These days people seem to care more about pelican welfare and wasted watts than in the good old days of wanton squander. That's a good thing, I guess.*After all, pelicans don't bounce back the way The Fat Controller did. That guy was badass.
Our computers may not be be the primary culprit behind the world's fossil fuel depletion problem, but they sure don't help. What can we Mac users do to minimise our impact on the globe's pleasant green hue? Plenty.
Energy Saver: Use It
Ok, I'll be the first to admit my laziness here. I don't like getting up and waking my iMac every time I want to stream media from it, so historically I've left it on all the time. But thanks to a recent change of heart and some great new Energy Saver features in Snow Leopard, I'm starting to change my ways.
Energy Saver is Apple's dead simple already-on-your-Mac solution to going a little bit green.*You can use it to set your Mac to sleep when left inactive for a number of minutes or hours, or schedule it to automatically sleep or wake at a time of your choosing. The options here aren't particularly advanced (you can't set multiple sleep/wake schedules for a single day, for example) but they're a great start and should fit the needs of most users.
Sleep
Let's start simple. Set your Mac to go to sleep automatically after a length of time (of your choosing) in Apple Menu > System Preferences > Energy Saver.
Sleep is a bit like Standby on Windows and offers near instant-on when you press a key to wake your Mac back up. This is step one to greening up your Mac.
Hard Drive Sleep
Tick the box below to save some extra power by allowing energy saver to spin down hard drives when they're inactive for ten minutes:
Note that frequent starting and stopping of a hard drive can lead to unnecessary wear and tear on the drive's internals, leaving this preference up to user discretion.
Wake On Demand
This is my favourite. There's a new feature of Snow Leopard called Wake On Demand which may mean you won't have to leave that main home machine on all the time for access to things like printers, iTunes libraries, file sharing or even screen sharing. It requires an Apple wireless router (Airport Extreme or Time Capsule running at least firmware v7.4.2) but if you have the right hardware, Snow Leopard is very smart about it. If you request something that requires the host Mac to be awake, Wake On Demand simply wakes it up, allows the operation to be performed, then puts it back to sleep. This is all managed by a Bonjour service called Sleep Proxy.
There are even third party applications jumping on this feature to make your sharing experiences more efficient. This is particularly useful for Media Centre applications where you want anytime access to your shared movies or music without having to leave your media server on full time. This has singlehandedly cut down the powered-on time of my iMac media server to about 20% of what it was before Snow Leopard.
To activate Wake On Demand, open Apple Menu > System Preferences > Energy Saver and tick the box 'Wake for network access':
Hot Corners for Sleep Display
Here's a great habit to get into. Every time you walk away from your Mac, just drag to an Active Screen Corner you've set up to put your display to sleep.*To turn on Active Screen Corners, open*System Preferences from the Apple menu and click Exposé & Spaces. Under the Exposé tab, choose a corner and select Put Display to Sleep from its drop down menu:
This will save you about 20-30W on a 21.5 inch iMac compared to leaving it idle with its screen lit.*I love Active Screen Corners but I've found it can be very confusing for other users of your Mac (especially first time Mac users); if they're sloppy mouse or trackpad operators they may frequently drag off screen and be thrown off completely when Expose tiles all their windows or the screen turns off for no reason apparent to them. I don't like to give first-time Mac users the impression that Mac OS X is a foreign system that does strange things.*If you care enough to prevent this, you can add a function key requirement to each active screen corner. When you're browsing a corner's drop down list, just hold Shift, Control, Option or Command while making your selection to make that function key a requirement to*activate the corner.
Retire Your Discs
In 2010, we can live without physical discs the vast majority of the time. Installing software, listening to music or watching movies directly from disc is taxing on your system in terms of power and heat and should be avoided whenever possible. You think your MacBook has a 10 hour battery life? Try watching a couple of movies straight from DVD and see how long it lasts. You'll get a strange burning sensation in your lap and a low battery warning in no time.
As a long term solution, ripping all your CDs and movies is a great way to make them available to other Macs or devices like iPhone, iPod or iPad and reduce the power-wasting effects of discs. This also helps the discs to be kept in great condition or even leant to friends without you having to go without its contents. Click here for MacTalk's guide to ripping DVDs to H.264 movie files, which are widely supported on Apple devices and hardware-accellerated on many models which leads to power savings in itself (as your CPU doesn't take such a thrashing from the decoding process).
Downloading device software (printer drivers etc) instead of installing from disc is also a great way to ensure you're getting the latest software version on first install.
Buy an iPad
?This might seem like an odd suggestion but it's one sure way to knock your computing-related power usage concerns on the head. The iPad is basically an enormous battery with a screen, which means it lasts for ridiculous amounts of time between charges (12-14 hours of full time use, or 3-4 days for average users) and even when it's charging from a wall socket it only draws 10W. Most of what you usually want to do on your Mac can probably be done on iPad in an orgasmically enjoyable way and whenever you really need the abilities of Mac OS X you can wake your existing Mac from its slumber. The best of both worlds, indeed.
Apple's low power Mac OS X-running champions, the 13" MacBook, 13" MacBook Pro and Mac Mini are worthy of mention, too. These very capable machines waste very little power and (for laptops) offer excellent battery life.
Five Quick Ways to Green Up Your Mac