alison Dostie, US Marine Corps

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This material is based upon work supported by the Department of the Air Force under Air Force Contract No. FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Department of the Air Force.