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Real-Time Power Monitoring Options?
tedpearson writes "I've wanted for quite a while to be able to look at my electricity usage in graphed form, both real-time and historical data. There seem to be a number of options for power monitoring in existence: some that hook into Google PowerMeter, others to Microsoft Hohm, and some that are standalone units. I've also seen DIY projects using Arduinos for reading the data and sending it to a computer. But I haven't found anything that is quite what I'm looking for, and I am hoping the Slashdot community can give me some advice. What I'm looking for currently: Some sort of device(s) that a) accurately measures power usage, b) allows me to access the data for storage in a database for my own graphing/analysis purposes, c) will work with MacOS (doesn't require Windows), and d) doesn't cost more than $150 or so. DIY is fine, though I don't understand circuit design, which is keeping me from designing something myself."
I use the Watt's Up Pro, but it's for monitoring a single outlet.
Do you intend to monitor your entire house, or just some devices?
ICQ# : 30269588
"I used to be an idealist, but I got mugged by reality."
And check how fast the dial in the electric meter is spinning.
This is about as cheap as it gets for a DIY project. If I were to give you a quote for a commercial grade version you'd shoot me in the eye. http://www.iobridge.net/projects/category/projects/ http://www.iobridge.net/projects/2009/01/real-time-power-monitoring-system/
Check out the Tweet-a-watt from AdaFruit.
http://www.adafruit.com/index.php?main_page=index&cPath=32&zenid=d5308340ddf8717aa16168614312ae0e
At the meter, you can calculate the power draw. Look for the Kh value on the meter, and count the number of seconds it takes for the disc to make one full rotation. Then, use this formula:
W = Kh / (Seconds / 3600)
to get the power draw in watts.
Of course, this assumes you're still using an old-school spinning-disc meter.
Oh, no! You have walked into the slavering fangs of a lurking grue!
1. Point web cam at power meter.
2. Hack software to read pictures of meter
3. ???
4. Profit !!!
It's a little more expensive that what you want -- $200 rather than $150 -- but other than that, I think it's exactly what you're looking for. The gateway device itself stores sufficient data to allow you to look at short-term detailed usage and long-term trends via its web interface, but if you want more than that, you can set up something to periodically poll the device, downloading detailed, per-second, usage in an XML format. You can then store that data however you like, and mine it however you want.
There may be other solutions out there, and I'm interested to see what others suggest, but I have a TED unit and I couldn't be happier with it. It also uploads to Google PowerMeter.
http://www.theenergydetective.com
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
If all you want is graphing, then Google Power Meter is probably the best way.
That said, there have been a few articles on Hackaday recently concerning methods of interfacing meters with Google's API. I assume that once you submit it, you can get it back out.
Or, if that doesn't do it for you, I'm sure you could adapt one of the projects on Hackaday to your own ends.
http://www.flukso.net/
I don't read your sig. Why are you reading mine?
Take a look at what a monitored PDU costs for a server rack. APC offers them, as do a few other vendors. You're easily looking at $450 per PDU. It will do everything that you want though, including output to SNMP so that you can trap it.
Although designing something like this would be trivial with even a small amount of electronics knowledge, if you have none I'd first go toward one of the turnkey systems earlier commenters have suggested, then be a good nerd and pick up some books on electronics so next time you think of a project like this you'll be well armed.
Free Martian Whores!
1) Wander around house, see if lights, appliances, devices are on/plugged in.
2) Make arbitrary decision about power usage.
3) Turn off/unplug device.
There. Now go play outside.
The Analog Designs ADE7763 is a pretty awesome chip for doing this sort of stuff. Here's the appnote in a pdf, and here's the chip itself. It's quite easily interfaced to an Arduino using SPI. I just laid out a board interfacing this to an ATMEGA1284 for doing power quality monitoring and logging, but it's for an internal project so I can't just hand out the code or layout, but it was a dead simple chip to work with: one crystal and two caps were all it required for support, and if it were interfaced to an Arduino, that could handle all the I/O to a computer or write to an SD card.
