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Energy on Demand

The availability of instant, usable energy may revolutionize the way combat operations are supported in the future battlespace.

Editor’s note: This is the fourth in a series of five articles on themes for future logistics innovation identified by the Army Logistics Innovation Agency’s Futures Group. Each of the articles describes plausible future advances in technology and business processes that may significantly improve logistics effectiveness and efficiency. Together, they bring an advanced look at some amazing possibilities for Army logistics. The fifth article is titled Prediction and Cooperation.

The generation, storage, and distribution of energy on the battlefield have always been essential to sustaining military operations. This is especially true today as evidenced by the challenges facing our forces in multiple training and operational situations across the globe. Army and Marine Corps units participating in Operation Iraqi Freedom (OIF), for example, have experienced shortages of supplies, including certain types of lithium batteries that power myriad communications and electronics systems. Fuel distribution in the early months of OIF was not a problem because the U.S. military had the luxury of extraordinary planning and rehearsal time. However, future battles in other regions may not offer the same preparation time or the same access to, and abundance of, energy sources.

It is important to point out that a recent study indicated that 70 percent of the convoys in Iraq transport fuel—ideal targets for our enemies. Transporting enormous quantities of fuel over vulnerable supply lines equates to an Achilles heel for an otherwise unmatched Army.

In an increasingly nonlinear battlespace, especially as portrayed in joint operating concepts for the 2015–2025 timeframe, meeting the needs of widely distributed, energy-hungry military forces will demand innovative solutions. The proliferation of high-energy weapons in the battlespace will only contribute to increased energy requirements and, without proper long-range planning, may handicap future forces. While solving today’s logistics challenges is the most immediate concern, logisticians must plan ahead for the changes in doctrine, organization, training, materiel, leadership and education, personnel, and facilities (DOTMLPF) that will be necessary as a result of scientific and engineering advances in energy sources.

Shrinking the military services’ dependence on fuel would reduce transportation requirements and decrease the number of Soldiers placed in harm’s way. This could be achieved by, for example, increasing the efficiency of military equipment, thereby reducing energy usage and distribution requirements. However what if instant, usable energy were available at the point of effect (where and when it was needed)? We refer to this as energy on demand (EoD).

The goal of EoD is to reduce operation and sustainment costs dramatically and to minimize significantly the need to transport some types of energy sources to the battlefield. While the tendency is to think in terms of vehicular propulsion requirements, the future battlespace is likely to involve extraordinary energy demands for all types of military equipment and weapon systems. EoD presupposes maximum energy conversion efficiencies, ubiquitous energy storage, extreme energy densities (as compared to today’s typical energy densities), onsite energy production and use, and networked energy distribution. (Energy density is the amount of energy stored in a given system or region of space per unit volume or per unit mass.) The idea is to produce platform and system energy in amounts that will support sustained combat operations under all conditions.

In this article, we talk about some of the exciting possibilities that scientific and technological advances toward EoD will have on future Army logistics. We present some basic concepts of energy generation, storage, and distribution and offer a glimpse of future networked energy grids that may revolutionize the way energy is distributed to support sustained combat operations under all conditions.

EoD Functions

EoD encompasses generation, storage, and distribution. Energy generation generally refers to the transformation of chemical energy, solar energy, biomass energy, and other forms of energy into electrical energy. Energy generation also seeks to maximize the efficiency of energy conversion.

Coupled closely with energy generation is energy storage, the goal of which is maximize energy density. Renewable energy generation from wind and solar energy sources, for example, is intermittent because of either atmospheric conditions or time of day. Advances in storing energy from such renewable sources will allow supply at the point of effect.

Energy distribution will play an increasingly important role in fulfilling the energy demands encountered on tomorrow’s battlefield. Distribution will be achieved with smart grids that can meet the long-term energy needs of a deployed force and with flexible, plug-and-play, self-regulating microgrids capable of interfacing with each other. Military energy distribution grids of the future will maximize commonality and interoperability while emphasizing battlefield flexibility and distribution.

Energy Generation and Storage

Fuel cells. Fuel cells are devices that convert the chemical energy of a fuel (such as hydrogen, natural gas, methanol, or gasoline) and an oxidant (such as air or oxygen) into electricity. In principle, fuel cells operate like batteries. However, unlike batteries, fuel cells are designed for continuous replenishment of the reactants consumed. Continuous long-term operation is feasible as long as a fuel and an oxidizer are supplied to the cell.

