Should My Computer Run All The Time?

I am often asked whether I recommend leaving a computer on all the time or turning it off. The computers in your office are low hanging fruit when it comes to saving energy, whether you’re in it for the monetary benefits or just because you’re trying to be kinder to the environment. Some are surprised to hear me recommend shutting down all workstations at the end of the workday.

I recently hooked a Kill-A-Watt (Amazon Affiliate Link) meter up to a modest computer typical of what I might find at my clients’ offices and found that it uses 1.7kW in an eight hour workday. This was at an idle – I did no work on it at all on it. So here is a little math on the cost of leaving the system on outside of working hours:

Assuming 10 cents per kWh we burned 17 cents worth of electricity. (Roanoke area residential cost in January 2011)
If I leave it on all night (5pm-8am) we burn an extra 32 cents outside of “working hours.”
For 20 work days we have $6.40 of excess cost.
For 8 weekend days we have $3.92 of excess cost.
That gives us $10.32 every 28 day period, of which we have 13 in a year, for a total of $134.16 per year in excess costs.

So on this computer’s fourth birthday, it will have used $536.64 if I had a habit of leaving it on all night. As a small business owner, will that $134/yr for each computer help your budget?

Let’s turn them off!