Nostalgia's not what it used to be.
See here for a commercial product that exploits this:
http://www.blackanddecker.com/energy/PowerMonitorCompatibility.htm
Check with your power company, especially if you are with a smaller co-op. I write software that does the analysis and historical reporting on modern (aka, "smart", the kind that can phone home with readings on usage, peaks, etc, and all over the powerline itself) meters, and we have all that data like you're describing. More complex systems allow for complete home monitoring, but they do require some specialized devices inside the house.
Here's a link (ok, the first on google I came across on the terms you need) but still, this will get your foot in the door. HTH. http://www.sdge.com/smartmeter/homeAreaNetwork.shtml
If you're in with a bigger firm, sorry charlie, not much to suggest there.
2^3 * 31 * 647
I have an older version of the CurrentCost monitor..
When I get some extra $ together will likely upgrade.
http://www.currentcost.com/
What I'm looking for currently: Some sort of device(s) that a) accurately measures power usage, b) allows me to access the data for storage in a database for my own graphing/analysis purposes, c) will work with MacOS (doesn't require Windows), and d) doesn't cost more than $150 or so.
The old saying, "Cheap, fast, good. Pick two." applies here. You have too many requirements.
No sig for you. YOU GET NO SIG!
See http://www.etherbee.com/products/ECM1240/default.htm
and see what you can output with one of those guys:
http://marc.merlins.org/perso/linuxha/post_2010-08-13_Fine-grained-house-wide-power-monitoring-with-Brultech-ECM1240_-ecmread_py-_with-net-metering-support_-and-graphing-with-cacti.html
There is one caveat: you need windows for the initial setup, although I did it in vmware, maybe it works in wine too, but since then it's been running fine on linux (and it would work just the same on MacOS since it's a python script).
Marc
I use TED. It's right around your price range. It monitors whole-house power usage in real time and has a USB-Serial interface which you can easily suck data out of with Python script. I personally do all the data logging on a Linux box and export it through a web interface.
dont look...just look - make up your mind. also is it possible to not know and have a reference for 'better'?
Windows initially is fine, I just don't want to run Parallels 24/7.
It's beyond your budget, but a friend of mine was "showing" me his egauge...
About $500
+1 for the brultech stuff. I have 4 ECM-1240s and also a TED device. The brultech stuff is much more useful -- though it doesn't agree with the TED device on the actual power consumed by the house. I need to do some experimentation to see which is right...
they don't want a port that makes free power easy. No they want to brake the seal to get at that.
I go to CMU and I did my capstone in Embedded Devices last year. One of the other groups was doing something that was almost exactly what the OP asked for. The project was called Jeules and you can probably still contact the team members to get some more information about it.
Their wiki unfortunately is locked down now, but it used to have the exact parts list and some of the circuit diagrams to build the system.
http://jeules.org/
It would be pretty hard to hack the meter if the pins just output a blip (or change polarity, or any other binary indicator) for every X units of energy are consumed, which is all the information the meter really provides in the first place. That sort of signal could be read directly by a serial port if you really didn't want to build an interface, or converted to a real digital signal with a pretty trivial circuit.
That being said, it's not that difficult to build a circuit that optically reads the LCD "wheel" indicator and blips when it goes around.
I use a branch current monitor from PowerLogic (BCM42) coupled with a Barionet-50 to perform monitoring of every circuit in the house simultaneously. Some details can be found here:
http://blog.insidesystems.net/modbusrtu-via-tcp-serial-gateway-with-ruby
The kinds of analysis you can perform with this are tons of fun. For instance, how much does that desuperheater in my geothermal unit really help the water heater? Has a lightbulb in one of my floodlights gone out? Did somebody leave the refrigerator door open? Has the water softener stuck again causing the well pump to work overtime? This approach lets you monitor WAY more than just consumption.
