Currently there is a high awareness for energy consumption due to global energy production limits and environmental concerns. As the energy fraction currently consumed by ICT related equipment is substantial (about 8% of electricity production worldwide in the use phase) and the growth rate in this particular sector is spectacular, also in the ICT sector adequate solutions are needed to allow sustainable growth. In this paper an analytical modal for the power consumption of thin clients is presented. It is compared to the power consumption of a desktop PC in order to estimate the power efficiency gain that can be achieved by implementing the thin client paradigm. The paper concludes with an experimental study on currently available equipment, to translate the generic conclusions into their current implications and trade-offs.