Incorporating Tactical Energy Storage into War Reserves: DLA’s Vital Role in Sustaining Strategic Assets

Abstract

War Reserve Materiel (WRM) is critical to minimizing supply chain disruptions inherent in contested logistics. For over sixty years, forward-deployed, prepositioned war reserve materiel (PWRM) has enabled rapid response to contingencies and strengthened deterrence against emerging threats. However, as the U.S. fighting force relies increasingly on technologically sophisticated and environmentally sustainable equipment, a critical gap exists in the current WRM framework: the absence of batteries and Tactical Energy Storage (TES). While batteries generally refer to individual units used to power small devices, such as flashlights, TES describes a larger system designed to provide reliable, portable regenerative power in demanding situations, ensuring greater durability across a range of extreme environmental conditions and changing needs on the battlefield.¹ As technology advances and the demand for clean and renewable energy continues to grow, this omission warrants reconsideration.

This paper explores the importance of integrating batteries and TES into WRM to enhance operational capability, reduce risk, and secure a decisive advantage for today’s modernized, electrified, and sustainable force. It describes the impetus for TES and battery inception, explains governing policies, and illustrates the WRM gap created by the changing character of war in the 21st century. This paper highlights the evolving landscape of military energy needs necessitating available energy storage technologies required on a distributed, multi-domain battlefield. Finally, this paper provides recommendations to the Department of Defense (DOD) and Military Services to integrate energy storage into the PWRM to posture Combatant Commanders for successful sustainment of highly technological Large-Scale Combat Operations.

Introduction to War Reserve Materiel

The 2022 National Security Strategy (NSS) states that, “aligning military strategy with available resources is crucial to national security.”² In light of global threats posed by technologically advanced adversaries including a disruptive Russia and China’s pacing threat, the 2022 National Defense Strategy (NDS) charged U.S. Military Services with advancing national defense goals through integrated deterrence, campaigning, and building enduring advantages^.3 Each requires a globally distributed, ready, and modernized force.

To be ready for the next fight, Combatant Commanders are tasked with ensuring resources are aligned to provide immediate support to the Joint Force when and if conflict breaks out. Therefore, the Military Services maintain mission-essential equipment, supplies, munitions, and prepositioned stock around the world as part of our global posture to support strategic objectives and maximize operational readiness in response to immediate threats and contingencies. This materiel is defined as War Reserve Materiel (WRM) or prepositioned WRM (PWRM).

PWRM varies across the Military Services based on the theater-specific needs of Combatant Commanders. It provides initial equipment, repair parts, supplies, and munitions to support weapon systems and military forces during contingency operations until replenishment processes can be established to meet demand.⁴ USAF Instruction 25-101 further explains the two components of PWRM: starter stock and swing stock. Starter stock lasts until resupply; swing stock, which is aligned against more than one contingency,⁵ is “intended for use until sustainable logistical lines of communication are established in a region that has transitioned from competition to crisis or conflict.”⁶

Since its Cold War era inception, PWRM has evolved and expanded globally as needed to deter new threats in multiple regions. Today, PWRM remains critical to realizing integrated deterrence in the current, contested logistics environment because it is strategically located globally in each area of responsibility and reduces the time required to achieve an operational capability or an operational effect. PWRM creates efficient and timely resourcing by minimizing reliance on strategic airlifts, alleviating backlogs caused by inadequate supply lines, and ensuring responsive sustainment for Combatant Commanders during the initial phases of military operations.

PWRM governance is designed to address regional threats and support forward-positioned military equipment while maximizing resource efficiency. Each theater’s PWRM stockage list and levels are customized based on DoD guidelines and doctrine. Individual Combatant Commanders determine specific operational requirements based on theater plans and in accordance with the Chairman of the Joint Chiefs of Staff Instruction (CJCSI) 4310.01⁷, which establishes logistics planning guidance for PWRM application during the full spectrum of contingency operations. DoD Instruction (DoDI) 3110.06 outlines the responsibilities for managing WRM across various DoD components, following the prioritization guidelines set forth in the CJCSI 4310.01D for assigned, allocated, or apportioned forces.⁸ DoDI 3110.06 mandates the acquisition and maintenance of WRM inventories during peacetime, ensuring sufficient resources will be available to achieve and sustain strategic objectives, as directed by the Secretary of Defense (SECDEF) in the annual Defense Planning Guidance.

