During the Windows Vista session at today's TechNet event in Jacksonville, FL, I talked about some of the new group policies that come with Windows Vista and Windows Server 2008. I had a slide that mentioned a study indicating up to $50 per PC could be saved annually by utilizing power management. The new group policy options for power management provide a way of centrally configuring and enforcing the power settings on Windows Vista machines. I was asked to post the study this information came from, so here you are:
Join the ENERGY STAR Low Carbon IT Campaign is the study that talks about the savings that can be made by using power management options.
At the same website I also found this article, Activating power management features in enterprises, which also includes an online savings calculator to help you estimate your savings.
UPDATED INFO - Aug 22nd 2008
I found this today with some more documents that will be of interest with regard to Windows Server 2008 Power Savings.
Documents you can download are: