Background: Cloud computing data centres, due to their housing of powerful ICT equipment, are high energy consumers and therefore accountable for large quantities of emissions. Therefore, energy saving strategies applicable to such data centres are a very promising research direction both from the economical and environmental stand point. Results: In this paper, we study the case of private cloud computing environments from the perspective of energy saving incentives. However, the proposed approach can also be applied to any computing style: cloud (both public and private), traditional and supercomputing. To this end, we provide a generic conceptual description for ICT resources of a data centre and identify their corresponding energy-related attributes. Furthermore, we give power consumption prediction models for servers, storage devices and network equipment. We show that by applying appropriate energy optimisation policies guided through accurate power consumption prediction models, it is possible to save about 20% of energy consumption when typical single-site private cloud data centres are considered. Conclusion: Minimising the data centre's energy consumption, on one hand acknowledges the potential of ICT for saving energy across many segments of the economy, on the other hand helps ICT sector to show the way for the rest of the economy by reducing its own carbon footprint. In this paper, we show that it is possible to save energy by studying the case of a single-site private cloud data centres. We believe that through the federation of several cloud data centres (both private and public), it is possible to minimise both the energy consumption as well as CO2 emissions. © 2012 Basmadjian et al.