The Lights Are on but Nobody’s Home

You are, again, the last one to leave the office. You turn the lights out as you make your way towards the door. And you notice something that you have seen a thousand times before but never thought about: all the computers in your office are still on. Or, as the title of this entry suggests, the lights are on but nobody's home.

What are all those computers doing at night? In some cases, they are downloading software or security updates. Most of the time, however, they do nothing. More accurately, they burn electricity but produce no useful work. Each is like a tiny furnace, burning chunks of fossil fuel, doing nothing but – at the same time – not doing anything good. What can be done?

Isn't Electricity Clean?

But wait – electricity is a clean source of power. You don't need to worry, right? Actually, each kilowatt of electricity creates 1.33 pounds of CO2. That is the average for the United States, and is based on the fact that 50% of electricity in the United States is generated by burning coal. It is the cheapest form of fuel, which is why it is so attractive to power companies. From an environmental point of view, coal is the dirtiest and so – in environmental terms, at least – is more expensive in terms of its contribution to Global Warming. Is there a good alternative around? Yes, natural gas. Details of that will have to wait for another time.

Controlling PC Power

Computer power management – also sometimes known as "PC power management" – involves taking steps to reducing the power wasted when computers are sitting idle. At home, the best thing you can do is to turn off the computer when you are not using it. Many people already do this at home, but more people need to get on the bandwagon.

In the office – especially in larger companies – computers are generally left on all night. Why? The stated reason is that IT departments need to update software at night. And yet, the actual time needed for this activity is generally very small (a few hours per month, perhaps). During the rest of the time these systems burn electricity, grind down their parts (especially the motors, which typically turn at 5,000 - 10,000 RPM) while doing no useful work. Quite a bit of money could be saved by turning off these workstations at night and over weekends. How much?

How Much Can Be Saved?

For an example, let's go to Hawaii. It has the highest electricity rates, and so can be used to best illustrate the possible savings. If you worked in Hawaii (I am told that there are people who work there) in a firm with 100 desktop workstations and each workstation used 135 watts of power (an average amount for typical systems), the cost of electricity for each year would be about $26,000. Turning those workstations off on evenings and weekends would save your firm about $20,000 per year. That is a 76% reduction. Run the calculations for yourself by clicking on this link: http://www.enovativenergy.com/Cpm_Calculator.aspx?Systems=100&Watts=135&Rate=22.20

As attractive as Hawaii might be as a vacation destination, it does have the highest utility rates. What kind of savings would be possible for a similar firm in another location – say in Chicago? At 11.42 cents per kilowatt hour, the rates are half of those found in Hawaii. They are also closer to the average for the whole USA. The cost of running the same PCs as in the previous example (100 systems with each using 135 watts of power) is around $13,500. Turn them off on evenings and weekends, however, and those same workstations only cost $3,200 – a net savings of $10,300. Run the calculation yourself by clicking on this link: http://www.enovativenergy.com/Cpm_Calculator.aspx?Systems=100&Watts=135&Rate=11.42.

Automating PC Power Management

When there are many systems that need to be controlled, it helps to have power management software to help automate the process. This allows centralized control over many computer systems, and is surprisingly affordable. In fact, in many cases the electrical utilities will subsidize the cost of purchasing such software. For details on computer power management, check out this page on the Enovative Energy website: http://www.enovativenergy.com/cpm.aspx.