Electricity Use

[freeztar]

I decided to purchase a Kill-A-Watt unit to test my electricity consumption. It's a very nifty device, capable of measuring volts, amps, hertz, KWH, etc. I plugged it in today (in KWH mode) and plugged my laptop computer's power strip into the unit. Below are some semi-cursory results:

 

Time..... KWH

16:21.... 0.00 (start)

16:27.... 0.01

16:34.... 0.02

16:41.... 0.03

16:48.... 0.04

...

18:25.... 0.17

 

Assuming an electricity rate of 9.85 cents/KWH in Georgia Jul-07:

 

~7.3 minutes per one-hundreth KWH

~730 minutes (~12.2 hours) of laptop computer usage = 1 KWH

10 KWH = ~122 hours of laptop computer usage = ~$1.00

 

That really took me by surprise!

I expected it to be much, much higher.

 

I'll be testing more electrical objects such as a space heater, refrigerator (1/4 size), microwave, etc.

 

Does anyone have their own results to post? :evil:

 

Laptop specs:
Sony VAIO PCG-K37 (sucks, don't ever get one)
P4 3.2GHz 1MB CDDVDRW 40GB EIDE 
USB 4-port hub with: 2 USB drives, wireless mouse reciever, 
 and a laptop cooling pad with three fans
Power supply: 19.5V

[Jay-qu]

I dont have any results I just remember running some similar calculations and been equally surprised as you are :evil:

 

My mum was complaining about people leaving lights on and how it was costing us more, so I went and calculated how much it would cost to leave all the lights on in the house for the duration of the billing period its nothing compared to what the microwave, fridge and computers use.

[Turtle]

Waste not, want not. It all adds up. I don't have a meter, but I do keep tabs on what the rated wattage/amperage is for our juice-hungry friends. The refer is the first thing I'd downsize if I lived on my own, and I would unplug Micro, vcr, etcetera things that use a "little" juice all the time. I'm a freakin' miser OK!? :eek: :hyper: I turn off lights behind roomies(sometimes I don't even wait for them to leave a room!:eek:), turn the thermostat down, & burst into the occasional "I'm not payin' for your waste" rant, among other miserations. :eek2::eek::D

 

 

Any body remember Reddy Kilowatt?

 

Have you found any great variance between rated power-use and actual? :phones::

[freeztar]

I dont have any results I just remember running some similar calculations and been equally surprised as you are :eek:

 

I thought the unit was not working for the first seven minutes until I saw the LCD display change from "0.00" to "0.01". It was a momentous, and illuminating moment. :hyper:

My mum was complaining about people leaving lights on and how it was costing us more, so I went and calculated how much it would cost to leave all the lights on in the house for the duration of the billing period :phones: its nothing compared to what the microwave, fridge and computers use.

 

Indeed.

I'm sure most lamps pale in comparison to "heavy loaders" such as washers, as far as energy consumption is concerned. Nonetheless, it is prudent, IMHO, to turn off lights that are not being used. Less is more in this case! :eek2:

 

I'm now at time 21:45 and showing KWH 0.44.

[Jay-qu]

I thought the unit was not working for the first seven minutes until I saw the LCD display change from "0.00" to "0.01". It was a momentous, and illuminating moment. :phones:

 

Indeed.

I'm sure most lamps pale in comparison to "heavy loaders" such as washers, as far as energy consumption is concerned. Nonetheless, it is prudent, IMHO, to turn off lights that are not being used. Less is more in this case! :eek:

 

I'm now at time 21:45 and showing KWH 0.44.

Of course I would not condone wasting power for the sake of it - it may be cheap but it is still pumping CO2 into our atmosphere.

[palmtreepathos]

My past wanton extravagance was the use of LIGHT! wonderful, beautiful lamps and lights! I feel that a well lit home is a welcoming place. I grew up with the meter miser, harp harp harp! I AM WORTH IT! I need it and of course, it is cheaper than a shrink... and meds... :phones:

 

Also I am in the process of adjusting to new energy lights UGH! ugly color casting swirls. But I am trying. In the reading room we had a 500 watt halogen lamp, ahh sweet light! It is being replaced with a combo of regular 26 watt swirls and true color 26 watt swirls, 2 each so far for 104 watts, it is not the same but we are getting used to it. I am trying to do my part. And I like the idea of these lights...