Successful management of PWRM involves both appropriated funds from Congress and defense working capital funds that purchase and manage inventories to stabilize item supplies and prices.⁹ The Military Services are responsible for managing and funding their own WRM. However, they rely on the Defense Logistics Agency (DLA) for certain DLA-managed items critical to military operations, and DoDI 3110.06 directs DLA to coordinate with the Military Departments to contract, stock, or perform storage and distribution functions for WRM. “To maximize the use of existing funds, the military departments should minimize WRM requirements with alternative sources of support, this includes coordinating with other military departments and agencies, including the DLA. The DLA coordinates with the military departments to contract, stock, or perform storage and distribution functions for designated WRM and contingency retention stock in coordination with the CJCS to support mission requirements.”¹⁰ The military departments, who own the responsibility to equip forces, validate WRM requirements to achieve the greatest practical flexibility and responsiveness to a full spectrum of regional contingencies while minimizing DoD investment.¹¹ While Combatant Commanders and Military Services play a key role in determining what prepositioned materiel is required in times of crisis and conflict, the SECDEF ultimately retains the authority to authorize the release of PWRM to allocated forces for a military operational employment.

Management and maintenance of PWRM is a team sport across the joint enterprise. All Military Services maintain PWRM stocks worldwide in a variety of settings as a comprehensive global power projection strategy. The Army, Navy, Air Force, and Marine Corps each have their own stocks, either afloat or ashore, serving as mobile power projection platforms to deter adversaries from threatening global security while enabling rapid response capabilities.¹² The Military Services collaborate with the DLA to manage the contracting, stocking, and distribution of designated PWRM to effectively meet their mission requirements. Among many other examples, two historical instances of this Joint Force collaboration highlight its effectiveness. During Operation Desert Shield in 1990-1991, PWRM pre-staged in the Central Command Area of Responsibility enabled the delivery of armored units to the Persian Gulf. This material equipped Marine Corps forces one month before the arrival of similar units shipped from the United States. In 2022, the Army rapidly issued PWRM, referred to as Army Prepositioned Stock (APS-2), to the 1st Armored Brigade Combat Team deploying in support of the NATO Response Force following Russia’s invasion of Ukraine.¹³ Having the PWRM available not only eliminated the burden of time and assets on strategic airlift, but also extensively reduced the estimated time to issue and respond to Russia’s aggressions.

Understanding the Gap in PWRM

Although examples of PWRM supporting global operations indicate the program’s effectiveness in countering past threats, the NDS stresses the importance of adapting to evolving geopolitical, economic, and technological advancements that alter the character of war. As the threat environment changes and the equipment in the U.S. inventory modernizes, PWRM must evolve to keep pace with changing operational requirements. Already, the Military Services are fielding more unmanned systems, electrifying vehicles, and adding sensors and sophisticated communications suites to existing equipment.¹⁴ The blistering pace of technological innovation is changing the way we fight and creating significant gaps in current PWRM materiel allocations. PWRM must modernize to successfully support the multi-domain style of warfare emerging on the battlefields of Ukraine, Gaza, and Haiti, and expected in future conflicts.

In addition to new technology, three aspects of modern war challenge current sustainment constructs: decentralization, mobility, and disrupted lines of communication. According to retired Marine Corps Commandant, General David Berger, “The biggest problem facing the Navy and Marine Corps’ plans to deter great power competitors is how to supply a widely distributed maritime force in a contested environment.”¹⁵ He called for “smaller, highly mobile Marine expeditionary units capable of operating in multi-domain environments.”_¹⁶ The Marine Corps is not alone in recognizing this need and its inherent challenges. To support in a contested environment, the Army is reconfiguring its collection of vehicles and facilities used to deliver supplies to sustain military operations – known as a “logistics tail” – by experimenting with hybrid power, autonomous aircraft, watercraft and vehicles, and artificial-intelligence-enabled predictive logistics tools.¹⁷

A Joint Force operating in highly mobile, decentralized formations in a contested logistics environment demands a new support framework. This way of fighting requires accessible and sustainable energy sources to fuel the fight until secure lines of communication can be reestablished. This brings us to the most significant shortfall in PWRM to support a transforming military: the lack of modern energy sources, including batteries and battery hybrid power systems for military use – known as TES^.18

Disruptions in power supply can have cascading effects, impacting everything from specific tactical missions to broader operational plans. Both energy sources offer advantages and disadvantages: fuel-powered energy involves combustion or chemical processing, typically offering higher energy density but with environmental off-sets. Battery-powered energy stores electrical energy in chemical form, offering greater efficiency and cleaner energy but lower energy density and longer recharge times.¹⁹ With advancements in technology and logistics contested in all domains, the demand for TES continues to rise because fuel-powered options are heavier and less mobile at a time when almost every weapon system requires some level of battery power and power regeneration on the battlefield. However, there are currently no TES sources allocated to PWRM, highlighting a critical need to adapt our reserves to meet modern warfare and energy requirements.

