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Measuring the Energy You Use?
centdollarman asks: "Everyone keeps talking about how energy is being wasted here and there. Energy bills keep soaring for me, and now I'm back to paper and pencil: just taking notice of the power meter values. Mine is nice, as it has a cute LED that blinks at 1/1000 of a KWh. However, there has to be a better way to do this, and I've started searching the web for someway to count my usage, automatically. Of course, this is easier said than done. It would also be nice to have some way to (cheaply!) measure the power consumption of a single device."
So, for the energy conscious among us: how are you measuring the power you use?
Don't you have meters anywhere you could keep an eye on?
Extensive tracking on a per device basis is probably going to use up energy itself, so I'm really not sure if that bit will achieve too much.
"I Know You Are But What Am I?"
blinks at 1/1000 of a kWh
In these parts, we call that a Watt-hour. What are you, some kind of Canadian?
I use a periodic system to update me of my power usage. It comes in the form of a letter from the power company and it tells me how much power I've used as well as the cost for usage for that month. It's really convenient, but I am not really interested in the dirty details of where all that usage is going.
I suppose if you're really interested, you could try turning off your A/C or electric heating. Kill the water heater except immediately before showering. Turn off lights you're not using. Turn off any computers that are unessential. And CLOSE THE GODDAMNED DOOR. WE'RE NOT COOLING THE WHOLE OUTSIDE!
http://www.thinkgeek.com/gadgets/electronic/7657/
The Datacentre we have our kit in has these small LED based ammeters on each of the power strips.
E nergy_Devices.html?gclid=CJ2il5S3r4cCFTpsEAod3n1L- Q8 3,1324,1328&mid=4084
:)
Very handy for figuring out where our power budget is going.
Google provides the following in quick order
http://www.energyoptimizersdirect.co.uk/acatalog/
http://www.blackbox.com/Catalog/Detail.aspx?cid=1
Enjoy
Help! help!, the termites are eating my DRAM!!!
1. Switch off your computer when you're not using it. (unless you're running a really important server or something. SETI@home does not count.
2. Switch off the lights when you leave a room.
3. The TV doesn't need to run all the time.
Every little bit helps. If you're already doing stuff like this & you're bills are still soaring, then you can try the measurement parts.
I can explain it for you, but I can't understand it for you.
kill a wattl =en&btnG=Search+Froogle
http://froogle.google.com/froogle?q=kill-a-watt&h
every day http://en.wikipedia.org/wiki/Special:Random
Homebrew is the way, particularly if you are interested in electronics. I have a similar meter - this is what I did:
Get a photo-diode, and make it face the blinking watt-hour LED. Use a comparator to convert the state of the LED to a logic signal. Then connect that logic signal to your computer. I did this by having the signal trigger an oscillator which sends an audio signal to my computer's sound card when the LED is on. There are other ways to sample an external signal (e.g. parallel port) but this was the easiest way to arrange things. A program on the computer is constantly listening to the line input: it counts the interval between pulses and calculates the power consumption from that.
My exercise bike automatically displays the energy that I use. I usually quote it in megajoules since it sounds more impressive that way.
I agree with some other comments about conserving energy as a good way for going and stopping your bills from going up... as for a way of measuring you can see that kill-a-watt device some people have shown, it seems like a good idea. One issue is that it doesn't really tell you how much power things like lights and your oven use though (because they don't have standard plugs - at least not here).
The only way I can think of doing that, although it would be a hastle, would be to switch off all items in your house and verify that with your little light not blinking, then switch your oven on and time how long it takes you to use a Watt/hour. Then switch that off and see about the lights you would normally have one. This would give you some ideas on how much these things use. As a way of reducing the amount of power that they use you could get energy efficient bulbs (they cost more innitially but less in the long term) and if you need to replace your oven you can look for the most energy efficient one you can find (and if gas or electric is cheaper in your area angle your purchase towards that).