YouTube - Hybrid Solar Lighting http://www.youtube.com/watch?v=hQ5MiLqb5VE

 

Sorry, but sometimes you just gotta "lighten up!" :eek:

[Ganoderma]

cool video, those types of lights were a long time coming. i am so glad this sort fo thing is starting to be sold..

 

when i lok a tmy powers usage, aside form looking at the label, i always think in my head "Hot=lots of power". things like heaters, stoves, dryers etc i really try to cut back on. so things like hanging clothes to dry, using high L/W lights (i replaced all my lights in the house/school with 91L/W flouros! ohhh yea lol.

 

 

where did you get that meter? i always looks at the meter on the house that goes round n round. but i think it would be cool to measure the actual power usage of individual things (cause i am sure at least one of the labels on our stuff is misleading haha)

[CraigD]

I decided to purchase a Kill-A-Watt unit to test my electricity consumption. It's a very nifty device, capable of measuring volts, amps, hertz, KWH, etc.

It sure is! :eek_big:

 

I got a Kill-A-Watt last year, and used it to check various stuff around my house. I also took it with me when I shopped for and eventually bought the below mentioned LCD TV. There are some surprising differences between similar-specification TVs, some drawing more than twice the power of one of the same size and display type.

Does anyone have their own results to post? :hyper:

Interesting measurements from around my house include:

• Sony CFD-E90 “boom box” Radio/Tape/CD player, using AC power
  • Off: < 1 W
    
  • Radio on, low volume: 1 W
    
  • CD on, low volume: 5 W
    
  • Max volume: 9-14 W
    

  [*]2004 Toshiba A65-S126 laptop, 2.8 Ghz Celron, 1 GB RAM, w/ 2-fan cooling pad

  • Hybernating: 0-1 W
    
  • Sleeping: 29-30 W
    
  • CPU ~ 0%: 41-45 W
    
  • CPU 100%: 76-78 W
    
  • CPU ~30%, disk write bottlenecked: 49-55 W
    

  [*]JVC AV-27D303 27” CRT TV

  • Off: <1 W
    
  • On, no signal: 55 W
    
  • On, signal: 60-90 W
    

  [*]DCT2224/1161/ACDEQ Cable TV receiver box

  • Off: 18 W
    
  • On: 20 W
    

  [*]40” Samsung a900 LCD TV

  • Off: <1 W
    
  • On, no signal: 70 W
    
  • On, signal: 180-240 W (The whiter/brighter the picture, the greater the power)
    

  [*]Mr Coffee 12 cup coffeemaker

  • Brewing: 950 W
    
  • Warming: average about 200 W, in 15 s bursts of 950 W
    

Light bulbs of all kinds (incandescent, florescent, etc.) all appear to draw almost exactly their rated power.

 

A typical personal electronics (cellphone, etc) charger draws a few watts when charging, essentially 0 when not.

I plugged it in today (in KWH mode) and plugged my laptop computer's power strip into the unit.

For most use, I prefer the Kill-A-Watt’s “Watt” setting to the “KWH” one – it gives quicker results, and a better sense of a device’s variable power consumption. Also, a short (~ 30 cm) cord works better for me than plugging directly into outlets and power strips.

 

 

where did you get that meter?

I got mine via mail order from smarthome.com – they add US$8 to the cost for shipping and handling in the US, and will ship internationally, through possibly at crazy rates. Searching for the phrase “kill-a-watt” will probably turn up a better merchant for non-US delivery.

[freeztar]

I got a Kill-A-Watt last year, and used it to check various stuff around my house.

 

It was actually a post you made, Craig, that led me to purchase one. :hyper:

 

I also took it with me when I shopped for and eventually bought the below mentioned LCD TV. There are some surprising differences between similar-specification TVs, some drawing more than twice the power of one of the same size and display type.

 

I have no doubt that this single use will find the unit paying for itself very quickly.

 

Interesting measurements from around my house include:

• Sony CFD-E90 “boom box” Radio/Tape/CD player, using AC power
  • Off: < 1 W
    
  • Radio on, low volume: 1 W
    
  • CD on, low volume: 5 W
    
  • Max volume: 9-14 W
    

  ...

 

Awesome, thanks Craig. :eek_big:

 

A typical personal electronics (cellphone, etc) charger draws a few watts when charging, essentially 0 when not.

 

That was one of the items I most wanted to test as I typically leave my cell phone charger plugged in for convenience.

