Have you ever thought about how much it cost to run your PC -- the one you're using to read this article? What does it cost to play games, surf the Internet, or download files? It all costs money -- money that you, your parents, or whoever is in charge of the monthly electricity will have to pay. Those of you in charge of paying this bill will surely be interested in keeping costs down, which is why you might want to pay a little more attention to what sort of hardware you are using in your computer.

Many users -- especially computer enthusiasts -- put together a new PC that can easily handle any task, without much thought for power efficiency. If you intend to use the computer primarily for gaming, buying a high-end processor and graphics card makes sense. Likewise, if you intend to do complex three animations or movie encoding, you'll probably want to have as much processor power as possible. If all you're going to do is watch movies, run Microsoft Office, and surf the Internet, you're not going to put a big load on any of the components. In that case, your PC will typically be idle and waiting for user input, while any high-power components will still go merrily along sucking down extra power.

We recently looked at the topic of power consumption for each component in the PC. Of course the numbers were merely a rough estimate for our specific setup, programs, and tasks, so that article could serve as a baseline for the amount of power your system might require. We also discussed how power requirements affect the type of power supply that you will want to purchase. In this article, we want to focus more specifically on the costs of running a computer (not counting anything like broken components and upgrades). We look at electricity prices in the US and Europe to calculate how much various types of PCs actually cost to run. Perhaps you're one of those people with multiple systems -- one for gaming, one for office work, maybe one or two for the kids, and perhaps a few extras running distributed computing tasks 24/7. We will look at several different workloads to see how much various types of systems actually end up costing on a hourly, daily, and yearly basis.

KWh prices in the U.S and EU

When we started researching prices of electricity (measured in kilowatts hours/kWh) for the different countries, we were surprised by the huge differences in price. In the US prices range from $0.05 to $0.21, according to the Energy Information Administration -- the average price is $0.089 per kWh. European prices are different for each country, so we will just take Germany as an example. Prices there are high relative to the US but about average for Europe. In 2008, Germany has an average of 17 to 22 Cents (€) -- about $0.22 to $0.29 USD! That's anywhere from 1.5 to 6 times as expensive in the old world depending on where you live; obviously, areas where costs are higher will probably be more interested in PC power consumption, but that is a separate issue from what we are looking at today.

Calculating Power Requirements and Costs


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  • 7Enigma - Monday, November 17, 2008 - link

    I think you mean 1/2. Most of these charges are regardless of actual power used. Things like transmission charges, local/state taxes, "improvement" fees all will be the same each month whether you draw 100kW or 10. Where the savings *can* become more than stated is if your local utility uses a stepped price plan. That is to say you pay $X up to 500kWh's, then a higher rate after that level. This is how my bill is done unfortunately. I was under the impression there was some sort of peak hour price and another price for off-peak (as many places have). This can be taken advantage of by doing high energy tasks like the washer/dryer/dishwasher/ect. at night or early in the morning where you may be paying anywhere from 20-50% less for the same amount of power. With flat rate stepped plan you cannot benefit from using off-peak, and in general wind up paying more for your energy since they don't care if you used that 1000wh at 3am or 5pm.

    Everyone should check their bill statement and look to see how they are being charged. If you have a stepped plan like mine you may benefit more from being more energy conscious than if you have typical peak/off-peak pricing.
  • raWill - Saturday, November 15, 2008 - link

    Infact I have thought about it - I'm so glad I got rid of my 8800GTS, what a pointless consumer of power when all I do is surf the net 90% of the my computer is on.

    Even worse is people that leave thier sli systems on whilst downloading torrents, etc.

    By managing my standby power sources (turning them off every night before bed) and only downloading torrents and such whilst I am using the computer I saved about $20 a month in electricity. I live on my own too!
  • mongo lloyd - Friday, November 14, 2008 - link

    PSU efficiency will always be higher in Europe than the US due to 240VAC. I didn't see you adjusting for this, but granted, I only skimmed the article because my electricity bill is baked into my rent. Reply
  • ggordonliddy - Friday, November 14, 2008 - link

    It's okay, Osama will pay for it. I mean Hussein. I mean Obama. Reply
  • atm - Friday, November 14, 2008 - link

    Thanks for posting this article. Without the monitoring equipment at home, I was in the dark about true system power draw. Reply
  • ytsejam02 - Friday, November 14, 2008 - link

    I am all for saving energy. I have 3 computers in my house (laptop, desktop, and htpc), and both the htpc and desktop are running 45W cpu's with the Western Digital Green Power drives, and using the onboard graphics and sound. I run all the programs I need with that, so I hope I'm doing something right with these configurations, and that they are low power consumption.

    Now my problem. How much energy would be required to recycle a constant PSU turnover? I'm sure it wouldn't be constant, but I've no idea what it would cost, so I'm thinking in generalities at the moment.

    Either way, I'm guessing that would eat into a large part of the overall global energy problem.
  • IcePickFreak - Friday, November 14, 2008 - link

    I'm waiting for PC Power & Cooling to release their 10MW fusion reactor PSU. No longer will I be tethered to a power outlet or subjected to power outages.

    As a bonus, think of the m4D 9AM1nG 5ki11z I'll have when I sprout a third arm!
  • Carnildo - Monday, November 17, 2008 - link

    I'm afraid you'll be disappointed, then. Fusion reactors don't cause mutations. Reply
  • chenedwa - Friday, November 14, 2008 - link

    Could anyone estimate the cost of a typical laptop setup? Many will keep the laptop's adapter plugged-in 24/7 regardless of whether the computer is attached. Reply
  • strikeback03 - Friday, November 14, 2008 - link

    Using a Kill-A-Watt for measurement, my T43 with 15" S-IPS screen, Pentium M 1.86, ATi X300 graphics, 2GB RAM, and 100GB 7200RPM HDD uses 11W at idle with the lid closed, 18-21W at idle with the screen on (depending on brightness) and about 40W under load. Other laptop reviews on the site here offer power consumption numbers as well. Reply

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