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Real-Time Power Monitoring Options?

Soulskill posted more than 4 years ago | from the preferably-free-of-charge dept.

Power 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."

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Watt's Up Pro (2, Insightful)

Robbat2 (148889) | more than 4 years ago | (#33692014)

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?

Go round the side of your house (2, Funny)

2.7182 (819680) | more than 4 years ago | (#33692052)

And check how fast the dial in the electric meter is spinning.

Re:Go round the side of your house (0)

adamdoyle (1665063) | more than 4 years ago | (#33692144)

+1... if you're too lazy to walk a few feet outside and read your meter, then you're definitely too dependent on electricity.

Re:Go round the side of your house (0)

Anonymous Coward | more than 4 years ago | (#33692340)

You obviously don't know about a season called winter.

Re:Go round the side of your house (3, Funny)

jpapon (1877296) | more than 4 years ago | (#33692500)

Yeah Winter, that's when it rains occasionally, right?


The Bay Area

Re:Go round the side of your house (1)

otopico (32364) | more than 4 years ago | (#33692890)

No, winter is the one where you finally close the windows before going to sleep.

Re:Go round the side of your house (1)

bhcompy (1877290) | more than 4 years ago | (#33693336)

Not quite, you just turn the fan down from high to low. Sincerely, Southern California

Re:Go round the side of your house (2, Funny)

Dishevel (1105119) | more than 4 years ago | (#33693376)

It rains in the winter?

So Cal

Re:Go round the side of your house (1)

treeves (963993) | more than 4 years ago | (#33693856)

Well, it rains much more in the winter but it can rain any time of year.


The Pacific Northwest.

Re:Go round the side of your house (3, Insightful)

lazlo (15906) | more than 4 years ago | (#33693198)

Are you saying you're un-lazy enough to walk a few feet outside and read your meter? And write down the reading? Every five minutes? For a month?

Yes, it's very easy to track your average monthly power usage, it's right there on your bill. It's also easy to check your instantaneous usage by looking at the meter. What the OP wanted to know wasn't just a point measurement, but a running graph to see how it varied from hour to hour throughout the day.

Reading the meter (3, Informative)

SIGBUS (8236) | more than 4 years ago | (#33692194)

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.

Re:Reading the meter (2, Interesting)

markdavis (642305) | more than 4 years ago | (#33692222)

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!

Re:Reading the meter (0, Redundant)

blair1q (305137) | more than 4 years ago | (#33692312)

Here, you dropped this:

you insensitive clods!

Re:Reading the meter (1)

tedpearson (910434) | more than 4 years ago | (#33692404)

I do have a spinning disc. ;)

Re:Reading the meter (0)

Anonymous Coward | more than 4 years ago | (#33692688)

Won't this make the magic go away?

Re:Reading the meter (1)

2.7182 (819680) | more than 4 years ago | (#33693532)

Are you referring the Mana? That's an old story if you are referring is what I am thinking of.

Re:Reading the meter (3, Interesting)

jjhall (555562) | more than 4 years ago | (#33692478)

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. []

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.

Re:Reading the meter (1)

jpapon (1877296) | more than 4 years ago | (#33692522)

You'd think that with all this digitizing of the meters, they would put a simple serial port (or even just some pins) on it so you could monitor it remotely.

they don't want a port that makes free power easy (1)

Joe The Dragon (967727) | more than 4 years ago | (#33692618)

they don't want a port that makes free power easy. No they want to brake the seal to get at that.

Re:they don't want a port that makes free power ea (1)

profplump (309017) | more than 4 years ago | (#33692772)

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.

Re:Reading the meter (1)

markdavis (642305) | more than 4 years ago | (#33692614)

Our meters have a single set of digits showing whole number of kwatt hours. There is no bar chart, no line, nothing else except a tiny blinking triangle (which when I looked at it now is blinking about once per second). No indication as to what the triangle means. It is pretty crappy.