 

For most use, I prefer the Kill-A-Watt’s “Watt” setting to the “KWH” one – it gives quicker results, and a better sense of a device’s variable power consumption. Also, a short (~ 30 cm) cord works better for me than plugging directly into outlets and power strips.

 

Very good advice. I did not consider variable power consumption, but that will be very useful when testing my devices, such as the refrigerator. I also found it a bit akward to read the LCD when plugged directly into the wall, so the extension cord idea seems prudent.

 

I got mine via mail order from Smarthome - Home Automation, X10, Remote Control, Lighting, Wireless Security – they add US$8 to the cost for shipping and handling in the US, and will ship internationally, through possibly at crazy rates. Searching for the phrase “kill-a-watt” will probably turn up a better merchant for non-US delivery.

 

I got mine through ebay for about $23 with shipping. Since the company is based in the US, I would expect high fees for international transportation. But even at $40+ it is well worth it in the long run.

[Ganoderma]

thats one thing i always wonder about is how much power things are using when not turned on, but plugged in. many things like our tv, dvd charges etc all say they use "minimal" power when off, whatever that is. we just unplug everything when we don't use it, the only thing that stays plugged in is the fridge, which is surprisingly only 175 watts....

 

thanks for the link, i know what i am looking for now!

[palmtreepathos]

My mum was complaining about people leaving lights on and how it was costing us more, so I went and calculated how much it would cost to leave all the lights on in the house for the duration of the billing period :( its nothing compared to what the microwave, fridge and computers use.

 

Jay-qu I hope that brought her some peace of mind, it does me...

 

But this one... Imagine this in millions of homes each morning, not to even mention the gazillion Charbucks units!

[*]Mr Coffee 12 cup coffeemaker

• Brewing: 950 W
  
• Warming: average about 200 W, in 15 s bursts of 950 W
  

I had been looking into a "coldbrew system" for coffee and lamented the 30% waste it claims to have, but after seeing these results I am wondering if I added up the cost of electric each day if it would average out?

Cold Brew Coffee with the Toddy Coffee Maker (INeedCoffee.com)

Michael Allen Smith does a great job (with pictures) on how to cold brew coffee with the Toddy System. A definite must-see before you just-do!

Cold Brewed Coffee on the Cheap (INeedCoffee.com)

Malcom McFarren shows a pretty easy (and virtually free) way to build your own cold brew coffee system...for those who want to try this type of coffee before buying a Toddy System.

Simplified Cold Brewing Method (INeedCoffee.com)

Here's how Tom Hawkins puts together his brewing system -- simple and, uh unique.

 

Now add in the cost of nuking water to heat it... :lol:

 

But at least our tunes are not going to break the bank.... THX! :camera:

Interesting measurements from around my house include:

• [*]Sony CFD-E90 “boom box” Radio/Tape/CD player, using AC power

Off: < 1 W

Radio on, low volume: 1 W

CD on, low volume: 5 W

Max volume: 9-14 W

[Ganoderma]

Braun sell coffee makers here that are only 450W hehe.

 

tunes may be cheap. i am curious what our larger car stereos are (i admit to being one of "them" when i was a teenie)

[TheFaithfulStone]

My mum was complaining about people leaving lights on and how it was costing us more, so I went and calculated how much it would cost to leave all the lights on in the house for the duration of the billing period its nothing compared to what the microwave, fridge and computers use.

 

Get yourself a electric kiln and an arc welder. Them's some power hungry devices.

 

Back when I actually USED my kiln, I noticed that it cost me about $25-$50 (depending on the heat) worth of electricity to run a firing.

 

Of course, how does one live without those things?

 

TFS

[CraigD]

I had been looking into a "coldbrew system" for coffee and lamented the 30% waste it claims to have, but after seeing these results I am wondering if I added up the cost of electric each day if it would average out?

Interesting.

 

I learned a long time ago that you can brew tea without heat - just throw some leaf, bagged or lose, into a container of water, don’t bother heating, leave for a few hours, then remove. The resulting iced tea is as good as the quicker, boiling water brewed kind – I’ve done sided-by-side taste tests, and nobody has yet been able to reliable tell the two apart.

 

I didn’t know anyone cold-brewed coffee, though. Coffee’s more complicated than tea, involving lots of oils that get dissolved out of the ground bean by high heat, a processes so sensitive that most people can tell the difference between regular drip-brewed, espresso, and even espresso made by an inferior (ie: little home machine) vs. a superior (ie: big commercial) brewing machine. The visual appearance of the coffee is even effected by the process, especially the “crema” layer on a good cup of espresso.

