Low Impact

By which I don’t mean “politically correct” power consumption, but rather the power consumption of the computer you’re sitting in front of right now!

Computers have become a standard appliance in a lot of households, and it can be surprising just how much power they use. The amount varies widely from machine to machine and how hard it is “working” – a PC sitting unused consumes a lot less power than a PC busy churning out the graphical special effects for the latest game – but modern machines often consume somewhere between 120 – 400 watts.

That’s a surprising amount of power – well and truly up there with the household big-screen TV. A basic home computer that is only used for 2 hours a night for non-intensive tasks (so lets assume 130 watts) would end up using almost 100 KwH a year – that’s 100 kilograms of CO2 emitted into the atmosphere for the majority of Australian consumers whose power is sourced from coal power plants. And that’s the low-end of the scale.

In fact, its not uncommon for a computer to be left on 24 hours a day. Perhaps it’s annoying to wait for the computer to boot up, so the kids just turn the screen off when they’re done. Or perhaps the computer needs to be left on all day because it acts as a webserver, email server, or file server. Whatever the reason, that same low-end computer discussed above would use over 1100 KwH each year if left running all day – over 1 tonne of greenhouse gasses, and more than $110 on your electricity bill (assuming you pay around 10c/KwH).

There’s a few things you can do to reduce your computer’s power consumption. The first, and most obvious solution is the same as for every appliance in your household – turn it off when not in use! Its a simple technique, but an effective one. Additionally, modern computers sometimes offer a half-way solution in the form of a “standby mode”. In standby mode, the computer will use a lot less power than normal (around 10 watts), but it will boot up and return to the state where you left it more quickly than turning it on from scratch. Practically all laptops have this feature, but it can be found on desktop systems too.

Laptop computers are an increasingly common choice over the more traditional desktop PC for many households. Families like the portability of it – they can be set up on the table to do the tax return, then carried into the living room to do homework. As an added bonus, laptops usually use a lot less power than a desktop system – they’ve been designed to be able to run off batteries, and the lower the power requirements, the longer the battery will last.

It’s also important to make sure that your computer is appropriate for your needs. While a hardcore gaming fanatic may need a high powered computer to run the latest games, a more casual user who mostly surfs the net and reads their email can make do with a far more modest machine – in general, the less powerful the computer, the lower its power consumption.

In fact, if you look hard enough, you can find “green” computers which have been designed to use as little power as possible. The picture above is of a “Book PC” – the same computer that currently runs this website. It’s powered by a VIA Eden CPU (the main processing unit in a computer). This is just like the more standard AMD or Intel chips but it uses a lot less power – while normal CPUs might use from 60 to 100+ watts, the Eden chip only uses around 7 watts!

This comes at a cost – the Eden CPU is a lot slower than a standard CPU – but brings a number of advantages. Not only are the power bills lower and less climate-changing emissions being produced, but that low power consumption means that it doesn’t need a fan to cool it down. A silent PC is an eerie thing when you first encounter it!

The Book PC that powers Low Impact is a great example of one of the power saving tips above – picking a computer that meets your needs. While the Eden CPU isn’t going to win prizes for raw speed, Low Impact isn’t like Google – it doesn’t need to service millions of web pages per second. Of course, as Low Impact becomes insanely popular, we may need to look at upgrading!

Categories: efficiency, energy, environment, green, reduce

Tags: computer, efficiency, power consumption, reduce