Many of my colleagues love to leave their computers on when they go home for the night. Our IT department has been discussing a software solution to this for the last 6 months with no obvious sign of progress.

In our unit we have taken advantage of having an excellent IT administrator who has written a script  to all the PCs in the renal unit that shuts them down at a specified time. We have gone for 2200 in the first instance and have only excluded two PCs in the ward area. We estimate that at least 7 PCs were being left on overnight which didn’t need to be. By switching off at 2200 we will be saving 10 hours of electricity per PC per day i.e. 70 hours. 

Our difficulty lies in quantifying how much electricity this saves as some of time the PCs would be in standby and not consuming as much as when fully switched on. The way our electricity circuits are in the unit we cannot apply and OWL-type device to quantify it.

Has anyone else tried this in their place of work and has anyone come up with a realistic algorithm for calculating potential savings?