Fuel cells, like batteries, have two electrodes (metal plates)—a positively charged anode (fuel electrode) and a negatively charged cathode (oxidant electrode). In addition to the electrodes, fuel cells have an ion-conducting material called an electrolyte sandwiched between the electrodes. The electrolyte carries charged particles from one electrode to the other. Finally, there is a catalyst that speeds up the reactions at the electrodes.

Currently, six types of fuel cells either exist or are being researched. Fuel cells are classified by their electrolyte material because this material determines what chemical reactions take place in the cell, the catalysts required, the operational temperature of the cell, and the fuel required. For military applications, each of these factors must be taken into account to find fuel cells suitable for certain applications. Types of fuel cells include proton exchange membrane, direct methanol, alkaline, molten carbonate, phosphoric acid, and solid oxide.

Fuel cells work by producing an electrical current. To understand the basics of fuel cell operation, consider a fuel cell that works with hydrogen as a fuel. In the illustration above, hydrogen atoms are directed toward an anode that splits the atoms into protons and electrons. The protons enter the fuel cell at the anode while the electrons are directed through a circuit. The protons travel through the electrolyte to the cathode. At the same time, oxygen enters the fuel cell at the cathode, where it combines with the electrons and protons to form water. Note that the electrolyte plays a crucial role: It allows the passage of protons to prevent adverse chemical reactions from taking place in the cathode. Heat and water are byproducts of this reaction and can be captured for other purposes. This type of fuel cell will generate electricity as long as it is supplied with hydrogen and oxygen.

With such ease of operation, one might ask, “Why can’t I just go out and buy a fuel cell?” Fuel cells are starting to appear on the commercial market, but a number of challenges inhibit widespread availability. Cost and durability are two major challenges. Others include size, weight, and thermal and water management. Fueling hydrogen fuel cells, in particular, is a challenge because production, transportation, distribution, and storage of hydrogen are difficult, especially on the battlefield. Producing hydrogen using a reformer is also technically challenging. A hydrogen reformer is a device that extracts hydrogen from other fuels, typically methanol or gasoline.) Aside from these technical issues, the infrastructure is not available to support large-scale conversion of military systems to operate on alternative energy sources such as fuel cells.

Over the next few decades, however, fuel cell size and cost will decrease. Reformer technologies will improve to the point that the generation and storage of energy in the form of a fuel—most commonly hydrogen—will become realities. Moreover, this fuel can be renewably derived from water and clean energy. The coming “hydrogen economy” will enable energy systems that are safer, cleaner, and more versatile than the systems in use today. In the future, fuel cells will power numerous electronic devices. Fuel cells also will play a critical role in helping to displace fossil fuels as the primary source of our future military energy infrastructure.

Fuel cells are an extremely attractive source of energy for tomorrow’s battlefield. They will provide the warfighter with increased mobility, and they will enable information systems to function reliably and efficiently during lengthy battlefield missions. Because of its compactness, the proton exchange membrane fuel cell, in particular, will be a prime candidate for vehicles and other mobile applications.

Biomass energy. Biomass refers to any plant-derived organic matter available on a renewable basis, including dedicated energy crops (such as corn), trees, feed crops, agricultural crop wastes and residues, aquatic plants, animal waste, and municipal waste. Biomass energy technologies seek to use these renewable biomass resources to produce an array of energy-related products, including electricity; liquid, solid, and gaseous fuels; and heat and chemicals. Biomass energy (bioenergy) has tremendous potential for development, in part because biomass stores its energy until it is extracted. As a result, biomass offers tremendous opportunities for creating sustainable resources that provide energy sources to the future battlefield.

Bioenergy is not really new; energy from plants and plant-derived materials has been used for centuries. Wood, for example, is still the largest bioenergy resource available today. Currently, there are four classes of bioenergy systems: direct-fired, co-fired, gasification, and modular. Most systems are direct-fired; biomass fuel is burned in a boiler to produce high-pressure steam that causes a turbine to rotate, thereby producing electricity. Co-fired systems involve substituting biomass for a portion of the coal used in an existing power plant furnace. Gasification systems operate by heating biomass in an environment in which solid biomass breaks down to form a flammable gas. A modular system is perhaps the most important bioenergy system to EoD. Modular systems employ some of the same technologies mentioned above, but on a much smaller scale. This could permit sustainment of units deployed in remote areas where biomass is readily available but electricity is scarce.

