Morphologic analysis has been used to study the possible weight benefit and secondary effects of replacing multiple reserve batteries by new energy systems in the Swedish soldier system. Three alternative systems have been studied and compared: The SWIPESTM (developed by Arotech Corp.) and the IPS (developed by BAE Systems Ltd.) are rechargeable battery solutions and the JENNY 600S (SFC Energy AG) is a methanol fuel cell. Six personnel roles were equipped with electronic devices in different configurations, including planned but not yet fielded acquisitions (computer and personal display). The mission length was varied from 8-72 hours. For shorter missions (<24 h) there was no weight advantage in introducing the new energy solutions. For >24 hour missions there is a weight advantage by using the SWIPESTM in the most energy demanding roles. For >72 hour missions there is a weight advantage by using the JENNY 600S. Both SWIPESTM and IPS are capable of prolonging missions when reserve batteries are not available. However, many assumptions have been made regarding battery efficiency, since this will vary greatly depending on factors such as battery age, history and operating temperature. In addition the SWIPESTM is a more developed system than the IPS, which is a prototype. The analytical model used is generally applicable to studying modifications in the soldier system and potential effects on overall performance. This study has briefly considered effects on comfort, mobility, protection (ballistic & signature aspects) and weapon handling.