There are also good savings to be made by changing your fridge/freezer and your washing machine to something more efficient (If you live in England we already have a rating service for these, buy only A rated things and you'll save - if not then you'll have to do some investigating on your own)
*''I can't believe it's not a hyperlink.''
It's easy to say "switch everything unnecessary off". ...and so on. I switch all the huge energy hogs off, but there are many dozens of small devices which pull 5, 10 watts of energy, 24/7 and it really adds up. A quick and easy way to measure actual power usage of a device would be really nice.
Sure I do switch off the obvious things. Then still my bill is high. Then I check: The monitor (22" CRT) is rated at 40 Watt in standby mode. The ethernet switch is pretty hot. I have no idea how much the laser printer needs in stand-by, but likely not all that little. All these toys plugged into the USB hub, do they remain off when I power off the computer? The BNC ethernet wire was shocking me with electricity. I grounded it, but how much does leak to ground that way? The grounding sparks a little when disconnected. If I leave the battery charger plugged in, it's warm even if it's not charging any batteries.
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
Now that this is on topic, let me ask:
Where can I buy an inexpensive Watt meter for use with European sockets? Preferably in the Netherlands, but any place that will ship to the Netherlands is fine, too.
Please correct me if I got my facts wrong.
I had about 1-2 bulbs breaking a year.
About 4-5 years ago, i started replacing the broken ones with fluorescent bulbs.
Not a single of those ever died.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
That was known as a watt/hour for about a billion nanocenturies!
Reminds me of old jokes about everyday distances measured in attoparsecs and the like, some were really funny. Anyone got some links?
For electric powered, of course. There's a nice little device called Watt's Up that you hook between your motor controller and battery and displays about everything you need to know to optimize your setup. I did a short review, becaue I plan to create a competition based on how little energy you spend on your model flying. Should be interesting, fun and educational.
Get two cheap AVO-knockoffs, one of which must have an AC current range. Measure the voltage across the appliance and the current flowing through it. (Note; you will inevitably be measuring either the current drawn by the voltmeter or the voltage drop due to the ammeter. Neither matters much with modern instruments.) Multiply the current by the voltage to get the power in watts, divide by 1000 to get kW, and multiply this by the time in hours to get Units. (1 Unit == 1 kWh == 3.6MJ). For geek points, interface all this lot to a computer. Since you'll be dealing with mains, your circuit will need to be optically isolated. I recommend to build the whole measuring circuit "live", and use an ADC with a synchronous serial output. This way you only need clock and MUX drive (voltage / current selection) in, and data out; you can use just one dual and one single opto-isolator on the printer port. If you don't understand the above, don't try it.
I have also seen standalone plug-in power analysers with a pass-through socket and an LCD showing, in turn as you press a button, the voltage, frequency, current, power, time and energy consumption. They aren't as accurate as a real laboratory instrument, but you get what you pay for.
Je fume. Tu fumes. Nous fûmes!
1800 watt (~15 amp) maximum; LCD display; ampere, watt & power-factor modes; built-in tracking totals; possible PC integration: http://www.doubleed.com/
A lot of times energy companys just make an estimation of that you bill SHOULD be. If it seems unually high you can request them to come and get an actual reading on your meter. If you're meter still reads high then you should start checking the things that the others have posted about. Not only may this identify that there IS a problem but could also save you some coin on the bill. At least that's how it works in the private sector.
Ask not what you can do for your country. Ask what your country did to you
Of course, a 50 pound battery isn't very portable, and I wouldn't drag it around to the refrigerator, dishwasher, lamp, or garage. But I'm mostly interested in the computer's draw anyway, since it's one of the biggest power drains in my house.
John
Turning off your lights and computers really won't do that much. ~50% of one's home energy usage is for HVAC. About 20% tends to be for hot water. If your fridge is more than say 15 years old, it probably accounts for another 10% of usage. Lights are usually ~10%, and computers, electronics etc are usually less than 10% of one's usage.
