Green IT is one of the most recent buzzwords in the IT business. Often it is considered as the key to all future IT problems by one half of IT experts and as an overestimated hype by the other half. Green IT aims to integrate information and communication technologies into a business wide sustainability strategy without any productivity drawbacks. It includes measures and tactics to reduce the IT's environmental impact e.g. by reducing the power consumption and using energy from renewable sources, and by using technologies such as virtualisation. Green IT is considered as the key to all...