The DIY rig at http://openenegymonitor.org/ is fairly straightforward, even if you're not that technically inclined....
Otherwise I'd just echo the suggestion to suck it up for the extra $50 and get the Ted 5000
My recent time-waster is finding a way to make all these different gadgets able to talk to all the various websites ...
What you want is a Zigbee enabled monitor in the home and a smart meter outside the home. The two can then communicate with each other. This shows entire home usage though, not just for a single device. Zigbee Alliance and WiFi Alliance are cooperating, so I presume some sort geek friendly device exists.
In conjunction with getting solar power at home, I've also set up real time usage monitoring.
I've had a stand alone power monitor for a while (our state Government offered them + a bunch of CFLs and other stuff for $50). However it doesn't have any PC connectivity. One day I was looking in the meter box, and I realised that the sensor was just a clamp meter around the input wires.
I already had a clamp current meter attachment for my multimeter (which also has RS232 out), so I put the clamp around the same incomming wires, connected it to my multimeter and then to my PC (via an RS232 -> USB cable). From there I have some scripts to take readings and enter them into a database as well as a web interface for output. Fortunately for me, the meter box is just outside of the room where the PCs are, so it was easy to wire up.
I actually did this setup in a number of stages. Initially, I used some software for my multimeter to plot / save to text file the raw (amperage ) data. I then started batch importing it into the database and calculating wattages etc from there. Now it all happens automatically. Readings are taken at 1 minute intervals.
Even though I already had all the parts, they cost well under your budget. From memory their original costs were:
* clamp meter attachment (Digitek QM1565) $25 (see http://www.jaycar.com.au/productResults.asp?keywords=QM1565&keyform=KEYWORD&SUBMIT.x=0&SUBMIT.y=0)
* multimeter with RS232 (Digitek QM1538) $50 (NB. this model is no longer available, don't know what an equivalent would be)
* RS232 -> USB $6 (from eBay)
Now I live in Australia, so your meter box setup may be different to ours. In mine, the meter and circuit breakers etc are mounted on a board in the box. This board has hinges on one side, so you can swing it out to get behind it. That's where the wires are that you need to put the clamp around. Obviously you want to be very careful back there, but there *shouldn't* be any bare wires etc. If in doubt, you could get an electrician to do this for you.
I've put a sample of our median usage and production on Imageshack http://img31.imageshack.us/i/electricityusageandprod.png/
Here is the usage and production for a single day http://img163.imageshack.us/i/usageprodction20100915.png/
Having this type of data is great for tracking down where your usage is going.
Ever stop to think
They'll call you about once a day, and you divide what they demand right now by your cost per kilowatt/hour.
Orwell: "In a Time of Universal Deceit, telling the Truth is a Revolutionary Act"
PG&E was very close to rolling out the capability for nearly everyone in California to look at their power usage in near-real time online, but public hysteria over the "RF" generated by smart meters has halted rollout in many locations.
The recent gas line explosion really has called out the pitchfork and torches types, so I except most other locations in the US to have this a lot sooner than California.
Of course PG&E really wants the capablity to charge us double on the hottest days, but they would also like to be able to offer reduced rates if you charge an electric vehicle at night. Right now, if you have an EV you have to put in on a separate meter to get cheaper nighttime electricity for it.
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
I had that desire too, but my electronics skills were up to an overkill DIY solution...
http://www.delorie.com/electronics/powermeter/
I record watt-seconds for each of 64 circuits once per second to a linux server.
I did this exact thing not long ago: http://www.streamlinemechatronics.com/power/index.php Schematics and source are already posted. Total project cost was $150.