Re:Reading the meter (1)

namgge (777284) | more than 4 years ago | (#33693904)

My digital meter has an led that flashes once per watt-hour. i.e. a 3kW kettle flashes it about once per second. This would be dead easy to interface with an Arduino, but it hardly seems worth the effort. If you want to save power: don't home-work, buy fewer gadgets, wear appropriate clothes, turn stuff off unless you are in the room using it.


Re:Reading the meter (1)

commodore64_love (1445365) | more than 4 years ago | (#33692414)

Before I tackled a similar project, I calculated how much this "real time monitor" would cost, figured out how much I'm likely to save (a few pennies per day), and then decided to buy a $20 gadget on amazon called "Kill A Watt"

It tracks how many KWh a single device (like a TV or freezer) is using. Once a month I look at it, multiply by 9.5 cents, and figure out how much energy it used (typically 1-2 dollars - trivial).

I discovered the appliances use very little energy. Most of the $300 bill is caused by the central Heat Pump, so now I turn if off when I'm not home and also at night (covers keep me warm).

Re:Reading the meter (1)

tedpearson (910434) | more than 4 years ago | (#33692526)

You've neglected the real reason to do this: because I can.

Re:Reading the meter (0)

Anonymous Coward | more than 4 years ago | (#33692960)

You are confused. Monitoring things with toys like kill-a-watts isn't going to tell you much. That shit doesn't even handle 240V circuits let alone all the big hard-wired appliances that are the major power hogs. That's where your energy is going. You need to monitor each circuit at the fusebox, and that costs a fucking fortune. Not that induction systems are hard to make, but the companies that do, want a lot of money. Or you could move to Europe where houses and appliances are much more energy efficient. Clue: hot air blown from heat pumps is the least efficient system you can have.

Re:Reading the meter (0)

Anonymous Coward | more than 4 years ago | (#33693636)

I would have told you that for 5 bucks. I might have told you for free, but I find people don't believe something if they don't pay for it.

Re:Reading the meter (1)

2.7182 (819680) | more than 4 years ago | (#33693660)

And if you want to automate it, but a little wireless camera on it, stream it into matlab, track the image of the spinning disk and count its rotation rate.

The electric meter will sap and impurify you. (1)

wsanders (114993) | more than 4 years ago | (#33693736)

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.

Re:Go round the side of your house (0)

Anonymous Coward | more than 4 years ago | (#33692440)

Actually mine is wireless now.

Is there some way I can receive the data? If not, why not?

Re:Go round the side of your house (1)

RobertM1968 (951074) | more than 4 years ago | (#33692900)

Really? What if one wants to know that they are being billed correctly? BGE is big on overbilling. Heck, we went off grid, and got $2900 in bills for usage we could not have made (meter disconnected - by THEM no less). It took NINE months for them to admit it was some sort of "error" - a fucking "error" that they were claiming the smart meter, disconnected from everything, was reporting such power usage? My ass. Baltimore City was charged a quarter of a million in usage charges for a building that had been taken off grid. Our current LIPA bill here in NY has DOUBLED for some reason, with no new appliances, and no new usage patterns.

Re:Go round the side of your house (0)

Anonymous Coward | more than 4 years ago | (#33692906)

Yeah, that's pretty useful if you can sit their all day every day, but it will tell you nothing about what's using power and it won't help you reduce consumption. You need expensive multi-circuit monitoring. You need to know what line is consuming power and when. E.g. How much is the AC or heat using throughout the day, cooking, washer/dryer. Add in a pool pump, how about the freezer in the garage, fridge in the kitchen, home theatre. Only when you can see where most power is being used are you able to react. You'll learn this when you stop living with your parents and get yourself a tech competent gay lover.

Re:Go round the side of your house (2, Insightful)

Idarubicin (579475) | more than 4 years ago | (#33693102)

Go round the side of your house...And check how fast the dial in the electric meter is spinning.

