Cut Costs, Conserve Energy with PC Power Management

Most system builders are aware that many households are now moving to multiple PCs, and with the growing number of "always on" servers and media boxes, consumers (and the system builders themselves) have more to gain by working to conserve energy. Not to mention, we're all concerned with trimming utility bills and making ecologically sound decisions when it comes to PC purchases.

This recipe as all about power for PCs: What it costs, how to conserve it and where to look for savings. Read on and I'll show you what I've learned about measuring and calculating energy costs and share some energy-saving tips with you. The recipe will help you trim your own utility bill and save your clients money—and you'll also be doing the "green" thing for the environment as well.

REAL-WORLD ENERGY COSTS

These days, most businesses are taking a hard look at their utility costs, and easily-accomplished first step in enhancing the bottom line. For example, many SMBs are finding dramatic savings when PCs are simply turned off when not in use.

In 2006, the City University of New York began outfitting its fleet of PCs with a program called Surveyor 4.0, which acts like a night watchman to automatically turn computers off when they are idling in the dark. Deploying this software enabled more than 10 percent in savings from the university's computer power bills (or about $320,000 a year, say the university officials). Further, the Wall Street Journal recently reported that a commercial printer in Wisconsin with a similar strategy—is currently saving 35 to 50 percent, or as much as $70,000 annually.

Right now, you're probably thinking: "Hey, that's fine if you have 20,000 PCs, but what about my clients who have only 10? What can they save?" Well, depending on your PC, Verdiem Software reports that their Surveyor software can save as much as $40 per PC annually simply by powering down at night. When you consider that you're not giving up any functionality—$400 a year looks pretty good. And automatically turning off a PC is easy!

To understand the impact of this and other energy saving measures, it helps to understand how energy is measured and how much you're paying for the energy to keep your PC on.

THE COSTS OF ELECTRICITY

Measuring the costs of electricity depends on where you live, how much you use, and when you use it. There are also fixed charges that you pay every month no matter how much electricity you use. The best source for this information is generally found on your utility bill. In most cases, the bill itself will tell you the rate in your area—but if it's not on your bill then look it up on the utility's website. What you're looking for is your cost of electricity per kilowatt-hours (kWh). Your bill might have multiple charges per kWh (e.g., one for the "base rate", another for "fuel"). If so, you'll have to add them up to get the total cost per kWh.

If all else fails, look at the Energy Information Administration site for an estimate. In many cases, this is easier than trying to figure out the confusing utility bill. And it's actually interesting to see what everyone else in the country is paying. If you happen to live in Connecticut or California however—it might be pretty depressing—as you'll see you're being charged some of the highest rates in the U.S.

In March 2006, the U.S. Department of Energy reported average cost of residential electricity in the U.S. was 9.86 cents per kWh. But the cost of electricity varies by region of course, and it's subsidized in some states and at a premium in others. For our discussion about energy measuring and savings, you'll want to consider you local cost for it. In the U.S., costs range from a low of 6.15 cents per kWh (Oklahoma) to a high as 21.94 cents per kWh (Hawaii).

Once you know what your electric power costs, you may find that you have a whole new outlook on conserving it. So, let's take a look at how to measure and calculate energy costs.

CALCULATING ENERGY COSTS

Maybe you haven't thought much about power recently. You see the EnergyStar logo and you set up your machines to hibernate—but have you ever wondered about the actual cost of running one of those PCs? Do you know what it's costing you to leave a computer on 24 hours a day, seven days a week? How much you can save by shutting down? How much more power does a high-end video card pull? You say you don't know? Well, here's how you can figure it out.

The first thing you need to know is how much power your computer draws. You can continue to guess, as most of us have done, adding up the power ratings of the components for a ballpark figure, but the best way is to measure the actual power consumption. You'll find it much more accurate than your estimates. When you see the results, you'll have a new appreciation for power supplies and other component pieces.

Now, to do this accurately, you'll won't need much more than a $30 device like the Kill A Watt. This nifty little device sits between the power source (i.e. a wall receptacle) and whatever load you're measuring. Once you've measured the power draw in watts you'll need to convert that to kilowatt-hours. Here's a look at P3 International's Kill A Watt:

Using this tool here's the method I used to calculate the annual cost of running my own server, which draws approximately 130 watts:

• 130 watts (measured) x 8,760 (number of hours in a year) / 1000 = 1138.8 kilowatt-hours.

• I pay 13.22 cents per kilowatt-hour for power in my area. So here's how I calculate my annual cost:

• 1138.8 kilowatt-hours * 13.22 cents / 100 = $150.54.

• Bottom line: I found that leaving my server on 24/7 costs me an extra $150.54 a year, which works out to $12.55 a month!

As you can see, such calculations are pretty simple, and the Kill A Watt was incredibly easy to use. Before this exercise, I had no idea what my server was costing me. But knowing what I know now, I had to rethink if I was willing or not to pay $12.55 a month for doing that—plus do something green for the environment. It was an easy decision for me—I was very willing.

Certainly, a large part of the cost for running my server could be saved by powering it down when it's not needed, but even more savings can be found with some of the simple tips I'll get into later on in this recipe. But first, I've included some sample costs directly following—which I think you might find interesting for comparison purposes.