# Thread: 480w PSU - Annual Costs

1. ## 480w PSU - Annual Costs

I was just wondering how much it costs to have a 480w PSU running 24/7 for a year. Does it depend on load or does it use 480w whether you've got 1 HDD or 12? Is there a calculator somewhere that figures this out?

Bit of a random question I know, but I'm going to be moving out of my parents and in with my girlffriend soon so will have to start paying the electricity bill myself.

Any thoughts would be great.

2. Having a 480W psu is no more expensive than an equivalent (same brand) 350W psu...it's just about the components you have and the efficiency of the unit...just because it's a 480W psu doesn't mean it actually uses 480W!

3. Around &#163;295/year if it's actually using 480W.

4. I worked it out once it was around &#163;1/week on 24/7 depending on the total wattage of the components.

5. Say you're using 200w on an average second that would be 0.2p per hour roughly.

24/7 would be 4.8p per day, 33.6p per week and &#163;122.64 per year.

6. I may be being silly here, but if it's 4.8p per day and 33.6p per week from the post above then it would be &#163;17.52 per year, not &#163;122.64?

Sorry if I'm missing something,

ShMeE

7. Originally Posted by Dark Horse
Say you're using 200w on an average second that would be 0.2p per hour roughly.

24/7 would be 4.8p per day, 33.6p per week and &#163;122.64 per year.
D:\WINDOWS\system32\calc.exe

8. Must have pressed a wrong button somewhere...

Anyway its not on my D Drive, that'll be where I was going wrong

9. probably :x

10. Originally Posted by Dark Horse
Say you're using 200w on an average second that would be 0.2p per hour roughly.

24/7 would be 4.8p per day, 33.6p per week and £122.64 per year.
Where do you live that 1KW/h costs 1p?!

11. Oh dear, must really not have been paying attention...

&#163;175 makes much more sense.

12. Ok thanks for that.

13. Costs nowt....

14. Not from a street light? Tsk!

15. Originally Posted by cptwhite_uk
Having a 480W psu is no more expensive than an equivalent (same brand) 350W psu...it's just about the components you have and the efficiency of the unit...just because it's a 480W psu doesn't mean it actually uses 480W!
Not strictly true.

A PSU is not as efficient at low load. A higher rated PSU is further from it's greatest efficiency than a lower rated PSU. My PC spends nearly all it's time at ~100W whilst surfing etc, and only cranks up to ~250W when playing a modern graphics intensive game.

It isn't a huge effect, but was enough to deter me from buying anything more than the bottom of the range 375W PSU I have (given that I will never be able to afford SLI 7800 cards and so don't need that flexability).

16. Originally Posted by Butcher
Not from a street light? Tsk!
Don't worry, I'm running that shed from a streetlight anyway