Measuring Power Consumption?

rhadc asks: "Like many Slashdotters I have a pet network, spare parts around, and a number of configuration options. Unfortunately, I pay a power bill. I'd like to know how much power I'm using and how to optimize my numbers, but I don't know of any cheap way to find out. Would a 486 laptop be a better firewall than a 486 clone + UPS? Just how long will system X and system y with monitor z last on my my cheap UPS? Does anyone have insight into measuring this stuff?" For this, you can add up wattages on each device, multiply by some arbitrary "fudge rate" for local conditions, and get an approximate rate; or if you are electrically inclined, maybe you'd grab for the nearest ammeter and rig up a way to read what the line is drawing; but is there some device that could simply plug in between your UPS/Computer/Power Strip and the outlet and tell you? If not, how difficult would one be to build?

Like These?

[Anonymous Coward]

http://www.smarthome.com/9031.html [smarthome.com] or http://www.realgoods.com/shop/shop3.cfm?dv=3&dp=30 2&ts=1025344&kw=monitor [realgoods.com]

Re:Use the power companies meter, if you can.

[PD]

If you can't get everything in the house turned off, then get everything that you can, measure twice with and without your computers, and then subtract. You might find this helpful if for example, you've got a house alarm and no clue how to turn the damn thing off completely.

Wattmeter

[DiSKiLLeR]

but is there some device that could simply plug in between your UPS/Computer/Power Strip and the outlet and tell you? If not, how difficult would one be to build?

Yes. Its called an AC Watt Meter. You wrap the coil around any AC cable, and it'll tell you the amount of power drawn in watts....

D.

No they wont

[gruntvald]

The only UPS model(s) with any kind of intelligent monitoring are the Smart UPS series. But they don't give any indication of power consumption, only % load.

Re:Use the power companies meter, if you can.

[Kwantus]

be particularly careful to turn off things with themostats (refrigerators, a/c, freezer, water heaters, living-space heaters) or other self-regulators so you *know* their "contribution"o your measuree.

Use the power companies meter, if you can.

[ka9dgx]

If this is a home network, which you seem to imply, the most accurate measurement would be to use the very power meter which is being used to bill you with. You'll have to turn off EVERYTHING else in the house, then time a few rotations of the disk on the electric meter. If you can't turn everything else off, try to get a feel for the steady state by measuring everything else, then turn your network back on, and do the difference.

It usually tells you how many Watt hours a rotation is somewhere on the meter.

--Mike--

Borrow an industrial model for free

[green pizza]

Contact your local power company and ask to speak to someone in their 'consumer energy conservation' department, chances are they'd be more than happy to lend you such a high-quality meter for free. In fact, some will even offer to help you conduct the tests and offer further advice. While power companies are in the business of selling you electricity, it's good PR (and in some places -- especially California -- necessary) to help the average consumer conserve energy.

meter voodoo

[green pizza]

When I watch the little figures flash around on the LCD or the disk rotate (in the case of older meters) I can't help but wonder just how accurate the gizmo is. It would be very interesting to put an extremely sensitive meter on the house side of the power company meter meter to see how accurate it is. I hope the margin of error is on the customers side.

Ever thought about this: do you as the customer pay for the power that runs the meter? :)

APC UPS's will

[jsimon12]

Most decent APC UPS's will give you a power consumption figure if you use their UPS managment software (which is free for Linux). http://www.apcc.com/products/management/pcp_linux. cfm [apcc.com]. Or you could get a DMM and go a little ad hoc work yourself (don't know how electronically inclined you are, I would have to break out some college notes myself).

Re:Wattmeter

[schneidh]

A Wattmeter will only give instantaneous power consumption. One has to take into consideration high load times where the power consumption may be higher.

power consumption

[comtech7]

go to: http://www.backwoodssolar.com/. they have various meters, including wattage use. If you are looking to save energy, this is a good place to begin