Which works brilliantly, as long as he's only interested in knowing his electrical consumption while he's outside the house -- and not when he's busy cooking, watching television, ironing, using power tools, or having a hot electrically-heated shower. And as long as he doesn't care about electrical usage while he's asleep at night or when he's at work during the day. And as long as he doesn't mind getting funny numbers because the baseboard heaters in the front hall cycle on for a few minutes every time he opens the front door to go out to read the meter...

Re:Watt's Up Pro (3, Informative)

onebadmutha (785592) | more than 4 years ago | (#33692104)

Stick a webcam on it, do ocr to text on the numbers. Sheesh!

Re:Watt's Up Pro (2, Insightful)

jpapon (1877296) | more than 4 years ago | (#33692250)

You wouldn't even need OCR. Just watch the lowest digit, and count every time it moves!

Re:Watt's Up Pro (2, Funny)

smellsofbikes (890263) | more than 4 years ago | (#33692336)

You joke, but I've done that: put a handheld digital multimeter face-down on a flatbed scanner, and used gocr to get data. It was *very* awkward, and once I got gpib running, I've never looked back at that without shivering.

Re:Watt's Up Pro (1)

tedpearson (910434) | more than 4 years ago | (#33692390)

I'd like to monitor the entire house. I've thought about the whole shebang... monitoring every circuit - but that would be more complex and expensive.

Re:Watt's Up Pro (1)

htdrifter (1392761) | more than 4 years ago | (#33693334)

I'd like to monitor the entire house. I've thought about the whole shebang... monitoring every circuit - but that would be more complex and expensive.

Black and Decker has a unit that mounts on the meter head and gets info from the rotating disk.
There is no wiring involved.
The remote unit recieves the signal and displays power usage, etc.
On the web it's around $70.00.

Black and decker []

get a managed power strip (0)

Anonymous Coward | more than 4 years ago | (#33692056)

They don't cost much ($100-200) and give you all the data you need.

Hmmmm...... (0)

Anonymous Coward | more than 4 years ago | (#33692088)

> though I don't understand circuit design, which is keeping me from designing something myself


Re:Hmmmm...... (0)

Anonymous Coward | more than 4 years ago | (#33692396)

Bah, electricity doesn't hurt too much. Well, unless you are the better ground. And hopefully the ground path isn't through important bits like your chest or head. In one hand and out the other, or a foot, or your head.. That can be bad.

    I've been hit zapped by everything from 90V to 30KV. 120V 60Hz makes a funny tingle, and you can hear the hummmmm of the power line til you manage to let go, which isn't as easy as it sounds... I may have lost feeling in those limbs for a few hours to days, but that warm loving tingling reminds you not to do that again. I'm ... er... shit, 2 years electrocution free. The last one was a fucking camera flash capacitor. Those little fuckers hurt. I think that's it. There may be a few brain cells that released some magic smoke or I'd have more to say on that.

The doc says I'll be fine someday,
once the other voices in my head shut up.

Can't you see I'm trying to type!

Back to your cage!

Who said that?


IObridge (5, Informative)

rodrigo1979 (255519) | more than 4 years ago | (#33692090)

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. [] []

Re:IObridge (3, Informative)

rodrigo1979 (255519) | more than 4 years ago | (#33692538)

Here's the kind of meter we typically provide for commercial building applications: [] That's just the retail cost of the meter.. add the cost of the web appliance (Honeywell/Tridium) with I/O module or Lonworks/modbus interface, plus labor to the electrician for wiring/installation, graphics design, programming the appliance and commissioning the whole enchilada. Not cheap.

Don't look (0)

Anonymous Coward | more than 4 years ago | (#33692094)

Trust me you don't want to know. Just look at your monthly bill and try to do better next month.

Re:Don't look (1)

hierophanta (1345511) | more than 4 years ago | (#33692468)

dont look...just look - make up your mind. also is it possible to not know and have a reference for 'better'?

Tweet-A-Watt (1)

scharkalvin (72228) | more than 4 years ago | (#33692096)

Check out the Tweet-a-watt from AdaFruit.

