Calculating Power Consumption

Hi All;

I hope this is in the right spot. I've come across an interesting conundrum at work. My boss wants to propose that we save money by virtualizing our data center with VMWare, the backing for this being the saving of power and cooling. The problem with this is that in his proposal he needs some hard numbers on power consumption. As with most data centers we have ridiculous server sprawl. Anyone know of any way for a script to probe machines for its specs and get the power supply rating? Or am I on my own for that? And last but not least. Once I have all the power supply ratings and usage percentages, how is the best way to calculate how much power that system is drawing on average? Thanks in advance.

This might be of help.