With those PC running days and nights in enterprise world, heavy energy usage are consumed and some research efforts have been spent to reduce and optimize its usage. Just recently, a group of computer researchers from University of California has developed a new software named as SleepServer that is aimed to tackle this problem.
As different from other existing technology that would wake the PC based on connected network, SleepServer uses a slightly different approach by creating tiny virtual images that will respond to applications or network events while the PCs are kept in low power sleep mode. Even though the PCs are in sleep mode, they can still be accessible using VOIP (Voice Over IP), Instant Messaging or other means of peer-to-peer network communication with easy compatibility with existing applications such as VNC, Remote Desktop or SSH. And as and when the virtual image is not able to handle certain request (which is also user-configurable), it will wake up the physical PC from sleep mode for necessary services and actions. Based on data collection, the energy saving estimated for 30 running PCs is around 60 percent (or equivalent to $60 cost saving per PC for one year), as compared to when they are left running for 24/7.
Since it is software based, the solution is highly scalable and can be enabled almost immediately within enterprises without complicated or costly hardware modules. No actual commercial availability yet, there is a plan to deploy the SleepServer technology over 1000 PCs across whole campus in short future.