I have been using a custom Phidgets for the past couple years to monitor electrical usage in my house. I have one of these http://www.phidgets.com/products.php?category=8&product_id=3503 to monitor each branch circuit in my electrical panel. I then have http://www.phidgets.com/products.php?category=0&product_id=1018 this connected to my main pc to do all the data logging. I have written a custom c++ application to dump the raw data into a mysql database and then i have PHP to query data and datasets for reporting. This comes close to your budget if you only need to monitor a couple circuits. If you monitor all 26 of your branch circuits in your house, then this can become fairly expensive compared to your budget however all the other electrical monitoring agents you will find will be several THOUSAND dollars for some "professional enterprise data center solution" to do the same amount of logging and same features which the phidgets can do for 1/10 the price. Instead of spending $10,000 you spend maybe $500 for the same or better features and compatibility.
Plenty of solutions that will work if you are willing to poll serial links for mod bus registers at a reasonable cost.
1. buy a kill a watt. 2. hack it open (physically). 3. open your breaker box. 4. disconnect the wires from the hot side of the box to your main breaker. 5. connect the wires you just unhooked to the plug side of the kill a watt. 6. connect the socket side of the kill a watt to your main. 7. repeat with the other wires. 8. you have just setup a whole house power monitor. all the KAW is, is a meter, just put it in higher upstream. you guys are over thinking this.
What's the cheapest Zigbee/controller/sensor that I could cook up to do this? Then I could write Linux apps to manage the data from the Zigbee network.
--
make install -not war
The big picture, the large scale energy consumption events in our lives, we only know to one or two decimal places. The whole research and decision making process, for a large group of Slashdot commentators like you and me, boils down to find an energy waste and fix it.
See:
http://www.withouthotair.com/ ; An outstanding accomplishment at viewing the energy situation using consistent units and definitions.
Because many energy usage problems require outside information, my experience is a pad of paper and careful collection of outside information is a big part of reducing energy usage. High quality local data (just a few points are needed) and outside data (got by copying it onto a pad of paper) are needed for energy analysis. I use Gnumeric for my spreadsheet. It helps to save results on the computer and on paper printouts as a specific energy usage problem is addressed.
For the last go round at measuring my home energy instances, I used a Kill-A-Watt meter (Frys.com in Northern California occasionally puts it on sale for under $20.). Note, the Kill-A-Watt will not measure a 1200 watt microwave oven (too much current) and it will not measure a 220 volt electric water heater.
While the Kill-A-Watt told me my refrigerator was an energy hog, it was not a whole lot of help at determining precisely what was wrong with the refrigerator that made it an energy hog. I did a couple of tests exploring various ideas: bad insulation, too many door opening events, weak door gasket magnets, dirty condenser coils, and an unfairly optimistic energy usage rating system. I eventually bought a new refrigerator. That key purchase required going to the store before my wife, copying all the energy usage and model info and price, and then shopping with the wife and a spreadsheet in hand to balance the wife's desire for style and design with energy usage and price issues solved in advance for many of the choices at hand.
The end result was a new refrigerator that has a 1.56 year payoff period.
One of the problems I am looking at now is "Does the gasoline burned by my wife's commute and my commute exceed the amount of energy consumed by the whole house?" It is another case of some outside numbers, some inside numbers and the outcome will be at best a 2 decimal place result. And what will I do when I find the result?
Oh sure, let me wire that bastard into the main feed outside.
Oh wait.
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
For 220V :
I also installed this at work on 3-phase.
Cost:
This is because most CTs (current transformers) are not calibrated properly by the device they're connected to. I used 3 different CTs on the same load in my setup and made sure they were reading about the same. With the ECM1240, you can adjust offsets to make the CT readings "just right" should they be off a bit when you get them.
I worked with the owner, and he does care about getting as correct values as possible and made his device very tweakable.
Marc
In France most recent powermeters have an output called "teleinfo" which we can have activated, basically a kind of serial link (output only), repeatedly giving lost of parameters like instant watts, actual indexes in watt.hours and more. This kind of meter can be found second hand on ebay I think, and it is just a matter of demodulating the (well documented) 'teleinfo' output. What I did with this output, is to log the status every minute into a postgresql database (since 07/2008 now) and then it is easy to graph the data. You can see how often and how long the fridge is working etc... As an example of the result: http://2oo4.free.fr/teleinfo.jpg (in French, but you can figure out with the units). Be sure to match the characteristics of your power network (we have 230 volts/50Hz here) Kind Regards, Benoît.
