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The Australian Department of Climate Change advises that a laptop computer used for 5 hours each day generates around 40 kilograms of greenhouse gas each year.

Desktop computers used for the same amount of time can generate between 200 and 500 kilograms green house gases.

With Australia having signed the Kyoto Protocol, the time has come for us all to do our bit to reduce green house gas emissions. It’s not hard – we did it with water consumption, so we can do it with energy. It’s just about making the right consumer choices.

Even if you are a green house sceptic, there is a good economic argument - reducing energy consumption will save the average consumer hundreds of dollars each year in electricity costs.

During average computing, a system may consume approximately 240W of power at a cost of 3.7 cents per hour, but when playing a 3D game for several hours, the power usage peaks upwards to approx. 600W of total power at a cost of 9.3 cents per hour (based on current Origin Energy household supply rates).

Assuming that a typical desktop computer is used for an average of 5 hours each day that means the total cost of electricity over the full year will be $675.25 during average computing and peaking to a staggering $1697.25 at high usage rates. For anyone operating a business, that becomes a very significant amount of money when multiplied by the total number of computers operated by the organisation. Google are probably one of the biggest users of desktop computers on the planet; they take the issue so seriously that they are investing millions of dollars in developing more efficient energy sources.

With a little human ingenuity it should not be hard to reduce the energy consumed by computers substantially. The solution is a combination of hardware, software and humanware:

Hardware solutions:

A PSU converts the 110/240V incoming AC power from the main electricity supply down to the 3.3, 5 and 12V DC power levels required by the various internal circuits and components that make up a modern computer system.

Reducing voltages from one level to other results in loss of energy in the form of heat creation during the conversion, which means that the amount of power in watts consumed by the power supply will be greater than the amount of watts supplied to the internal components. This heat creation is why most power supplies require fans to cool them.

The efficiency rating of a power supply determines how much energy is wasted or lost when it converts the wall outlet power to the internal power components. For example, a 75% efficiency power supply that generates 300W of internal power would draw roughly 400W of power from the wall. The important thing to note about a power supply is that the efficiency rate will vary depending upon the load amount on the circuits as well as the condition of the circuits.

In order for new power supplies and PCs to meet the new ENERGY STAR '80 plus certified' requirements, they must meet an 80% efficiency rating across all rated power output. This means that if the computer is running at 1%, 100% or any level in between, the power supply must reach a minimum 80% efficiency rating in order to get the label.

When buying a new PC, it is critical to look for the ’80 Plus certified’ rating. This may cost a few dollars more, but the extra cost is easily offset by the improvement in energy efficiency and the overall performance and reliability of the system. You are doing yourself a favour because most power supplies priced below $75 generally do not meet the power requirements of the latest processors. To make matters worse, the components used in them are of inferior quality and more likely to fail over time. While they may power the computer system, inconsistencies in the power to the components can cause instability and damage to the computer.

Manufacturers of computer CPUs  are working hard to produce low energy consumption products that will be less harmful to the environment. Leading the way by several lengths is VIA with their MM3500 series motherboards with integrated Via CPU. Consuming just 20 watts at peak power and an incredible 1 watt on idle; the manufacturing process is also carbon neutral as the company invests in carbon offsets.

AMD have not shirked the challenge with their new range of 45 watt AM2 desktop CPUs, but Intel is trailing in the power consumption stakes. Their Core 2 Duo Desktop CPUs consume approx. 60 watts of power, which is the equivalent of a standard light bulb. However, honour is restored by the Intel Centrino Duo range of laptop CPUs as they consume just 35 watts, making them ultra energy efficient. Mobile CPUs are also finding their way into desktop computers - the iMac uses an Intel Core Duo mobile processor.

LCD monitors are another way to reduce power consumption as they use much less power than previous generation CRT monitors. A typical LCD monitor only uses 25-30 watts of power compared with 100-150 watts consumed by a CRT monitor.

All our desktop PCs are supplied with Antec 80 plus certified power supplies or better.

Our ECO Essentials 1 Desktop system is one of the most energy efficient computers on the planet and each component in all our systems is selected to maximise energy efficiency.

Software solutions:

All versions of Microsoft Windows have power management features that can be accessed by via the Power Options in Control Panel or right mouse click in a blank area of the desktop and select Options in Windows XP or Personalise in Windows Vista.

In Windows XP select Screensaver and turn off the screen saver is this is a complete waste of processing power. Then select Power options in the same window. I recommend that you set the monitor and hard disk drives to turn off after 15 minutes of idle time and set the computer to go into hibernation after 30 minutes (when in hibernation the computer is effectively off, but the current status is saved to the hard disk drive).

In Windows Vista, select Screensaver and turn it off. Then select ‘change power options’ in the same Window and select the Balanced Option (Power Saver mode seems to over throttle the CPU resulting in a dramatic fall in performance). The select ‘Change Plan Settings’ and set the monitor to turn off after 15 minutes and the PC to hibernate after 30 minutes

If supported by your motherboard, you can also set the PC BIOS to store current system memory in the RAM rather than the hard disk drive for faster recovery from hibernation.

These are all the standard settings we use when supplying a PC to our customers.

Humanware solutions:

It’s simple, it’s easy and it’s within your power - switch computers and equipment off when they’re not in use. This improves energy efficiency, cuts greenhouse gases, extends product life and avoids a potential fire hazard.

It is difficult to give an accurate measure of the energy and green house emissions savings to be made by adopting all these measures, but we would estimate at least a 50% if you purchase a low energy PC such as our $999 ECO Essentials 1 model or an ASUS laptop.