Other forms of energy. In addition to the expanded use of fuel cells and biomass on the future battlefield, other forms of energy generation and storage are viable and will become more readily available. Renewable energy generated from sources such as wind, light, sound, and water is sure to appear on future battlefields. The emergence of Future Combat Systems and associated unattended ground sensors will require alternative forms of energy to alleviate and potentially eliminate the need for an infrastructure (batteries) to supply energy to these sensors. Units engaged in stationary field operations also will be able to generate energy from nonorganic waste, such as plastic packaging. This would decrease the personnel, fuel, and critical transport equipment needed to remove and dispose of such waste.

Harnessing the energy content of waste generated during military field operations would reduce military logistics requirements in two ways: It would provide fuel for on-site energy generation, and it would dispose of waste that otherwise might have to be transported from the battlefield. This form of energy generation and storage could replace much of the fuel needs for electrical power generation in the field, thereby saving the military services millions of gallons of costly diesel fuel. It also could significantly reduce the logistics resources required to deliver fuel to deployed forces.

Energy Distribution: Smart Grids and Microgrids

It takes energy to move energy. Energy generated at certain locations (often remote) must be distributed for use. Pipelines, ships, trains, and trucks carry fossil fuels from point to point, while power lines carry electricity from point to point. Significant energy is expended transporting fuels, and current power grids suffer from electrical resistance and load unpredictability.

To be more efficient, energy distribution networks must have new materials and advanced logistics systems. Large-scale use of distributed and intermittent renewable resources, such as solar energy and wind, requires intelligent, networked grids to deliver power efficiently over long distances. Lengthy and vulnerable supply lines fuel large diesel generators that supply energy to myriad devices that support military operations. Current energy distribution systems cannot adapt to changing energy demands and generally are inefficient as a means of transporting or transmitting energy. Energy transport and transmission and distribution systems must be safe, secure, reliable, sustainable, and cost effective. Smart grids and microgrids offer the potential to meet all of these criteria for the future Army.

Smart grids. Smart grids promise intelligent, efficient energy distribution because they will be able to adapt to ever-changing energy demands. Truly intelligent electrical grids should be able to accept and feed electricity to remote sites. As energy demands increase on the future battlefield, the Army will need distributed storage and generation smart grids that can detect usage levels and immediately adjust their operation for greatest benefit. Intelligent distributed energy generation is certainly within the realm of the possible, but it will require some advanced technologies.

Smart grids must have the ability to deal with intermittent renewable energy sources such as remote solar and wind farms and, at the same time, accept energy from constant sources such as fuel cells. Smart grids will be adaptable and have the ability to support computer software upgrades, along with new hardware such as superconducting fault current limiters, transformers and storage devices, digital power controllers, and next-generation nanotechnology transmission lines. Smart grid management will use digital control, automated analysis of problems, and automatic switching capabilities such as those currently employed by the Internet. Advanced
routers that can break energy into packets for distribution over various routes to relieve congestion (comparable to those used in computer networks) also will be necessary.

Smart grids will be interconnected to a web of other infrastructure grids, including water, gas, telecommunications, transportation, automation, and fuel systems. As part of an integrated infrastructure, smart grids will require computer simulators and threat simulators to monitor complete grid activity. Inexpensive electronic devices will be attached to most elements of a smart grid. These devices will have memory and processing capabilities that can identify parts. Their location will be detectable by a global positioning system, and they will communicate wirelessly with central command and control centers. Real-time sensing and control of future grids is needed for complete end-to-end generation, storage, and distribution of energy.

High-temperature superconductivity and nanoscale technologies are expected to deliver several breakthroughs that could revolutionize smart grids. “Quantum wire,” which is woven rope made from carbon nanotubes, could have electrical conductivity that is higher than that of copper at one-sixth the weight and twice the strength of steel. (See “Designer Materials” in the November–December issue of Army Logistician.) A grid made up of quantum wires would have no line losses, thus alleviating the need for certain emergency energy-generation capabilities.

Microgrids. Unlike smart grids, microgrids are smaller “community” networks of diverse energy-generation sources, such as solar energy, wind, and fuel, which have the potential to transform the “electricity network” in the same way that the Internet changed “distributed communication.” More specifically, microgrids consist of small collections of power-generating technologies that are suitable for a collection of users who are in close proximity to the generation source. These types of grids have EoD capabilities that make them particularly useful to an adaptable force.

Microgrids are often compared to peer-to-peer file-sharing technologies, in which demand is split up and shared around a network of “users.” They could exist as stand-alone power networks within small communities, or they could be connected to larger power-generating communities. For example, they could be plugged into a smart grid.

