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Monitoring Home Power Consumption for less than $25

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Re: Monitoring Home Power Consumption for less than $25

#61

Post by alkonaut »

emilburzo wrote: post #53
alkonaut wrote: post #45

Is it really required to actually read currents to achieve the power measurement? do meters in individual buildings not have interval-flashing LED's for power consumption in the US (I'm assuming the target market is the US)? A flashing LED is neat because you can then use a very simple-to-install adhesive photodiode to count the flashes and radio the results back to some reader (e.g. 1000 impulses per kWh). Doesn't r…

Would nobody bat an eye if you had an electronic device attached to the meter? (especially the guy that comes and does the meter reading)

No, the meter is sealed, which is the benefit of this type of arrangement. The meter just sits attached to the meter on the outside, so it's obvious that nothing is tampered with. Many power companies even sell their own (branded) kits that does this.

It's also very rare to have someone come read the meter. Like all other parts of society anything that can be automated at almost any cost has been already. I have had no one read water or power meters for many years.

Re: Monitoring Home Power Consumption for less than $25

#62

Post by rootw0rm »

jstanley wrote: post #48
mattmanser wrote: post #46

Earlier quoted context omitted.

In the UK we have smart meters now[1]. They tell me how much I'm using at any time for free. Why not just use one of them? Or are they not in your area yet. To be honest, having had one, anything that makes water hot is expensive, everything else is cheap. Before winter hit I was using a 1/5th the electricity I am now (useless storage heaters). TVs, computers, etc. are not worth really worrying about. Although, even…

> Why not just use one of them? Because you don't want your electricity meter to have the ability to be remotely-instructed to disconnect your electricity supply, and you don't want your electricity meter to have the ability to record fine-grained data about your electricity usage patterns, which it is required to store for 13 months, and which you can't actually know for sure isn't sent off remotely even if you opt…

I'm from California, where they can justify a raid based on your power usage. "You're using twice as much power as your neighbors, you must be growing cannabis indoors!".

I can definitely say you are justified in your skepticism regarding the utility-provided equipment.

Re: Monitoring Home Power Consumption for less than $25

#63

Post by emilburzo »

alkonaut wrote: post #61
emilburzo wrote: post #53

Earlier quoted context omitted.

Would nobody bat an eye if you had an electronic device attached to the meter? (especially the guy that comes and does the meter reading)

No, the meter is sealed, which is the benefit of this type of arrangement. The meter just sits attached to the meter on the outside, so it's obvious that nothing is tampered with. Many power companies even sell their own (branded) kits that does this. It's also very rare to have someone come read the meter. Like all other parts of society anything that can be automated at almost any cost has been already. I have had…

> I have had no one read water or power meters for many years.

Ah, that makes more sense now :)

Over here we still have people that come to read the meters every 3 months.

Re: Monitoring Home Power Consumption for less than $25

#65

Post by wcoenen »

SergeAx wrote: post #49

It is extremely strange they don't use even primitive encryption. I work for Russian company "Strizh Telematics", we are making smart resource meters. We take security very seriously here: all transmits are encrypted with 64 bit keys and data protocols are specifically protected from statistical and repeat-packet attacks.

Why 64 bit? The minimum key strength supported by AES is 128 bits, so 64 bits seems very low.

Re: Monitoring Home Power Consumption for less than $25

#66

Post by raesene9 »

mattmanser wrote: post #46
raesene9 wrote: post #41

In the UK I just use one of these https://loopenergysaver.com/ You connect the reader around the mains supply cable, plug the other end into an Ethernet port and it works. No monthly subscription charges, just the initial cost of the device which is £60 at the moment. Not the most high tech solution but seems to work pretty reliably

In the UK we have smart meters now[1]. They tell me how much I'm using at any time for free. Why not just use one of them? Or are they not in your area yet. To be honest, having had one, anything that makes water hot is expensive, everything else is cheap. Before winter hit I was using a 1/5th the electricity I am now (useless storage heaters). TVs, computers, etc. are not worth really worrying about. Although, even…

We've not been offerred a smart meter as yet.

I've also got some reservations about the security of the smart meter systems, so ideally I'd like to wait as long as possible for those to get ironed out, before I get one.

Re: Monitoring Home Power Consumption for less than $25

#67

Post by cbr » 

    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 much too low-resolution for this.

RTL-SDR monitoring would actually be awesome to add to Sense: the method it uses for measuring current is designed for microsecond-level accuracy, not long-term accuracy like your meter. So over time they won't keep perfectly in sync. If Sense could automatically read your meter it could calibrate itself.

Re: Monitoring Home Power Consumption for less than $25

#68

Post by daenney »

I do something similar at home. However, the meter in my house has a LED that blinks per Wh used, so all I did is put something light sensitive on top of it, wire it to a tiny board of your choice (GPIO on a Raspberry Pi in this case) and then export the data from there. I run a tiny Prometheus exporter on that same Pi which gets scraped and everything neatly shows up in Grafana.

For other devices I use Z-wave powered sockets which do power metering, which is exposed by another Prometheus exporter. Since those Z-Wave sockets can be on the expensive side I only really use them in places I want to meassure, like my desk (which has laptop, screen etc.) or the TV.

Re: Monitoring Home Power Consumption for less than $25

#69

Post by mrb »

SergeAx wrote: post #49

It is extremely strange they don't use even primitive encryption. I work for Russian company "Strizh Telematics", we are making smart resource meters. We take security very seriously here: all transmits are encrypted with 64 bit keys and data protocols are specifically protected from statistical and repeat-packet attacks.

That's great, but using a 64-bit key in 2017 isn't "taking security seriously". Especially if you are designing meters that will have a lifespan of 10+ years, therefore must be secure until 2027 and beyond.
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