Re:Tweet-A-Watt (1)

markdavis (642305) | more than 4 years ago | (#33692302)

I am fairly sure he wants to monitor the whole house power usage, real-time. Not just a single outlet.

Re:Tweet-A-Watt (5, Funny)

eln (21727) | more than 4 years ago | (#33692360)

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 whenever you want to know your power usage.

Sheesh, do we have to think of everything?

Very simple... (1)

ThePawArmy (952965) | more than 4 years ago | (#33692204)

1. Point web cam at power meter.
2. Hack software to read pictures of meter
3. ???
4. Profit !!!

I did steps one and two, but no profit... (0)

Anonymous Coward | more than 4 years ago | (#33692280)

I did exactly that... 4.95 euro digital power meter, 200 euro digital camera, 1000 euro computer, and very simple software to analyze power use of cell phone. There you go - el-cheapo power analysis.
Digital readout is way simpler to analyze.

Re:Very simple... (1)

markdavis (642305) | more than 4 years ago | (#33692398)

That is not a useful solution for real-time power monitoring when your digital-only house power meter only displays full kilowatt-hours used. (Hint, my stupid meter is that way).

The Energy Detective (3, Informative)

swillden (191260) | more than 4 years ago | (#33692228)

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.

Re:The Energy Detective (0)

Anonymous Coward | more than 4 years ago | (#33692586)

Exactly. TED is where it's at.

Re:The Energy Detective (2, Informative)

Stele (9443) | more than 4 years ago | (#33692852)

Yep, absolutely fantastic system and not too hard to install yourself. The wireless receiver actually has a built-in web server you can log into from any computer, and "there's an app for that" too. You log into the server, tell it what your energy rates are, and it'll tell you instantly what the electricity is costing you. I have mine sending everything to Google PowerMeter (this feature is built in) which provides very accurate persistent usage data.

I sprung for the optional remote which sits in our kitchen and displays our usage all the time.

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.

Re:The Energy Detective (5, Informative)

swillden (191260) | more than 4 years ago | (#33692996)

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.

Re:The Energy Detective (1)

skipwiley (715786) | more than 4 years ago | (#33693244)

Yes well TED would be great unless you bought a 1001 which they have excluded from compatibility with Google Power Meter. I am not sure why since it has a USB port and it would just take some software on a host to sync the data with Google, instead I have to buy their NEW and improved version to use decent software with it. No Mac support, their Footprints software is dated and slow, and their driver BSODs Windows 7 every 24 hours.

Re:The Energy Detective (1)

CohibaVancouver (864662) | more than 4 years ago | (#33693294)

and dishwasher dominate my power consumption

I've tried to get organized with my dishwasher such that it doesn't dry the dishes electrically any more - I just use it to wash the dishes, then I open the door and pull out the racks and let them air-dry overnight. Works most of the time :)

Google Power Meter / Hackaday Suggestions (2, Informative)

SheeEttin (899897) | more than 4 years ago | (#33692238)

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.

Re:Google Power Meter / Hackaday Suggestions (1)

sconnell (1908466) | more than 4 years ago | (#33693540)

If all you want is graphing, then Google Power Meter is probably the best way.

That may be an option if you are not concerned with accuracy. Also it is not available in every area. In my experience (you can see chart for last month at: [] ), Google Power Meter is off by more than 20%, skips monitoring for entire days and only shows whole house data which doesn't really help you find less obvious "power hogs." We use EcoDog FIDO which shows data for each individual circuit and was accurate with our utility bill within 1KWHr for the month. It also shows the actual cost of the electricity & even accounts for our tiered rates & warns when we're approaching the next higher rate tier. Our utility has been saying that "Google Power Meter has a few bugs to work out..." for about 7 months now. EcoDog showed us that our old dehumidifier in the basement (that we completely forgot about) was costing $90/mo to run. We replaced the dehumidifier with an Energy Star model that paid for itself in 2 months. Unfortunately, EcoDog is quite a bit more than you are looking to spend & we've been running it in VMware on the Mac. They're supposed to come out with a Mac native model next year. It's pretty cool & we figure that we have saved enough electricity to pay for the EcoDog over about a year.

