how much electric bill can i save?

D

dopple

Gawd
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Oct 5, 2011
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685
my psu is 450w. my apc backups es650 india version (comparable to harsh environment version in usa) is 390w.
load on psu is 50-60 watts
load on ups is 80-90 watts.


since there is so much unutilised capacity i was thinking there must be a lot of power wastage going on.

atleast with CVTs/ferroresonant transformers such a load would result in 40-50% wastage of electrcity.
on top of that a computer PSU would waste 40% too for example http://www.newegg.com/Product/Product.aspx?Item=N82E16817103426 shows 65% efficiency in details

any thoughts?

should i downgrade to a 100watt psu and switch over to the simple surge protector?
 
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Capacity that isn't utilized doesn't translate into power wastage.

If the components of your computer pull only 50watts total, your total power draw from the wall will be 50 watts plus a small overhead for the PSU.

To answer your question - you would save little.
 
mda said:
Capacity that isn't utilized doesn't translate into power wastage.

If the components of your computer pull only 50watts total, your total power draw from the wall will be 50 watts plus a small overhead for the PSU.

To answer your question - you would save little.
Click to expand...


look at the efficiency figure - 65%
http://www.newegg.com/Product/Product.aspx?Item=N82E16817103426

even the best quality have efficiency ratings of 80% at full load, not to speak of lower loads.
 
That PSU you have linked is a peice of shit. While PSUs are generally most efficient at 50% load the quality of the PSU design has a far greater impact. A high quality PSU at 20% load will be more efficient than a shit PSU at any load.

Are those power figures in your initial post actual measured figures? if not then you need to get a meter and get some actual figures. Also it may sound silly but it's important to find out how much electricity actually costs where you are. When you are at such small amounts of power you can easily get into a situation where the power saved just isn't worth the cost of the savings.

As to the UPS any UPS will have an efficiency cost, you have to decide whether that cost is worth it in the face of your local power conditions.
 
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plugwash said:
That PSU you have linked is a peice of shit. While PSUs are generally most efficient at 50% load the quality of the PSU design has a far greater impact. A high quality PSU at 20% load will be more efficient than a shit PSU at any load.

But anyway i'd say the first thing you need to do is get yourself a "kill-a-watt" or equivilent. Until you know how much your current equipment is actually using it's rather hard to calculate your potential savings. Also it may sound silly but it's important to find out how much electricity actually costs where you are.

As to the UPS any UPS will have an efficiency cost, you have to decide whether that cost is worth it in the face of your local power conditions.
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ive given the stat for the best PSU you can find on newegg at 80% efficiency at full load, lower at lesser loads. that 200W PSU is not my PSU btw.

i've already given my power consumption stats in the ops, did i miss some figure? those are actual figures the cost per unit of electricity out here is INR 5.7. that is 0.1USD per unit.

i dont agree with you that a high quality psu is as much better as you claim, all PSUs work within certain set performance limits and a better one would simply hold the output at a more narrow and stable band vs a lower quality one which could fluctuate in its output more incase of harsher enviroment.

i'm wondering what kind of savings i can get?

i think i can get better efficiency from the psu if i route the monitor via the PSU instead of plugging it in the ups directly... that would increase the load on the PSU a little more = better efficiency= lower wastage?
 
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i'm currently operating at 20%(80W/390W) load on the UPS and 12%(54W/450W) on the power supply which is as bad as it gets in terms of power wastage... i'm probably wasting more power than consuming.
 
dopple said:
ive given the stat for the best PSU you can find on newegg at 80% efficiency at full load
Click to expand...
I dunno where you got that figure from but it's BS. 80 plus certification (which nearly all decent PSUs have theese days) requires a PSU to be over 80% efficient at load levels from 20% load to full load. The newer 80 plus bronze silver gold and platnium certifications have even higher requirements.

i'm currently operating at 20%(80W/390W) load on the UPS and 12%(54W/450W) on the power supply
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How exactly are you measuring those values?

the cost per unit of electricity out here is INR 5.7. that is 0.1USD per unit.
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Which means 100W for an hour will cost you 0.01USD. So 100W continuously for a year will cost you $87.66
 
I am completely confused by your posts.

80W/390 means that you're pulling only 80 watts, but the UPS can supply up to 390. It doesn't mean it's supplying 390 watts all the time and the 310 watts goes to waste, it doesn't work that way. Same goes for the power supply.

You don't know jack about power supplies, as is clearly evident in your posts. So don't try to argue with us. Power supplies are SUPPOSED to operate within certain standards, but not all do. A good quality power supply in addition to being MORE EFFICIENT has other better qualities as well.
1. Better voltage control = better system stability
2. Better ripple control = less potential for damage to your equipment
3. Better quality components = longer lifespan
 
plugwash said:
I dunno where you got that figure from but it's BS. 80 plus certification (which nearly all decent PSUs have theese days) requires a PSU to be over 80% efficient at load levels from 20% load to full load. The newer 80 plus bronze silver gold and platnium certifications have even higher requirements.


How exactly are you measuring those values?


