Well it's rather pointless for me since I take part in distributed computing, so the only thing that'll be turning off is my monitor (which already did in the first place).
EDIT: It is badly incorrect with the graphics card usage. It says my 7800 GTX uses 20 watts - if it did, it wouldn't need the extra PCI-E power (the PCI-E port provides up to 60W, a 7800 GTX underload uses 100W)