Flukso looks interesting... (2, Informative)

mspohr (589790) | more than 4 years ago | (#33692242)

This product is designed for whole house real time monitoring with the results available on the web... looks interesting. []

Your budget isn't realistic (2, Informative)

dave562 (969951) | more than 4 years ago | (#33692246)

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.

Circut design (1)

mcgrew (92797) | more than 4 years ago | (#33692248)

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.

"Dad monitor" (4, Funny)

NevarMore (248971) | more than 4 years ago | (#33692262)

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.

Re:"Dad monitor" (3, Insightful)

blair1q (305137) | more than 4 years ago | (#33692286)

He's just getting you back for all the times you played kitchen-implement drums while he was trying to nap.

Hug him for it.

Re:"Dad monitor" (1)

tedpearson (910434) | more than 4 years ago | (#33692564)

I do this anyways, as does MY dad.

Re:"Dad monitor" (0)

Anonymous Coward | more than 4 years ago | (#33693160)

Shut up! You're not my real dad anyway! So what if I don't go to school!

For people who do electronics (4, Informative)

smellsofbikes (890263) | more than 4 years ago | (#33692296)

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.

Re:For people who do electronics (0)

Anonymous Coward | more than 4 years ago | (#33692682)

DigiKey has them at $4 for single chips. So this is definitely a cool solution.

Most modern ASICs like that are very simple to work with. Reference designs tend to be more than adequate. Low speed chip interfaces are also very simple.

Re:For people who do electronics (1)

smellsofbikes (890263) | more than 4 years ago | (#33692766)

And Newark has them in stock [] . We've been having a horrible time in the last year trying to find distributors that actually have stuff in stock, and end up buying small lots at high prices from frightening places, or pleading for samples directly from the manufacturers. Parts we've been using for years suddenly have 10 week lead times. I'm trying to source one part the manufacturer swears is in production and rolling off the lines but "nobody's buying" and distributors are showing a 30 *week* lead time. Gah. No wonder nobody's buying.

Re:For people who do electronics (1)

AdamHaun (43173) | more than 4 years ago | (#33693028)

The whole semiconductor industry is backlogged because everyone ramped down their production and laid off people during the financial crash. Now we can't make stuff fast enough despite desperately ramping up and everyone wants to refill their inventory at once.

Most meters can monitored optically (2, Informative)

Anonymous Coward | more than 4 years ago | (#33692308)

See here for a commercial product that exploits this:

You might be surprised ... (3, Interesting)

drachenstern (160456) | more than 4 years ago | (#33692310)

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. []

If you're in with a bigger firm, sorry charlie, not much to suggest there.

Re:You might be surprised ... (1)

tedpearson (910434) | more than 4 years ago | (#33692482)

Still working with a dial meter here. =)

CurrentCost Envi (3, Informative)

Anonymous Coward | more than 4 years ago | (#33692314)

I have an older version of the CurrentCost monitor..

When I get some extra $ together will likely upgrade.

Re:CurrentCost Envi (1)

tedpearson (910434) | more than 4 years ago | (#33692490)

I've read that the CurrentCost monitor isn't very accurate as it has a SET power factor and doesn't calculate the power factor, producing results that can be off as much as 10% or more.

Pick two (1)

LoudMusic (199347) | more than 4 years ago | (#33692318)

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.

Re:Pick two (2, Insightful)

geekoid (135745) | more than 4 years ago | (#33693280)

No he doesn't.

He only needs two: Cheap and good. His requirement doesn't have time. Based on you post it will be perfect, cost him nothing and be done in infinity years... he might was to adjust a little.

This may be what you are looking for... (0)

Anonymous Coward | more than 4 years ago | (#33692352)

Both of these work with Google Powermeter..
(I am personally planning on getting the first one)

Brultech ECM1240 is about $150 in default config (4, Informative)

marcmerlin (48598) | more than 4 years ago | (#33692364)

See []
and see what you can output with one of those guys: []

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).


