Abstract: In this position paper, we argue that, with an appropriate operating system structure, energy in mobile computers can be treated and managed as just another resource. In particular, we investigate how energy management could be added to the Nemesis OS which provides detailed and accurate resource accounting capabilities in order to provide Quality of Service (QoS) guarantees for all resources to applications. We argue that, with such an operating system, accounting of energy to individual processes can be achieved. Furthermore, we investigate how an economic model, proposed for congestion avoidance in computer network, and recently applied to CPU resource management, can be used as a dynamic, decentralised energy management system, forming a collaborative environment between operating system and applications.