First in a two-part series on how the military can meet targets for lowering greenhouse gas emission.
In early 2022, the U.S. Army announced a commitment to attain a 50% reduction in Army net greenhouse gas (GHG) pollution by 2030, aiming for net-zero Army GHG emissions by 2050. It’s an aggressive goal, part of President Biden’s overarching federal sustainability plan for lowering emissions across the government.
Military leaders realized that one of the most expensive problems standing in their way is military vehicle idling. After conducting a fleet-wide analysis, military fleet managers discovered their vehicles spend approximately 80% of runtime idling. The DoD has especially singled out Family of Medium Tactical Vehicles (FMTVs) as needing idle reduction.
With estimates showing the military burned through 82.3 million barrels of fuel in 2022, such a high idle time means substantial and unnecessary fuel usage. That’s a huge negative impact on military sustainability, both environmentally and economically.
Simply turning off vehicle engines could enable a path to meet the military’s emission-reduction goals while simultaneously extending vehicle life and reducing fuel expenses.
The issue of establishing a more sustainable military doesn’t need to create a political disagreement. The right technology can address concerns of financial responsibility plus environmental sustainability without compromising safety, readiness or ease of operation.
Energy technology limitations facing the U.S. military
Given the current state of energy storage and infrastructure, the technology for a fully electric vehicle isn’t feasible in real-world military applications.
Even the best lithium-ion (li-ion) technology is a fraction of the energy density of gasoline or diesel. That means liquid fuels hold much more energy (about 25 times more) than li-ion batteries in the same amount of space, relatively. The number of batteries necessary to drive equivalent distances to an internal combustion engine vehicle would use up much more space and add thousands of pounds of weight. Density isn’t a problem for small, efficient EV passenger vehicles, but for an FMTV carrying equipment, armor and weapons systems, it’s prohibitive.
Many commercially available medium duty EV trucks have a range of 100-200 miles on a single charge. While this is plenty for local transit or deliveries, it’s not nearly enough for the field where bases are few and far between. And in developing countries, charging infrastructure is virtually nonexistent.
In the military, access to adequate supply can be the difference between life and death. As Dwight D. Eisenhower once said, “You will not find it difficult to prove that battles, campaigns and even wars have been won or lost primarily because of logistics.”
If one thing could make the military overlook range limitations, it would be adequate infrastructure to support more frequent fleet charging. But, as anyone familiar with EVs can attest, the faster the charger, the more power it requires, the more expensive it is, and the more difficult it is to maintain.
The specialized infrastructure necessary for charging a fully electric solution makes it impractical anywhere apart from a stable grid. The inability to charge while in a remote location is an enormous barrier, but even for localized use, the power capacity necessary for a large fleet would require grid-level infrastructure changes.
For example, suppose a base needs to simultaneously charge 100 EVs at the end of a standard nine-hour shift on 350kW chargers. This requires an instantaneous draw of 35MW — enough capacity to power about 30,000 homes.
Supply Chain Limitations
When innovating technology for field use, military engineers have access to a specific list of approved components to work with. These are products they’ve tested rigorously and know to be both safe and up to military quality standards. Lithium-ion is no exception.
The lithium-ion currently approved by the military for use is in limited supply. Like anything else with a low supply and high demand, prices are impacted. While the automotive industry has access to lithium-ion chemistries costing approximately $150 to $200 per kilowatt hour (kWh), the military pays closer to $2,400 per kWh.
That means it costs the military over 12 times as much for the same amount of power due to lack of automotive supply chain access. Additionally, this limited access to the “approved” lithium technology will limit innovation potential and slow the military’s development of new idle-reducing technologies being driven by the automotive industry. This must be solved through testing and policy changes if the military is going to be successful in carbon reduction.
While the military’s current vehicles burn fuel and create emissions, they’re still functional machines with substantial life left. The cost to replace a fleet of hundreds of thousands of vehicles with full EVs would be astronomical, even if done over time. For example, the US military has over 60,000 FMTVs in service all around the world. Vehicle emissions aside, these are perfectly functional, reliable vehicles trusted to do their jobs.
By adding an auxiliary hybrid system to their idling vehicles, the military can maximize the cost efficiency of emission reduction while rapidly upgrading their entire fleet of vehicles.