Army (Acquisition, Logistics, and Technology) to accomplish the following tasks:
Expand upon the conclusions from the ARL/CECOM Energy and Power Workshop for the Soldier, held on 15-17 October 2002, through the specification of both impact and feasibility of incorporating power management components, techniques and procedures for powering low-power electronic devices. The specific regimes from the workshop were: 20-watt average with 50-watt peak and 100-watt average with a 200-watt peak for up to 72-hr missions. Address power for high-power draw applications such as exoskeleton applications (1 to 5 kW average).
Assess electric power technologies to support soldier applications associated with future power and energy demands on the battlefield, e.g. expected OFW operational capabilities for the 2005-2025 time frame, with emphasis on alternative compact high-power and energy-dense sources, power management and distribution techniques, and low-power electronics such as asynchronous microchips, smart dust, etc. Assess technical risks and feasibility associated with each of the technologies and make recommendations pertaining to their potential efficacy and utility within the context of future OFW operational capabilities. Consider risks associated with technology development, integration of hybrid generators and sources, adaptation of commercial technologies, and battlefield logistics. Systems concepts involving appropriate power sources, power management and low-power electronics are to be specified and delineated.
Update the technologies evaluated in the 1997 NRC report on Energy-Efficient Technologies for the Dismounted Soldier including changes in individual technology development trends. Determine advantages and disadvantages for appropriate technologies in prospective application areas. Develop standard measures to facilitate comparison.
Prepare a consensus report documenting the study results and containing findings and recommendations to assist the Army in its development program. Prioritize the energy source alternatives appropriate to each application. Propose science and technology (S&T) objectives leading to the future incorporation in the Objective Force Warrior program. The report will include:
Recommendations for examined technologies with high benefit for target regimes with detailed justification for technology selection or rejection.
Recommendations for power distribution techniques for soldier systems. Applicability of low-power electronics, such as asynchronous microchips, smart dust, etc., to soldier device loads.
Recommendations for centralized vs. distributed power management for soldier systems including software/hardware techniques for control and conversion.
Applicability of examined technologies to single type sources vs. hybrid sources considering logistics, versatility, utility, environmental factors, safety, reliability, logistic infrastructure, manufacturability and availability.
Recommendation for recharging from soldier carried sources, robots (or vehicle) or fixed platforms.
Recommendations for predictive models and modeling techniques that would elucidate power use and management.
This executive summary summarizes key findings, including the science and technology (S&T) objectives in compact high-power and energy-dense source technologies for each of the regimes, and enumerates the specific recommendations contained in the study report.
Consistent with the ARL/CECOM Workshop, the committee assumed that the 20-W regime included power solutions for computers, radios, sensors, displays—all electronics subsystems of the LW ensemble. The 100-W regime included niche applications such as high-demand laser target designators and future microclimate cooling capabilities. Finally, the 1- to 5-kW regime was assumed to include the most power-intensive capabilities, such as portable power generators, rechargers for rechargeable batteries, and future exoskeleton devices.
The committee assessed and compared technologies at varying levels of technology readiness. Energy per unit of system mass, i.e., specific energy, served as the primary metric for selecting the technologies with greatest potential for Army purposes from among the many alternatives. Three important issues had to be addressed to make valid comparisons. First, the total energy produced must be measured under identical load conditions (power profile). Second, since fully packaged systems are not available for many of the emerging technologies, comparable parameters had to be estimated. Third, since batteries specify different performance specifications for different cell sizes, the committee provided varying allowances for packaging.
Fueled systems, which are in various stages of development, can be used to replace batteries as well as to supplement batteries in a hybrid system; the committee calculated standard mission energy requirements and used these to compare required masses for battery and fueled systems. Such things as fuel tank and fuel, energy content of the fuel, and energy conversion efficiency were used to compute comparable performance metrics.
Based on these considerations, the committee evaluated