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Monitoring Home Power Consumption for less than $25

blog.kroy.io

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Re: Monitoring Home Power Consumption for less than $25

#121

Post by Mister_Snuggles »

phubbard wrote: post #117
Mister_Snuggles wrote: post #112

Reading this piqued my interest as this is something I’ve wanted to do ever since my local electric company started to roll out smart meters. I took a look at my electric company’s web site to see what kind of meters they use and it turns out that they have already seen this need. They will enable the ZigBee module in the meters and set it up to talk to a home energy monitoring device (which you have to buy separatel…

I built a purely local version using the Raven USB Zigbee modem, flask and D3.js. Crude, uses SQLite but might be of interest. The XML decoding is only hard part really. https://github.com/phubbard/raven-peewee

Cool!

Did you have any trouble convincing your utility company to enable the ZigBee module? Or do they do things differently?

Re: Monitoring Home Power Consumption for less than $25

#122

Post by SergeAx »

mrb wrote: post #118
SergeAx wrote: post #77

Earlier quoted context omitted.

Our most talkative meters are currently broadcasting 4 packets of data per hour. Water meters with autonomous power are limited to one or two (for central hot water supply) packets per day. With all the randomness added collecting data for successful key bruteforcing will take months or even years. On the other hand, using 64 bits allows us to use 16- or even 8-bit microcontrollers, which is beneficial to power consu…

I can't speak to the specifics of your project, but 128-bit symmetric crypto on 8-bit microcontrollers is perfectly possible, at a low power budget and with relatively small code and RAM usage.

When we were looking at the task of creating autonomous battery-powered reasonably-sized device with 6 years lifespan - we took into consideration every single point where we could conserve power. Now we have what we have, not what you think we could have. Feel free to try and break our encryption with couple kilobytes of ciphertext on hands - you will have a prize of reading your neighbour's water consumption data on a daily basis)

Re: Monitoring Home Power Consumption for less than $25

#123

Post by calmconviction »

PoachedSausage wrote: post #35
lucaspiller wrote: post #11

Earlier quoted context omitted.

You can also buy clamp sensors that can be connected directly to a microcontroller (with an ADC - so not a Raspberry Pi without external hardware). http://www.homautomation.org/2013/09/17/current-monitoring-w...

The clamp only systems lack accuracy due to not measuring supply voltage. Commercial/open source energy meters based on chips like the ADE7953[0] have a resistive voltage divider to attenuate the supply voltage to suitable level for the chip but preserving the envelope for sampling. The problem is there is no galvanic isolation, so interfacing is harder. [0] http://www.analog.com/en/products/analog-to-digital-convert…

I have a similar set up with a Z-wave clamp style current meter[0]. This meter is calibrated to 120v. I use NUT to grab the line voltage off the UPS and adjust the reported current with actual voltage to get power. It's good enough for the girls I go out with

[0] https://www.amazon.com/Aeon-Labs-AEDSB09104ZWUS-Aeotec-Monit...

Re: Monitoring Home Power Consumption for less than $25

#125

Post by Too »

lucaspiller wrote: post #11
linker3000 wrote: post #9

* OWL power monitor with inductive clamp and separate LCD display (in the reduced bin at the local DIY barn), transmits data on 433MHz - £12 * Arduino Mega+ESP8266 combo board - £8 * Rflink Rx/TX board - order a kit or build your own ( http://www.rflink.nl/blog2/wiring ) 433 or 868MHz operation, can also work with some devices at 2.4GHz - About £15 * Rflink software ( http://www.rflink.nl/blog2/ ) + Serial link softw…

You can also buy clamp sensors that can be connected directly to a microcontroller (with an ADC - so not a Raspberry Pi without external hardware). http://www.homautomation.org/2013/09/17/current-monitoring-w...

If you got 3 phases going into your house, how would you use this sensor? Do you need 2, or even 3, of them?