What we really need is a display on the wall, next to the thermostat, that looks like the fuel economy guage on the Prius. On the right is the current consumption, on the left is a bar chart showing past consumption averaged over 5 minute periods. It makes driving the prius like a video game where getting the highest economy is the goal. I'd think if we had such a display, you'd keep track of your consumption, and you'd know if you were drawing more power than you should be for any given time; like leaving a light on in the basement.
How can we expect people to conserve without any easy-to-see meausrement of consumption.
-Geoff
Check out TrailRegistry.com, my hiking site, Maps, altitude pr
To measure cheaply on a single devices, get a used mechanical power meter.
For automation, it getst expensive. Basically you need a power meter with some sort of interface. I expect this to be in the $300 plus price class, since it is professional equipment and not mass-market.
Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
See if you can get your power company to install an electrical meter with radio-read capabilities. I'm more familiar with water meters, which come in at least two flavours - radio read that sends a signal back in response to a message from the meter reader (using a hand-held meter reading "gun"), and a unit which sends a small packet of meter information every 1-5 minutes. Some info on Wikipedia about automatic meter reading (AMR).
Then all you have to do is possibly reverse engineer their protocol, or at least connect a radio transceiver to your PC and program your own meter reading software.
Of course, I think you are worrying too much about having instantaneous data. I would approach your power usage as an environmental auditing problem. Your power use is more a result of your long term habits and the devices you use. Does it really matter whether your computer and 22" CRT use 600 or 800 watts combined when you know that a Mac mini and LCD would probably use half of that or less? Do you really need to leave your computer on overnight? Does it matter that you have energy saving light bulbs if you leave every light in the house on all day? Is your refrigerator more than 10 years old? Are your appliances energy star rated? Do you hang your clothes to dry outside whenever you can, or do you use an electric clothes dryer?
For power consumption, average long term values are more going to be more important than real-time numbers. By changing your habits and the way you use energy, and tracking the changes and the effects on power consumption as you do that, you'll have more of an impact, that will last far longer than your current fascination with your power usage. You might want to measure the total energy used in a day or a week by various appliances such as your fridge or your TV, in order to determine whether it makes sense to replace them with more energy-efficient models. Beyond that, electrical powered devices use power, just like cars use gasoline. If you choose to use them, you're going to have to pay.
Slashdot - the place where you can look like a genius by restating the obvious
Depending on where you live, you might be able to borrow an energy meter for free. For example, in Ottawa (Canada), the public library system has about 200 Kill-A-Watt meters available to borrow for three weeks, just like a book (search for "kill-a-watt").
Check out the standby power consumption. I was surprised by my powered subwoofer taking 8 watts when it's "off". Along with the TV (6 watts), receiver (6 watts), and DVD player (4 watts), that was enough waste to make me turn them off at the power strip.
This seems pretty obvious but I constantly see people leaving stuff turned on when they're not using it.
Leaving the TV set on when you're not watching, leaving the light on when you're not in the room, leaving the water running while you brush your teeth, you name it, wate of energy and natural resources seems to flow in some people's bloodstream!
And those poor bastards who use that lame-excuse-for-an-instant-messaging-program called MSN Messenger have a special way of wasting energy: leaving their computers on all the time so they can have their nicknames online. Why? Want to receive messages that are sent to you while you're not logged in? Use ICQ. I know the new version of MSN Messenger (or Windows Live Messenger, or whatever) stores messages for you while you're away but ICQ has always done it. Or even better, why not use e-mail, which serves exactly that purpose - sending messages that can be read at a later time?
For my house, A/C is by far the biggest chomper of energy. During the summer months my electric bill gets as high as $270, and during the winter it gets as low as $70. Not only that, but on hot (97 degrees f) days my upstairs never gets cooler than about 78f.
It's a fairly new house, so I can't simply replace the upstairs unit, but I think it's clear that they didn't install a large enough one. What can I do? Put another powered roof ventilator in? Add more insulation in the attic? Put a radiant barrier on the underside of my roof?
