The usage data is daily uploaded by each computer (or VM) in the organisation, to a central store. The manager can review these usage and data via management reports. Using this data, he/she can take action to optimize energy usage. New about this concept is the effort to get workers in an organisation to know about energy usage of their software and computers. Although Microsoft Windows as well as other operating systems long have the possibility to reduce the energyusage of a computer, there has never been a clear connection between the power plan and energy savings. ESSaver does exactly that!