No. A UPS with Parachute software will let you know how much you're drawing from the wall, or a Killawatt meter will do basically the same.
1150w is much more than enough, unless you're running a couple dozen drives and off the wall cooling.
I don't really use a Dell anymore ( My old Inspiron 9100 laptop sometimes )
Thanx to the help I found here I built my own a couple of years ago and the photo is what it evolved into.
The photo is a little dated at this point, has the Dominators on it, they've been replaced with the GSkill in my sig ( A reccomendation from The_Blood_Raven ).