Green Computing

From Windows Vista Blog (Dec. 2006):

A typical Pentium 4 PC with a 17" LCD monitor draws about 102.6 watts of power (think about a 100 watt light bulb). That same PC and display in a sleep state draws only 5.6 watts, or 97 fewer watts.

If you figure that a PC is used for active work for 10 hours a day, 5 days a week, 52 weeks per year, that is 2,600 operating hours. With 8,760 hours in a year (365*24), there are actually 6,160 potential idle hours per year. Since sleep mode uses 97 fewer watts than full power mode, the total savings is 597 kWh per year -- and by the way, the impact is obviously even greater (760 kWh) if you use a CRT monitor since they draw more power than LCDs.

The paper uses an estimate of $0.0931 per kWh from the US Department of Energy, so for a home user with one PC, the savings amounts to $55.63/year (more if the PC is used less than 10 hours a day).

While that is great saving for a home user, think about an enterprise with 10,000 desktops where the potential cost savings would be $556,300/year -- and we haven’t even tried to estimate the HVAC savings. With IT budgets becoming sequentially tighter year over year, it's nice to be able to have this kind of impact. I would be remiss if I didn’t mention the fact that there is also a significant environmental impact as well.

The EPA estimates that every kWh of electricity generates 1.55 pounds carbon dioxide (CO2) emissions so each PC that moves to Windows Vista generates 926 fewer pounds of carbon dioxide or about 8% of what the EPA estimates that a typical car generates in the course of a year-- so for every 12 and a half PCs that are running with Windows Vista’s new power management capabilities, it’s like having one less car on the road.