Re: Monitoring Home Power Consumption for less than $25

#126

Post by rthille »

kabes wrote: post #18
JSONwebtoken wrote: post #10

I hadn't heard of the company Sense before I read about this blog. I looked up their product... 300 bucks, are you kidding me? And it requires licensed installation on top of that, so maybe even more in labor. Who's buying this stuff and how is their margin defensible from Tesla or somebody selling Raspberry Pi kits for $25?

Of course the people without the technical skills, but also everybody who counts their time in terms of money. I used to reason like you when I was a student and had seemingly unlimited time on my hands. But now I'm a consultant who bills by the hour which makes me somehow always translate time into money. If I bill $100/hour and the raspberry PI solution would take me a day to set up and working, then buying the sen…

Sense looks really attractive to me, except the part where they get all the data. If they had a self hosted solution that I could run on a Raspberry Pi or even a “real”computer to do the data collection and processing, I’d be in.

Re: Monitoring Home Power Consumption for less than $25

#127

Post by collinmanderson »

disillusioned wrote: post #7

This is neat. I had vaguely heard of the RTL-SDR, but this is a cool example of a potential application. A few points of note: The author starts off by discussing how the Sense energy monitor piqued his interest, but he didn't want to go through the trouble of installing it. My understanding is that Sense offers granular usage data down to the appliance level, which reading polled usage off the meter simply won't do.…

> reading polled usage off the meter simply won't do

(I'm duping this comment from above) I've been recording my power and gas usage via RTL-SDR for over a year. You only get a data point a few times a minute (if that). However, I can usually (though not always), with context, tell that a big spike was my hot water heater vs air conditioner, etc.

Re: Monitoring Home Power Consumption for less than $25

#128

Post by collinmanderson »

cbr wrote: post #67

I am bombarded with ads on Facebook for the Sense. This device allows you to monitor whole-home power consumption. ... I realized it would be extremely simple to do something similar without any wires or hassle. Sense monitors two things: * instantaneous current * instantaneous voltage Different devices have different electrical signatures, and this allows it to learn what devices you have in your house. RTL-SDR is m…

I've been recording my power and gas usage via RTL-SDR for over a year. You only get a data point a few times a minute (if that). However, I can usually (though not always), with context, tell that a big spike was my hot water heater vs air conditioner, etc.

(Though it's not enough to get totals for the day/month/year per appliance.)

Re: Monitoring Home Power Consumption for less than $25

#129

Post by AdamJacobMuller »

calmconviction wrote: post #123
PoachedSausage wrote: post #35

Earlier quoted context omitted.

The clamp only systems lack accuracy due to not measuring supply voltage. Commercial/open source energy meters based on chips like the ADE7953[0] have a resistive voltage divider to attenuate the supply voltage to suitable level for the chip but preserving the envelope for sampling. The problem is there is no galvanic isolation, so interfacing is harder. [0] http://www.analog.com/en/products/analog-to-digital-convert…

I have a similar set up with a Z-wave clamp style current meter[0]. This meter is calibrated to 120v. I use NUT to grab the line voltage off the UPS and adjust the reported current with actual voltage to get power. It's good enough for the girls I go out with [0] https://www.amazon.com/Aeon-Labs-AEDSB09104ZWUS-Aeotec-Monit...

I have the same meter, that meter actually reports voltage to me though.

Re: Monitoring Home Power Consumption for less than $25

#130

Post by AdamJacobMuller »

lucaspiller wrote: post #107
ris wrote: post #85

Earlier quoted context omitted.

> Of four recources commonly metered in Russia - electricity, water, gas and heat When you say "heat" - is this steam from a combined heat & power plant? I was aware these were quite widespread in Russia but didn't know they were metered.

It's fairly common in eastern and northern Europe too. In my building there is a single heat pipe from the city, however each unit has it's own meter for cold water, hot water (for taps) and hot water (for heating). The hot water meters are different in that the first measures the water flow, and the later measures the heat flow.

Does it recycle the cooled water back into the system?
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