The newer CurrentCost meters are not only inexpensive, but also provide a serial interface (over USB).
A friend of mine has created py-power-cost to extract this data into a DB and generate reports/graphs viewable via a web app.
Wes
Check http://ekmmetering.com./ They sell simple metering units that can either meter small (up to 30 amp, I think) circuits directly, or any size circuit using external current sensor rings. You can chain together a number of meters with simple 2-wire serial connections and attach them to a net-connected controller. The controller can be read from anywhere with a simple TCP socket call or they provide a free app that does it. The app runs on Windows, Mac or Linux. I plan to use their stuff for a networked submetering system for the co-op I live in, to allow us to consolidate down from 30 utility meters (which cost $14 per month just to be hooked up) down to 4 meters. This will also allow us to share and net-meter a large solar array we are developing.
I work for a company that provides a meter, and logging service. For a single phase house load we would use an EDMI mark 10. You'll need an electrician to install it, but it has all the logging abilities and is quite accurate (+-.05%). Alternatively you can get a multimeter for your computer and hook it up to a CT (current transformer) which you clip around the main line coming into the house (no bare contacts no electrician) the current in the wire induces a current in the ct; (a lot of multimeter cards have a logging ability) and if you log those currents at intervals, and multiply those by the fairly constant voltage (240/110V). You’ll have watts over time. You can tell a lot about a person when you know when and how much electricity they use (for example when they use the washing machine, when they get up, when they have a roast dinner). I understand this story is from a few days ago, but hope it still helps.
Rocket Surgeon.
checkout the Wattnode. This device does a lot for the money. There are many different configuration options, and plenty of technical info on their site. http://www.ccontrolsys.com/products/pulse_output.html datasheet: http://www.ccontrolsys.com/downloads/Data_Sheet_WNB_Pulse.pdf checkout the application notes as well: http://www.ccontrolsys.com/support/app_notes.html
This is the solution you are looking for: http://www.wattvision.com/ This is actually being developed by a friend of mine. Let me know if you need any additional details.
My particular meter does not have this feature. It has the 2 LED (more likely 1 LED, 1 photo detector) interface, but it does not work the way most do. I was considering getting one of those Black & Decker power monitor devices, but my meter is specifically listed as not compatible because the interface doesn't operate the same way.
As the GP said, it may be possible to make a device to read the LCD "wheel" but not nearly as easily as a simple blinking light would be. For now I'm just relying on the power company's (crummy) website to get 2 days-delayed data.
Personally I think the power companies are against the consumers having real-time in-home display. While they always push conservation in order to keep their PR campaigns in full force, we have to remember where they make their money. They don't want us to see a blinking red light on our wall to remind us that there are too many lights left on in the house, or that Jr. forgot to turn his TV off when he went to sleep. They push the EnergyStar appliances and tell us to swap out our old water heaters and refrigerators, "which will save $20 a year in energy expenses! OMG!!!" What they don't want us to do is have an easy way to find the little things we are leaving on unnecessarily which could easily shave $20 or more *per month* off of an average geek's bill.
What I have been considering is a full setup from Brultech. http://www.etherbee.com/BrultechSampleSite/store/category.php?id_category=15 I haven't taken the chance to go figure out which model would fully cover my panel (I need to go see how many circuits I have and what size of main supply I have) but I think the $400 range models would be enough. With an average power bill of $115, if I could see a 20% savings by better managing my power usage it would pay for itself in a year and a half.
In the end, I think the power companies prefer to have us looking at "the big picture" which tends to bury the details. Since "the devil is in the details" they are providing us with just enough information to make the majority of people think they are doing everything they can to help.