Re:Brultech ECM1240 is about $150 in default confi (1)

tedpearson (910434) | more than 4 years ago | (#33692504)

Windows initially is fine, I just don't want to run Parallels 24/7.

Re:Brultech ECM1240 is about $150 in default confi (1)

Old time hacker (302793) | more than 4 years ago | (#33692580)

+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...

TED (4, Informative)

Yossarian45793 (617611) | more than 4 years ago | (#33692374)

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.

Re:TED (4, Informative)

GruntMan (669188) | more than 4 years ago | (#33693230)

I have a TED-5000. Very happy with it. 15-minute install in the main panel; the bigger hassle was resetting all the clocks in the house afterwards. Connected the gateway device to my home network, now any device that has a web browser can see power usage. Easily accessible from the outside world by web browser, with the right router settings. Monitoring is down to the second, with a claimed accuracy of +/-2%

Nothing need be installed on the PC, and it doesn't rely on a PC to store data; the gateway device records the data and is the web server.

The manufacturer seems pretty open; they publish the XML format and there are plenty of people reading the device with PHP scripts and logging to SQL databases for more flexible & permanent data storage. There are a few iPhone apps and I think there is a Android app, or talk about one. You can export the data from the gateway in second, minute, hour, daily, or montly format, with the follow capacities:

~2 days of per-minute data
~66 minutes of per-second data
~58 days of per-hour data (likely longer... I've only had mine for 58 days!)

One caveat: the device that connects to the power panel (a pair of current clamps and a pair of voltage taps) communicates with the gateway via power line. Seems like many of the problems people have are related to power line communications, either due to electical noise or other power line communications devices (e.g. X-10) in the house. Some people have success with filters (extra cost), others never seem to solve these problems.

I think it meets the poster's requirements for a), b), and c). It cost me $243 Canadian delivered to my door in 3 days from a Canadian supplier []

No connection to either company here. Just a very happy customer.

Anonymous Coward (0)

Anonymous Coward | more than 4 years ago | (#33692442)

http:// This platform has recording, charts, data export, policies. etc.. you can integrate your sensors and you can modify the platform as well

Budget Buster (1)

HogGeek (456673) | more than 4 years ago | (#33692560)

It's beyond your budget, but a friend of mine was "showing" me his egauge [] ...

About $500

Empower Software. (0)

Anonymous Coward | more than 4 years ago | (#33692582)

Check out:
Might be what you're looking for. Not sure if it's in production yet, though.

KNX? (0)

Anonymous Coward | more than 4 years ago | (#33692686)

Maybe you can find something here:

Jeules (1)

synthparadox (770735) | more than 4 years ago | (#33692722)

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. []

More than $150 but completely awesome (1)

schnozzy (218978) | more than 4 years ago | (#33692784)

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: []

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.

Maybe currentcost (2, Informative)

Booker (6173) | more than 4 years ago | (#33692840)

The currentcost meters are fairly cheap, OSX-capable I think, and very popular in Europe so there are lots of little scripts for them. In the us you can find them at []

The DIY rig at [] 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 [] ...

Re:Maybe currentcost (1)

Oshawapilot (1039614) | more than 4 years ago | (#33693886)

I own a CurrentCost ENVI. The current cost units do have basic device-level drivers for OSX but the interface software required to upload the data to Google Powermeter is (sadly) Windows only. It's one of the biggest gripes in the CurrentCost message forums but the developers appear complacent on the subject.

As such I've been forced to run Windows 24/7 via Parallels with the sole task of running the Google Powermeter application in Windows instead of OSX. Frustrating.

Frustration aside, I do like the unit, but I discovered shortly after my purchase that it only partially supports tiered pricing - it does support two tiers (day and night) with selectable rates and times, but our local utility uses three tiers with each coming into effect at various times of day - off peak, mid peak, and full peak. The ENVI has no ability to be programmed to support this - what I did was program it for the "average" price between mid=peak and on-peak so that it is at least relatively close on the price display.