The Evolving Landscape of Military Energy Needs

According to the Hamilton Commission on Securing America’s National Security Industrial Base, “Advancements in energy storage, such as NG [Next Generation] lithium batteries, will be key in the DoD's reorientation for great power competition.”²⁰ The commission was created by the Hudson Institute, a Washington. D.C-based research think tank, to examine sectors critical to American national security and propose policy recommendations to reduce dependence and advance U.S. leadership in these industries. Energy storage offers operational continuity, logistical efficiency, power management and rapid response capabilities to support increased modernization needs related to battery power requirements. Most modern weapon systems, which include equipment ranging from drones and lasers to tanks and submarines, now require battery electrification and recharging^.21 “Batteries power everything from unmanned systems to electromagnetic warfare systems.”²² Despite this, fuel remains the predominant energy source in military operations; for every gallon of fuel used in the recent Afghanistan war, seven gallons were required for transportation. Focusing war reserves solely on fuel, rather than including energy storage solutions, channels limited resources (financial and storage) into a high cost, high volume, and easily targetable commodity that does not satisfy the requirements of modern warfare. Alternatively, smaller, cost-effective TES and batteries enable distributed formations with electrified fleets to recharge equipment from a reduced logistics footprint that decreases adversary detection. Thus, updating war reserves to include a balanced energy portfolio is critical to sustain modern warfare.

Lighter designs, fast-charging capabilities, and extended charge capacity battery innovations enable the shift from fuel as the military’s primary energy source. A relevant case for immediate and available energy is Ukraine’s defense during Russia’s invasion. To bolster its  defensive capabilities against Russia, Ukraine required rechargeable TES/batteries to power the Javelin, a man-portable anti-tank missile designed for precision strikes against armored vehicles, bunkers, and other targets. Over an 18-month period, DLA provided a total of 60,000 batteries for the Javelin, enabling Ukrainians to repel a numerically superior Russian force from seizing the capital city of Kyiv^.23 This example reinforces the ability of TES to enhance flexibility and rapid response in multi-domain operations, minimizing the risk of extended and contested supply lines by ensuring the consistent availability of power for weapon systems. The lack of Tactical Energy Storage in PWRM creates a critical gap, hindering the availability of immediate and accessible energy during urgent situations.

The Rise of Renewable Energy

Introducing TES and batteries into PWRM not only addresses a key gap in forward-positioned energy reserves, it also supports the military’s fight against another threat identified in the NDS – climate change. As geopolitical dynamics shift and the focus on renewable energy and climate policy increases, there is a growing emphasis on next-generation (NG) weapon systems supported by sustainable energy sources. This approach enables end-to-end management from raw materials access and processing to recycling and reclamation, fostering a more sustainable and resilient energy ecosystem.

Integrating renewable energy sources into military operations offers several key advantages. Renewable energy enhances the use of advanced technologies on the battlefield; ensures resilience when fossil fuels are limited; and provides cost efficiencies through rechargeable and environmentally friendly energy sources. Additionally, the shift to renewable energy increases energy security by reducing reliance on overseas sources and manufacturing while countering China's dominance over the battery supply chain. Energy security is a critical issue tangential to TES that will be addressed in a future paper. While storing batteries does present some risks due to the varying shelf-lives of different products depending on battery type and chemistry, effective battery management strategies can help minimize wastage. As battery technology advances, shelf-life will extend, further reducing risks and supporting more sustainable and reliable energy solutions for military operations.

The DoD is rapidly transitioning from traditional fuels to renewable energy, signaling the increasing need for TES and batteries^.24 The Military Services leverage the Battery Energy Storage System (BESS) to move, store, and augment fossil fuels to reduce energy disruptions^.25 The Defense Innovation Unit currently partners with the Air Force, Navy and commercial industry to develop advanced mobile and stationary BESS solutions.²⁶ “Another renewable energy effort, the Extended Duration for Storage Installations (EDSI) Project, aims to create backup power systems for DoD installations and operational energy platforms that can be mobile or stationary. The EDSI Project goal is to increase operational availability and minimum power threshold for batteries, bases and battlefield energy.”²⁷ These efforts support the 2022 NDS priority to “build a resilient Joint Force and defense ecosystem.”²⁸

