Last year Microsoft released a SCOM Management Pack for monitoring and managing the power consumption of Windows 2008R2 servers. This management pack gives you some insight into the power consumption of the servers and, even more interesting, gives you the ability to control the power savings and therefore reducing the total consumption of a server. And keep in mind that every Watt you can save with your servers is another Watt saved in you cooling.
One of the interesting features of windows 2008R2 that will reduce your power consumption is the use of Core Parking. Modern servers are using multiple multicore processors, giving you a lot of horsepower. But this horsepower is not always needed. When the system is not using all of the cores Windows 2008R2 actually put these unused cores in a park mode. If necessary, Windows will wake these cores when needed. This feature, combined with reducing the speed of the processors can significantly lower the power consumption.
If you want to see the 2008R2 Core Parking in action, you can use the performance monitor of Windows 2008R2, this will give information about the usage of the different cores.
So, Microsoft is getting serious with their power savings tooling. After the announcement of SCCM 2007R3, which is very useful to reduce the power consumption of your workstations, the use of the power management pack for SCOM can really save a lot of energy, and thus a lot of money.