Saving electricity by turning computer off?

phildamb

espresso wrote: »

Not another OWL user are you?

Nope I go out and look at the meter.

espresso

phildamb wrote: »

An example is that I have a 650Watt (output) rated power supply. Its supposed to be roughly 80% efficient so under full usage (which mine does due to graphics card and numerous drives inside) Im probably using about 800+Watts (from the mains) in an hour, so its costing me about 10p an hour to run my machine.

Your quoted example is not the norm, as most typical desktop PC's with a 500W PSU and including a monitor use less than 150W. I know that mine does as I've checked it with a power meter.

Cardew

This has been covered hundreds of times in lots of forums and espresso is correct.

My dual core PC rarely uses more than 150 Watts - measured with a power meter.
Also a laptop is normally around 30 Watts in use, but might be higher when charging a low battery.

Phlik

OP, your hubby is right, turn it off when you're not using it.

I've been using a monitor to keep an eye on my media centre set up.

When the PC is off it uses 0.008 kwh

When first powered up it peaks at 195w for about 2 seconds before settling back to 125-130w whilst loading the operating system (windows MCE). Whilst watching TV,DVD's, recording, playing games etc it stays around 125-130w.

Hibernate sucks, 76w or 0.076 kwh.

Phildamb, what PC have you got? deep blue?

Phlik

amcluesent

I've now measured the wattage of some electrical items and worked on the costs of 'always on' stuff. NB I've assumed approx. 20p per KWh - a high tariff so you can adjust in proportion. All these costs are PER QUARTER assuming the item is left in operation 24*7:

Cable MODEM, 5W, £2.90
Wi-Fi Router, 6W, £3.48
PC/LCD monitor (S3 Sleep mode[no fans]), 5W, £2.90
TV/PVR (standby), 11W, £6.38

Now for the Wattage of stuff when on in normal way, and the PENCE PER HOUR:

Tower PC/LCD monitor, 170W, 3.4p
TV/PVR, 80W, 1.6p
Laptop on charge, 45W, 0.9p

Note that the Sleep mode (it's a Vista machine) is the so-called S3 ACPI mode which I set in the BIOS. By default it used S1 mode, where the fans stayed on - this mode consumed 80W! I just need to tap the space-bar and the machine is ready to use in <10 seconds.

greenbee

Try an eco-button http://www.eco-button.com/uk/A2.1.home.htm to hibernate easily (you don't have to think about it, just press the button). The software that comes with it lets you know how much money you have saved by hibernating. However, you should be aware that hibernating and even shut down PCs can still draw energy (I've recently measured 26 watts on a shut down PC!). This is the best bet for reducing energy usage during the day, but at night, switch the PC and all peripherals/accessories OFF at the mains! (After shutting them all down properly) I've had surface mounted sockets put on the wall behind my desk so they're easily accessible, and have seen my electricity bills plummet as a result.

1carminestocky

greenbee wrote: »

Try an eco-button http://www.eco-button.com/uk/A2.1.home.htm to hibernate easily (you don't have to think about it, just press the button). The software that comes with it lets you know how much money you have saved by hibernating. However, you should be aware that hibernating and even shut down PCs can still draw energy (I've recently measured 26 watts on a shut down PC!). This is the best bet for reducing energy usage during the day, but at night, switch the PC and all peripherals/accessories OFF at the mains! (After shutting them all down properly) I've had surface mounted sockets put on the wall behind my desk so they're easily accessible, and have seen my electricity bills plummet as a result.

This site as been tailored for domestic home users, business users can switch to the 'business site' by clicking the link above.

You'd think that a company launching a web site would actually make sure they got their spelling spot on, wouldn't you? :rolleyes: Looks like a good idea, though.

amcluesent

£14.99 seems a lot to pay when most PCs will go into sleep mode just by pressing the power button!

greenbee

Don't be fooled into thinking that you save much energy in sleep mode. Hibernation is generally much more efficient. The ecobutton site has a saving calculator on it to help you decide whether it is worth it.

You can alter the energy saving settings in the OS, and you should be able to find documentation on what your PC/laptop uses in different modes. Modern equipment should be reasonably efficient in all modes, but hibernation uses less energy than sleep/standby.

Mind you, we've just tested some kit at work, and it draws 26 watts when its OFF!!! :eek: And because we have to do overnight patching, we can't switch off the socket - which is what I'd recommend you do at home if you know you're away for long periods/aren't in a rush to start up when you get back.

amcluesent

>Don't be fooled into thinking that you save much energy in sleep mode.<

One of those plug in power monitors is really needed with lecky so expensive. I found that a tweak in the BIOS dropped the 'sleep' wattage down from 80W to 5W.