Current Efforts to Evolve Energy Supply and Storage

DoD leadership recognizes the technological, operational, and sustainable importance to invest in TES and batteries. In April 2022, Dr. Kathleen Hicks, the Deputy Secretary of Defense, directed an increase in energy supportability and a reduction in energy demands across all capability development activities.²⁹ To optimize investments, the DoD continues to drive Department collaboration and compels the Military Services to standardize batteries across major weapon systems. Dr. Hicks noted that “It is vital to improve standardization. The standardization of batteries will enable distributed operations in contested environments, contribute to interoperability with Allies and partners, help streamline acquisition and minimize supply chain vulnerabilities.”³⁰

In addition to battery standardization efforts, whole of government teams across the DoD are actively working toward new battery solutions to address emerging threats and limit operational vulnerabilities^.31 As the DoD’s only Logistics Combat Support Agency, DLA remains focused on supporting TES on the battlefield and currently supports the Services with over 4,000 various types of batteries composed of various chemistries and technologies.

DLA plays a pivotal role in battery innovation, seeking opportunities to reduce risk within the battery supply chain. One of DLA’s notable programs is the Battery Network (BATTNET), a designated Operational Energy Program under the Defense ManTech Program. BATTNET collaborates with other government and industry partners to develop high-performance battery technology solutions. A few of BATTNET’s accomplishments include low-cost battery manufacturing innovations and material production and development of an integrated lithium-ion-based power system to increase runtime, eliminate legacy equipment, and mitigate obsolescence.³² BATTNET's advancements in new manufacturing designs and processes for lithium-ion and bipolar lead-acid power sources enhance capabilities like operational reach and endurance in U.S. military tactical vehicles, aircraft, and equipment.

DLA and the Military Services share a critical role in driving transformation to ensure combat effectiveness extends beyond the tactical level.³³ To that end, DLA manages a diverse battery portfolio from the ubiquitous AAA battery powering wildland firefighting efforts among millions of examples to high-energy thermal batteries supporting the Intercontinental Ballistic Missiles of the Nuclear Triad. Each battery type, regardless of size, cost, or power, is a vital energy source enhancing the effectiveness of military operations and bolstering response to national security crisis and emergencies. To support military departments and Combatant Commanders, DLA invests annually in high-demand energy storage and batteries. The agency maintains a two-year stock-on-hand (SOH) for the top 53 lithium-ion battery requirements and an average of six months SOH for 6TAGM lead-acid batteries, which power more than 100 critical military weapon systems. DLA responds to approximately 15,000 demands each month for the 6TAGM alone.³⁴

These highly technical efforts support a broader DoD effort to modernize its energy supply. However, DLA-maintained battery SOH is only designed to meet minimum surge requirements, meaning current supply availability is insufficient for the forecasted high-volume demands of a modern, large-scale conflict. While DLA's on-hand supply of batteries has historically met immediate operational requirements, addressing emerging needs in the context of multi-domain operations and contested logistics necessitates a reevaluation of DoD battery and TES stocks. A failure to invest in a largely renewable energy inventory introduces significant risk to future combat effectiveness. Therefore, it is essential for the Military Services to consider adding TES and battery systems to Service PWRM inventories.

Conclusion and Recommendations

Energy is a critical enabler of military capability. The 2023 Operational Energy Strategy dictates, “To ensure Joint Forces have access to the energy needed to fight and win while operating within contested environments, the Department will reduce operational energy demand, diversify our energy sources, improve supply chain resilience, and enhance the enterprise-wide visibility of energy supply and demand.”³⁵ The DoD relies on energy resilient forces and  weapon systems to fulfill its mission in a highly advanced technological modern operating environment, and PWRM is critical for operational readiness in achieving the DoD’s strategic objectives, especially when global crises inevitably occur and require rapid DoD actionor mobilization. Contested logistics and the complexities of energy use present significant challenges to maintaining energy security.³⁶ As the DoD focuses on transformation to sustain and strengthen U.S. deterrence against our pacing threat, PWRM stocks require reevaluation, realignment, and expansion beyond the current commodities and categories. Foremost, integrating TES and batteries into PWRM strategy would enhance the military's deterrence posture by aligning energy resources with the needs of rapidly evolving weapon systems technology, while efficiently and sustainably supporting decentralized and highly mobile modern military formations. To echo the DLA Director’s recent challenge to operate in a contested logistics environment, we don’t have to have everything, everywhere, all at once, but we should have the things we need at the right place and the right time.³⁷