This website helps to answer these questions. It provides some analysis of the different scenarios. Dunno if the analysis is accurate or not...
Seasonic makes a device called the power angel (http://www.seasonicusa.com/power_angel.htm). You plug a device into it and it measures the power that it's consuming, and a few other quantities. I've found it to be very useful.
I use a Centameter. The measuring device is installed in the meter box. You carry around a wireless LCD display that shows power usage in either kWh or A. I managed to reduce my house standby power usage from 0.44kWh to 0.21kWh because I discovered some appliances with atrocious standby usage; they're now turned off when not in use. That's going to save me $282 per year - I pay 14c/kWh - so the meter has paid for itself already.
http://www.ambientdevices.com/cat/Ambient_energyPI F.pdf
Gasoline produces 32 megajoule/litre, 1 kWh is equivalent to 3.6 megajoule so 1 litre of gas ~= 10kWh. 1 kwH of electricity ranges from 5c to 25c depending where you are.
For Canada:
1 MJ of oil energy ~ $0.04
1 MJ of electric energy ~ $0.03
How much is a MJ of of electric or oil energy where you live?
http://www.thinkgeek.com/
Search for Kill-A-Watt.
It will track the consumption of a device (or even a breakout block with 4 sockets, with this thing in the wall) over a period of time.
The alternative is replace the power distribution box in your house so you can monitor each room's usage.
Lots of devices, even when turned off, draw power in a standby state. The only way to find out which ones do that and how much they draw is to use a killawatt or something similar.
I'm pretty anal about energy conservation. I have nearly all of my powered devices plugged into strips. I frequently not only turn off the device when I'm done using it, but also the strip itself when I know I'm not using any of the devices on the strip. This prevents slow current usage by devices even in their standby state. Any devices that aren't able to maintain their settings when the lose power (and don't have some form of built in battery back-up, like my alarm clock) get plugged directly in to the wall.
Long signatures suck.
If you do a cost-benefits analysis on replacing appliances with more energy-efficient models, you'll find that it's usually not worth it, unless the old appliance is already at the end of their life.
Say you have a fridge that cost $800 to buy, and you've had it for 10 years. If you think it will last another 10 years (not unlikely), then by throwing it out now, you're throwing out $400 worth of value (using a gross simplification). How many kWh would you have to save over the next 10 years to add up to that $400? And if you're looking at just the energy consumption of the device, from a purely environmental standpoint, throwing out a fridge only halfway through its life is throwing away half of the energy used in its production. This is not an inconsequential amount.
While I heartily agree with replacing dead appliances with more energy-efficient ones, I do recommend some deeper analysis before any functioning ones are thrown out to make room for newer things.
It may look like I'm doing nothing, but I'm actively waiting for my problems to go away.
--Scott Adams
with the subsequent warmer weather, less energy use will follow.
2nd scenario: Use less energy this winter and the greenhouse gas effect drops;
with the subsequent colder weather, more energy use will follow.
recent slashdot link: http://www.fastcompany.com/magazine/108/open_light bulbs.html
I knew they were more efficient, but the numbers are pretty staggering.
CFL's are the next wave... until LED's become cost effective for mojor lighting tasks
Here is a site that has made me excited about monitoring the power usage in my home:
http://www.kondra.com/circuit/circuit.html
This might help: The Clapper
I clipped AC current sensors onto my house's main lines, and used an old serial-port A/D converter to sample twice a second for a couple weeks. You can tell a lot just from the gross current draw, because most of the big power users have recognizable fingerprints: refrigerators have startup transients, the microwave oven has no startup transient and a precise duty cycle, the electric range (at 220V) draws from both sides simultaneously, et cetera.n tMeasure/index.html.
Details at http://webpages.charter.net/curryfans/peter/Curre
My first thought was that you wanted to measure how much energy your body used. Ooops.
