General document | Land 125 – Power Technologies Review

Abstract

This review provides an overview of the technologies and issues relevant to future dismounted soldier power systems. The issues with current systems are identified, namely weight, volume, cost and logistics, and power source technologies to address these issues are discussed.

Executive Summary

The evolution of capability requirements for dismounted soldiers prescribes greater use of electronic equipment by soldiers in the battlefield. This is increasing the amount of power and energy required by soldiers. Primary batteries, and to a lesser extent secondary batteries, are the predominant technologies used by soldiers to power their electronic devices. However, primary batteries cannot be recharged. This results in a large weight burden for soldiers, who must carry many battery spares, and demanding logistics requirements to regularly replace batteries. Without reducing the power and energy required by soldiers, these issues are likely to be exacerbated in the future. Therefore, alternative technologies are being developed and effort is being applied to reduce soldier power consumption.

The information presented in this document was gathered from a range of resources discussing issues and technologies relevant to dismounted soldier power provision. These resources included conference presentations, journal articles, reports and relevant expertise within the Defence Science and Technology Organisation (DSTO). This information was used to identify the key extant issues with soldier power provision and technologies that may address these issues.

The main purpose of this document is to discuss alternative solutions for providing electrical power to dismounted soldiers. The discussion aims to highlight the benefits of each solution and known issues that may arise as a result of their use, as well as identifying aspects known to require further development. A number of power source technologies are discussed, including advanced primary and secondary batteries, supercapacitors, fuel cells, energy harvesting devices and microengines. Technological maturity, system weight and associated logistical requirements are key factors that affect the suitability of these technologies for soldier power provision, although other aspects, such as safety and cost are considered.

The development of improved primary batteries may reduce associated weight and logistics issues by increasing the energy available from individual cells. Secondary batteries are attractive replacement for primary batteries because they may reduce resource and logistics costs. Further implementation of secondary batteries is likely to depend on the development of battery charging capabilities. Without lightweight battery chargers, soldier load on extended missions may increase if heavy battery chargers need to be carried. Fuel cells could offer large energy improvements for longer missions, but significant additional logistics infrastructure may be required if non-standard military fuels are used. Similar energy improvements may be achieved with microengines, but they require a number of technical issues to be addressed. Energy harvesting devices provide an opportunity to reduce the amount of energy carried by soldiers and the associated logistics burden. However, their implementation is likely to depend on improvements in conversion efficiencies and effective integration with the soldier power system to prevent soldiers from being overburdened.

The integration of soldier power systems is an important consideration to optimise soldier energy usage. These systems connect all electrical loads to one or more central power sources. Although integrated systems have added overhead for the distribution and conversion of power, they facilitate system-level power management. This allows smarter use of energy through the utilisation of energy conservation strategies with the potential for weight savings if energy saved through power management can offset the overhead of the integrated system. Where high power requirements exist for soldiers and single source solutions are insufficient, hybrid power systems should be considered to provide both high power and energy. Ideal soldier power solutions will reduce the weight and logistics burdens of soldier power provision, but they must be adaptable to the battlefield environment.