Slashdot Mirror
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."
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/
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.
So register one twitter account per outlet, have them all tweet power usage, then register another twitter account that retweets all the others and then tweets the total usage. Once you start generating that much twitter traffic, CNN will eventually start publishing your tweets on the front page of their website, since their primary news gathering activity these days is reading and re-posting "hot" twitter feeds. Then, you can just log on to cnn.com whenever you want to know your power usage.
Sheesh, do we have to think of everything?
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.
First thing I learned after installing mine: the clothes dryer uses the most electricity by far, and leaving my computers on 24/7 doesn't use as much energy as I thought it did.
I learned the same things. The clothes dryer, stove/oven and dishwasher dominate my power consumption. A microwave is an extremely efficient way to heat food. Computers are small users, even my dual-processor Opteron file server with eight hard drives only draws about 120W. The cool "multi-can" lighting systems in my kitchen, living and family room suck a lot of juice -- each room is about 800W with the lights on. My swamp cooler uses more juice than I thought it did.
One thing I discovered the first day I installed the device was a "phantom" 400W draw that was pretty much always on. By shutting off all the circuit breakers one by one and watching the draw I was able to narrow it down and eventually discover that it was a large vent fan in my attic on a thermostat. It may have been necessary originally, but about five years ago I installed those spinning "hurricane" vents so my attic has good passive cooling -- but with that fan's thermostat set to turn the fan on at about 100 degrees, it was on nearly full-time during the summer. I turned the thermostat up to 120 and I don't think the fan has come on since. Turning it up hasn't appreciably affected the amount of time my swamp cooler runs.
So far, I think I'm saving about $20 per month since installing the TED. It should pay for itself quite handily in a year's time.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
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.
Of course PG&E really wants the capablity to charge us double on the hottest days
Wait, you mean they want the capacity to raise price when demand spikes, so as to help the market forces discourage use when reduced use causes the most benefit to the market, and thus allow them to stretch out their infrastructure allotment and help save the planet?
Shocking, SHOCKING I say! :)