 

Cold-brewed coffee would, I think, taste very different than ordinary. I note that one of the articles linked, Michael Allen Smith’s ineedcoffe.com article, begins

About 10 years old when I knew far less about coffee than I do today, I attempted my first cold brew coffee. It was a disaster. The coffee was so vile and disgusting I threw it out after a single sip. At the time I assumed it was an inferior brewing method and never gave it another chance.

Even if you use a technique resulting in something good to drink, I suspect it would taste very different than the usual coffee to even a mildly discerning coffee drinker – and, some of them being a picky lot, might not be too popular.

 

 

Now add in the cost of nuking water to heat it... :)

This is considerable.

 

My coffee maker automatically shuts off its heating plate after a couple of hours, so people wanting coffee later in the day usually heat it by the mug in a microwave. My old (1986) 650 W microwave takes about 3 minutes to heat a typical size (~ 2 cup) cup of coffee to the temperature most people like. So nuking one serving of coffee takes about the same amount of energy as making the whole 12-cup (6-8 serving) carafe.

 

Home coffee makers are marvels of heating efficiency – all the ones I’ve seen work by feeding the water from a reservoir past the heater that doubles as the warming plate via a thin copper tube. I suspect you could reheat a single cup of coffee with similar efficiency with a small electric emersion heater in a covered, insulated mug – though you’d have to be careful to rig it so the hot electric heater coil didn’t melt through any plastic part of the mug!

 

Some sort of solar heater would work well for single cups of coffee (in melt-proof mugs!), something like the setup in the video linked from this post from GREENPOWERSCIENCE’s intro thread. :eek:

[Buffy]

When I was a kid my mom got a cold brew coffee "system" that actually was very good (I had just started consuming the stuff at the time, so it became my job to make it!).

 

It had a large white plastic container that held about 3/4 of a gallon of water. On the bottom was a hole with a rubber plug, and there was a half-inch thick round plastic filter on the bottom that looked like the same material that they make "pot-scrubber" plastic sponges out of. All you needed to do was fill it with water and dump a cup or two of ground coffee in it and put it in the refrigerator for a day or so. The plastic container then fit on top of a glass carafe and you'd pull the plug and let it drain which would take about an hour. What you had when you were done was essentially "concentrated coffee" that was much stronger than the heaviest Turkish coffee you've ever had, so if anyone tried to drink that, it would probably cure them of any coffee cravings for life (although it didn't in my case: at least I knew that it was not how coffee was supposed to taste!).

 

You'd mix it with water--probably 2 or 3 to 1: as I say it was *really* strong--and then nuke it in the microwave. I know that made it ecologically wasteful, but as long as you used good coffee, this stuff was *really* good! Supposedly the cold brew keeps it from generating acids or something (hey, I'm *not* a chemist!), so it was a lot less bitter than any other coffee I had.

 

I don't know what happened to these gizmos: they were a fad and I liked it, but for some reason it just did not last...

 

Channeling Mrs. Olsen, :)

Buffy

[palmtreepathos]

There is wildly divergent info on this one... the humble crockpot.

Researching and found this nice list ... crockpot looks very good but I found so many different sizes online I am guessing they used the small one (4/5 qt) on low... it isn't really specified. Freez do you have a crockpot in the test line up?

Typical Appliance Energy Use and Costs

www.clallampud.net/docs/conservation/TypicalApplianceEnergyUseandCost2.pdf

And this chart shows your real friend at the stove is the pressure cooker. I wonder how a pressure cooker would work on a rocket stove? :):eek:

http://photos1.blogger.com/blogger/4189/1379/1600/PressureCooker.jpg

[Boerseun]

Most excellent thread!

 

I'm amazed at the fact that the LCD TV ate more (considerably more) juice than the CRT - I was planning on getting me an LCD because it made sense to me that it'll eat way, waaaay less power than a cathode tube. But there goes that idea. Maybe people should be told about this... :eek:

 

Another point, maybe I can get the LCD, but then drink three or four cups of coffee less per day, and have my lowered coffee consumption offset the higher power usage on the flatscreen?

:)

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:evil:

Nah - coffee rocks. I'll stick to my CRT for a while...