Energy consumption is a concern with today’s mobile devices. While the capabilities of the devices have improved rapidly over the last ten years transforming also the way these devices are being utilized, battery technology has not been able to keep up with this evolution. As a consequence, there is an increasing gap between the battery capacity and the amount of energy required for typical usage. The situation calls for solutions that enable more energy efficient usage of mobile services. eMo-project addresses this problem by building theoretical models of energy consumption in mobile devices with the help of experimentation and measurements. Based on the models, we develop new protocols that aim for energy-optimal execution. We take a holistic approach and aim for an integral solution that incorporates these protocols into an intelligent and autonomic framework. This target solution consumes radically less energy than currently used solutions.