The paper first outlines the challenges the global energy system is facing. It then summarises the present knowledge of energy efficient solutions in all energy using sectors from primary energy to useful energy and, more importantly, from useful energy to energy services (material efficiency...

Although information and communication technologies (ICT) consume energy themselves, they are considered to have the potential to reduce overall energy intensity within economic sectors. While previous empirical evidence is based on aggregated data, this is the first large-scale empirical study...