Microgrids can provide safe and secure energy distribution for military operations because of the many energy-generation types that are incorporated into their distribution process. They are reliable because of their small network size and redundancy of generation and storage. They are sustainable because they use renewable energy technologies, and they are cost-effective because they use renewable energy sources. For military applications, microgrids are particularly attractive because they can deal more efficiently with fluctuating power demands.

The Deep Future

How can the envisioned EoD condition be achieved? In the far term, energy generation, storage, and distribution to the point of effect when needed could be achieved with a space-based satellite system. Energy generation could take place in space, on earth, or in the atmosphere from multiple sources. A space-based satellite system would allow energy to be distributed to warfighters regardless of their location or energy requirements. Because energy distribution will be space-based, energy generation sources (nodes) could be fixed, mobile, space based, or earth based.

The ultimate goal of EoD is the ability to distribute energy from any one of the many energy generation or storage nodes to any location, in sufficient quantity, on demand. Achieving that goal would mean near or complete elimination of fossil fuels and perhaps the entire current energy distribution infrastructure.

Logistics Benefits


The benefit of EoD to Army logistics is significant both on and off the battlefield. At the theater level, future energy sources will reduce the need for hydrocarbon-powered systems. This capability will enable the combatant commander to meet mission requirements with fewer support organizations in theater, thereby reducing the logistics footprint and increasing Army and joint force deployability and sustainability. The use of multiple energy sources will give the commander several options for energy generation and use (local sources or organically generated) and will increase operational readiness while reducing force vulnerabilities. Army installations will be able to minimize costs by generating energy using organic waste and other feedstock. This will allow for decreases in energy requirements, thereby allowing maximum use of all available assets to support the mission.

Distribution and delivery of energy will be affected significantly as well. Future advances in materials technology will enable more efficient storage and use of energy that may improve support unit deployability and battlefield distribution. These increased energy capabilities will relieve future combatant commanders of the tremendous burden inherent in distributing fuel in the battlespace. They will have more time to focus on other complex operational and logistics issues. From simplifying force-reception challenges to reducing vulnerabilities in sustaining stability operations, EoD promises to increase operational flexibility and strategic readiness significantly.

Some portions of EoD are achievable by 2030. A major breakthrough, particularly in fuel cell technology, is probable before 2030. Technology advances in photovoltaics (solar power technology), bio feedstock conversion, fuel cells, capacitors, remote refueling systems, satellite-based power units, fuel reformers, and energy storage are critical path drivers to EoD’s ultimate feasibility and success. Some advances or breakthroughs will probably be available for “spiraling out” to the Army or joint force before complete EoD is accomplished. Depending on the technology adopted, radical changes to tactical and operational logistics capabilities may occur, which will trigger new and significant DOTMLPF implications.

Research is underway in all energy-related areas as the Nation seeks to eliminate its dependence on foreign oil. Several technical advances have occurred in the use of organic feedstock to produce electricity. Commercial large-scale waste-to-energy converters have been marketed, and it may be possible to reduce them in size so they can be used on the battlefield. Photovoltaics is a heavily commercialized area that enjoys significant developmental funding outside of the Department of Defense. Advances in solar power are occurring with breakthroughs in more efficient materials and designs. Multijunction, thin-film nanoscale solar cells are in development, promising up to 50-percent energy conversion. Recently, a major scientific breakthrough occurred in the stabilization and storage of anti-matter, a first step toward unlocking the door to the most powerful energy source currently known to man. In the coming age of directed-energy weapons, the implications for rearming and refueling are enormous.

Logisticians must demonstrate a willingness to investigate innovative concepts and technologies leading to onsite usable energy and power systems at the point of effect in the battlespace. We should develop a basic understanding of the scientific and technological underpinnings of these capabilities in order to influence policies and procedures that deal with the generation, storage, distribution, utilization, and standardization of new energy technologies.
ALOG

Dr. Keith Aliberti is a research physicist in the Sensors and Electron Devices Directorate at the Army Research Laboratory at Adelphi, Maryland. He currently serves as the laboratory’s liaison officer to the Army Logistics Innovation Agency at Fort Belvoir, Virginia. He has a B.S. degree in physics from Rensselaer Polytechnic Institute and M.S. and Ph.D. degrees from the State University of New York at Albany.

Thomas L. Bruen is a logistics management specialist at the Army Logistics Innovation Agency at Fort Belvoir, Virginia. He has a bachelor’s degree in engineering from the U.S. Military Academy and is a graduate of the Army Management Staff College’s Sustaining Base Leadership Management Program.