I'm hoping eventually GPM will also add more options - it supports only *one* tarrif rate, making it even less useful for calculating pricing. It does graph the information nicely though.

Measure electricity, natural gas and water usage (0)

Anonymous Coward | more than 4 years ago | (#33692976)

There is also an system called Enymate on the market which measures all electricity, natural gas and water usage. Here is user review [] how to use this device to save on your natural gas bill.

There are two good devices around that price (0)

Anonymous Coward | more than 4 years ago | (#33693036)

The Energy Detective is pretty good, but I like the Brultech ECM-1240 [] even better.

need individual circuit monitoring (0)

Anonymous Coward | more than 4 years ago | (#33693276)

All these meters measure the entire house together. IMHO what's wanted is a meter with individual current clamps for each circuit (like 20 - 40 current taps), and two or three voltage taps (one per phase).

Such things do exist: half a decade ago I have seen one on offer that had the CT's on PCB's with a spacing meant to match standard American breakers, but it was expensive and had crappy proprietary Windows 3.1 control software so it was a real non-starter.

Trying to correlate which device is using the power by time-of-day is just FAIL, and futile for small-using devices. If the end goal is to correlate behavior with electricity cost, or project the savings an investment in X would bring, more resolution's needed than a single measure for the whole house. Remember, you already have a single meter for the whole house: the one the power company installed! Yeah, it doesn't log, but what's really wanted is OUTLET resolution, not TIME resolution. If you got monthly stats for how much power flowed from each outlet, that'd be a lot more useful for conservation than per-second stats on power for the whole house.

Ideally I would like to see things like power strips that measure per socket, and an overall system that collects data over HomePlug or something, and more devices that report their own use. I should be able to get conclusions like ``this extension cord is costing me 10% extra.''

I really like the original question, though. I worry the ``every little bit counts'' mantra is leading people to compulsively bicker with each other about turning off lights, while washing their clothes in hot water. In effect they are choosing energy saving strategies that inconvenicence themselves as much as possible, because inconvenience assuages guilt, when proper goal-seeking would knock off the power-saving strategies that don't cause inconvenience first. ``Every little bit counts'' could lead to waste as well: for example, hand-washing dishes because people think any involvement of a machine is consumerism america waste blah blah, while in fact hand-washing uses more energy than the better machines.

The place where time resolution might become useful is if you have different electricity rates per hour, but I think few utilities offer that to small customers (most offer it to big ones!).

Zigbee maybe (1)

Darinbob (1142669) | more than 4 years ago | (#33693468)

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.

webcam + image processing + sample db + cache (1)

Mike D. Kristopeit (1900568) | more than 4 years ago | (#33693476)

how about a webcam fixed on your electric meter? some custom image processing software would have to be written, certainly not trivial, but as certainly doable.

from there, dump the samples into a database, build something to cache reports on based on increasing time frames, and build some views and graphs on those caches however you like.

really, the power company should offer you these charts the same as they offer online bill pay.

Run this query ... (0)

Anonymous Coward | more than 4 years ago | (#33693542)

Select * from Google Where accuracy like '.0000?????1' and precision like 'whocares' and OS="darwin" and MadeIn="China" and PNP=true.
You may need to refine the syntax a little, but hey, you want us to do *everything* for you?

I've built my own (2, Informative)

baileydau (1037622) | more than 4 years ago | (#33693686)

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 [] )
    * 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 []

Here is the usage and production for a single day []

Having this type of data is great for tracking down where your usage is going.

Just don't pay your bill (1)

ibsteve2u (1184603) | more than 4 years ago | (#33693696)

They'll call you about once a day, and you divide what they demand right now by your cost per kilowatt/hour.

Overkill DIY solution... (5, Interesting)

dj.delorie (3368) | more than 4 years ago | (#33693768)

I had that desire too, but my electronics skills were up to an overkill DIY solution... []
I record watt-seconds for each of 64 circuits once per second to a linux server.

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