(just kidding) All you have to do is hook up a large induction motor right after your meter. Then connect that shaft to a dynamo rated for the max consumption of your house, plus a safety factor - for a typical US house a 7500W generator should do fine. You still get to use all the energy you were using before, but with a power factor of about 0.2, they bill you a LOT less! (/just kidding)
But really - has anyone noticed that 'they' are phasing out low-watt appliances in favor of higher consumtion ones: 15 years ago I had a 900W hair dryer. When that died, I couldn't find anything under 1200W. When -that- one died last year, I couldn't find anything less than 1850W. Seems just like the W98 -> W2K -> XP expandable bloatware effect.
My room can go up to 90F degrees in the hot days. Central unit doesn't work. I heard having those mini-AC for the room works. However, I have no room for it and I am worried about its power usage for the room (can cause power breakages?).
Ant(Dude) @ Quality Foraged Links (AQFL.net) & The Ant Farm (antfarm.ma.cx / antfarm.home.dhs.org).
I too wanted to get a handle on my power usage. I found this site that details how to build a complete power meter and interface it to your computer. Let the slashdot effect begin.
http://www.edcheung.com/automa/power.htm
machinator omnis sine licentia
How about installing simple power meters in your breaker panel, on each circuit? That way you could monitor each room in the house and in many cases each device (such as big appliances) separately. I'm surprised no one sells such a kit.
Off the top of my head, it would involve adding a small coil of wire around the hot wire of each circuit, and reading those with some A/D's (4 kHz should be sufficient). Tap into one of the hot wires to measure voltage, again using an A/D and probably a step-down transformer. Use a small embeded controller to read all the A/D's and do the correct math (average(A(t) * V(t)) and make the data available on a LAN. I'll bet the whole thing would cost under $100. You'd have a detailed break down of your monthly power bill.
If you had bothered to read the question, you would have known that the knowledge seeker was already watching his meter.
Consuption of power wouldn't be an issue, since the question was not about *tracking* usage, but rather *measuring* usage. Any difference caused by the measurement device could easily be calculated by running it on a known power consumer (light bulb, etc).
Here is a link to a previous slashdot article that shows how to monitor every circuit in your house.
Home power monitoring hack
has anyone noticed that 'they' are phasing out low-watt appliances in favor of higher consumtion ones
I call that Americanitis, If enough is good, too much is better!
Apocalypse Cancelled, Sorry, No Ticket Refunds
I love the centameter.....www.cenergies.com in the US.
Turning them on and off reduces life. I leave mine on 24x7 and since 1992 have only needed to replace about 3x. The last set was purchased in 2001. I remember because I hired the same guy to install a ceiling fan in my office that year as wired my garage the year before. I have not replaced the blubs yet. So that is 5 years on a set of three (3) bulbs which draw 13 watts each.
I happen to recall I got close to 10 years from at least one of the previous bulbs. I had to replace both (I was using 2 back then) adn it was about 2-3 years before I replaced the fixture.
Keeping track of things that last almost a decade is hard.
I did something similar for my 2-phase 120V supply:
Found some loop current sensors (3 times $25 each) http://www.ampsense.com/
Found a 240V 10:1 transformer/wall wart for voltage monitoring ($5 surplus store).
Hooked them up to a Labjack USB (about $100) http://www.labjack.com/
A few pages of C code, cron jobs and Gnuplot et voila!
http://dfsmith.net/cap
good question! It has been solved. the answer.....TED www.theenergydetective.com
I read about a great solution some time ago, but I couldn't remember where. It might have been here, it might have been digg. Regardless, I found the link with the google query "power monitoring system"
http://www.kondra.com/circuit/circuit.html
It's very involved and detailed and it looks like anyone who tried to replicate the system would have to spend quite a bit of money, but then you'd have access to all of the data you could ever want about your power consumption.
I'll include the last page of the linked site here, just for your own edification:
Wisdom
So what did I learn from this project that I can pass on to other folks crazy enough to try this?
