Real-Time Power Monitoring Options? 172
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."
Re:Reading the meter (Score:3, Interesting)
Why are you all assuming there is a turning disc in the meter? I haven't had one in mine for many years. There is only a digital readout with FULL KW/h and no current load reading at all. It is completely useless for real-time monitoring. Thanks for the "improved" meter, Virginia Dominion Power!
You might be surprised ... (Score:4, Interesting)
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 [sdge.com]
If you're in with a bigger firm, sorry charlie, not much to suggest there.
Re:Reading the meter (Score:4, Interesting)
The digital meters used in the Idaho Power area anyway has a scrolling line on the bottom of the digital display. This represents the old turning wheel and uses in fact the same calculations.
http://efundies.com/electricity/how_to_read_power_meter.htm [efundies.com]
Our power meters use a slightly different digital method, it has a bar that "fills up" at the bottom, and it is measured from the moment it resets to the next reset as the equivalent to one wheel revolution.
Your power meter should have a way to see current usage, give your utility a call if you can't figure it out, and if there is in fact no way to read it, I'd get in touch with the public utilities commission and see if it is a requirement.
Overkill DIY solution... (Score:5, Interesting)
I had that desire too, but my electronics skills were up to an overkill DIY solution...
http://www.delorie.com/electronics/powermeter/ [delorie.com]
I record watt-seconds for each of 64 circuits once per second to a linux server.