Which means 100W for an hour will cost you 0.01USD. So 100W continuously for a year will cost you $87.66
Click to expand...

this article calls out some of the flaws in 80 plus certifications.
http://www.hardwaresecrets.com/article/Can-We-Trust-the-80-Plus-Certification/856

i measure those values using APC powerchute software.

ah i thought i was wasting 135W(450x0.3=135W. 30% inefficiency of 450W psu at 20% load) just on the psu and 117W on the ups assuming 70% efficiency. efficiency is lower at higher temps esp in a gaming rig. 70% efficiency is best case scenario in my non gaming rig.
total wastage of 252W... 3 times of what i'm using.
 
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Tsumi said:
I am completely confused by your posts.

80W/390 means that you're pulling only 80 watts, but the UPS can supply up to 390. It doesn't mean it's supplying 390 watts all the time and the 310 watts goes to waste, it doesn't work that way. Same goes for the power supply.

You don't know jack about power supplies, as is clearly evident in your posts. So don't try to argue with us. Power supplies are SUPPOSED to operate within certain standards, but not all do. A good quality power supply in addition to being MORE EFFICIENT has other better qualities as well.
1. Better voltage control = better system stability
2. Better ripple control = less potential for damage to your equipment
3. Better quality components = longer lifespan
Click to expand...

from what you say if i understand correctly then

maybe that means at 70% assumed efficiency i'm wasting the following amounts
ups load - 80W=70% ie 100%=114W is being used i.e. wastage of 114-80W=34W
psu load - 55W=70% i.e 100%= 79W is being used i.e. wastage of 79W-55W=24W

while i'm consuming 80W at ups my total wastage is of 58W at 70% efficiency(best case scenario). so my wastage is equal to approx 75% of my consumption.

from the calcs on average i think any rig consumes as much power as it wastes.
 
oh and ups consumes 10watts for battery charging of the UPS, this is not a wastage but incase i use a surgeprotector only instead of a ups i save 34W(from previous post)+10W=44watts.

the wastage is limited to the psu alone then at 24W.
 
1. Combine your posts, don't post multiple times. If you need to change something, edit the last post you made, don't make a new one.

2. The 80+ certification may be flawed, as was written in a sticky in this very subforum. However, there are power supply manufacturers that do go by it, and testing has been done to show whether or not retail units comply with the 80+ certification. And you can find many of those reviews on this very site.

3. Good power supplies are at least 80+ certified. That means they will get at least 80% efficiency at almost all load levels besides really low ones, 10% or less.

4. Software readings are EXTREMELY inaccurate.

5. Who said that UPS have an efficiency of 70%? Where are you getting those numbers from besides inaccurate software readings? Most UPS pass the power directly from the wall to the power supply, so there's minimal waste there.

6. A power supply that consumes as much power as it puts out would be considered 50% efficient. There are no good power supplies that are 50% efficient. And you can buy power supplies that are up to 85% efficient or higher.

7. Try reading some of the stickies in this forum. I REPEAT, READ THE STICKIES IN THIS FORUM.

Edit: 8. You STILL haven't told us the specific model and manufacturer of your power supply.
 
1. Combine your posts, don't post multiple times. If you need to change something, edit the last post you made, don't make a new one.

ok

2. The 80+ certification may be flawed, as was written in a sticky in this very subforum. However, there are power supply manufacturers that do go by it, and testing has been done to show whether or not retail units comply with the 80+ certification. And you can find many of those reviews on this very site.

ok

3. Good power supplies are at least 80+ certified. That means they will get at least 80% efficiency at almost all load levels besides really low ones, 10% or less.

can you give me a link for this please? where 10% 20% loads are tested in a graph.

4. Software readings are EXTREMELY inaccurate.

the last time i had measured the readings were close enough to the multimeter readings. i'm open to you providing some more info on this. that would be nice.

5. Who said that UPS have an efficiency of 70%? Where are you getting those numbers from besides inaccurate software readings? Most UPS pass the power directly from the wall to the power supply, so there's minimal waste there.

i've given the link to the nonharsh environment UPS from APC website. I have a harsh environemnt ups and it is rated at lower efficiency on the website itself. The ups i have is an online UPS i.e. it doesnt pass on the power directly to the PC.

6. A power supply that consumes as much power as it puts out would be considered 50% efficient. There are no good power supplies that are 50% efficient. And you can buy power supplies that are up to 85% efficient or higher.

well i just proved that with the calcs. those 85% efficiency psus are all that when brand new and in a lab environment. real life figures would be nice, which i'm assuming to be on the lower side since this is not a marketing gimmick

7. Try reading some of the stickies in this forum. I REPEAT, READ THE STICKIES IN THIS FORUM.

umm you don't need to shout. doesn't make your points more valid not that i have anything against you. i'm just interested in a real life figure of power savings and the best way to achieve them, not sure why you're getting so touchy. take it easy.

Edit: 8. You STILL haven't told us the specific model and manufacturer of your power supply.
no one asked. it is Corsair CMPSU-450VX
 
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