* DON'T MESS WITH HOUSE WIRING UNLESS YOU KNOW WHAT YOU'RE DOING!
* While my software was sort of overkill, I've got to say that having high resolution historical data for every circuit in my house has been very informative.
* Keep in mind that when it comes to friends and family, 'informative' is a relative term. Although you might find it very 'informative' to know that your wife left the lights on in the living room three out of four nights last week, she will probably not think so. I've found it better to save my geek points for things like "honey, don't you think we should have a raid server?"
* Just because you know how your electric bill breaks down now, don't expect to see any great savings. In my case most of the power went to my computer stuff. I will say that as a result I've rotated out some older dual cpu servers for lower power single cpu boxes and have tried to consolidate server functionality quite a bit.
* If you know modbus and you don't need something quite as sophisticated as what I put together, the Veris board has a bunch of features built in such as alarm levels, etc. For a simple home system, this can make the software part of things quite a bit easier.
Reinvent the wheel only at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
I got one of these http://www.centameter.co.nz/save-power-new-zealand /centameter-technical-info.php It is great to be able to look and see your actual power consumption at a glance. I find it really makes me think about any extra lights or appliances that are on.
We have not inherited the earth from our parents. We have borrowed it from our children.
is there a cheap network enabled (snmp) meter? maybe that can help us by allowing us to pool the power consumption with historical charts so we can track our usage. being able to check on the watts usaged at any given moment is good and by turning on/off devices, we can measure its actual consumption (especially the standby and typical ones.)
Live your life each day as if it was your last.
This is a solution I tried out for measuring the power consumption of a single device, and was a little surprised that it actually worked (although it's not automatic, so this doesn't really help the OP):
Last year I finally bought a new computer, but decided to keep the old one as a server. Feeling a bit guilty about having it constantly on only for those rare occasions when I actually needed it, I decided to start running Folding@home on it. But then I wondered if I wouldn't actually be using up even more energy by virtue of actually having something running, rather than just having the PC idle. So I wanted to compare the power usage of (a) having the computer off, (b) on but idle, and (c) running Folding@home.
So this is what I did: during a week when I was home alone (everyone else was on vacation), every morning when I left the house I wrote down the electric meter reading, and then wrote it down again when I got home. During the first few days I kept the PC off, to get a base reading (the fridge, all those appliances which may be on standby, etc.), and then for the next couple of days took readings with the computer on and running Folding@home.
A little surprisingly, the distinction between the power consumption when the computer was on or off actually showed up very clearly in the data, and although I had only a few data points (two of the computer on, three off), the difference between the two cases was much greater than the variance within each case.
To sum this up, using a statistical approach can actually help you measure the power consumption of a single device using your electric meter, without unplugging everything in the house.
[Just for those of you who are interested, the power consumption of this PC whicle running folding@home was 0.035 kWh. Unfortunately, the rest of the family came back from vacation before I had a chance to make measurements comparing the idle Pc to the running one, so I haven't yet resolved my original question...
This is what the raw data looked like (the readings are in kWh), straight from my palm:
72409.7 2/6/05 7:07 (Thu comp off)
72412.4 2/6/05 21:30
72416.0 3/6/05 9:39 (weekend)
72444.9 5/6/05 7:56 (Sun comp off)
72446.6 5/6/05 17:13
72451.2 6/6/05 9:08 (Mon Comp on, FAH running)
72453.5 6/6/05 19:19
72458.3 7/6/05 7:21 (Tue Comp on, FAH running)
72461.4 7/6/05 21:18
72465.0 8/6/05 7:11 (Wed Comp off)
72466.1 8/6/05 12:51
]
Buy a cheap amp meter and learn how to use it?
Or even better yet how about that thing on the side of your house that has the little shiny spinning disk.. Its not from mars, it tells you total energy useage for your place, both in real time and elapsed.. Its how you get billed each month. Its called a watt-meter, go figure.
---- Booth was a patriot ----
K = kelvin, not kilo.