Electrical Device Detection

Howdy All,

I’ve been using EmonPi for a few months now and while I was doing some other research (typical link surfing) I came across an energy monitor that caught my attention.

It claims that it can identify what device is being used by the noise/interference from the power line.

I can understand that this is possible as in essence, this is how ethernet over powerline adapters work.
I can understand that each device has it’s own distinct power draw profile (unless it’s a heating element as the draw and resistance changes as it heats up)
The only issue I can see so far (bearing in mind this was a passing thought), is if electrical devices have a similar draw/noise profile on the powerline and the system couldn’t distinguish between the 2. E.G 2 vacuum cleaners of the same make and mode.

While writing this a suggested article popped up

I’ve no idea if this is the same thing as I don’t understand fully what’s being discussed in the article.

Either way, if there was a way of identifying what electrical device is being used and how much power it’s using, then that would just be nothing short of amazing!
I know that there are plugs that you can add in between the wall outlet and the electrical device but this is somewhat of a pain in the behind to go round every single device and measure it.

Do you think this is even possible to build this into EmonPi?

In short, no. I rather doubt that any one technique will be the answer. What you mention might be useful to providing additional data that can’t be got from measuring the characteristics of the current drawn, but even so I think you’d need to rather a lot more processing power, and a much higher sampling rate for voltage and currents, than an emonPi can provide.

What you’re talking about has been the Holy Grail of energy monitoring for a long time. Many well-funded (presumably?) firms have tried and launched products, I believe based on measuring current, inrush, harmonics etc, but from what little I’ve seen, they all struggle and while many appliances can be distinguished, so far anything anywhere near total accuracy has been impossible.

The problem I see with r.f. is it’s a fickle beast, and it won’t need much of a change to the system to alter the characteristics of the generated emissions. It’s going to interesting to see how this progresses.

One device that claims to recognize power signatures is the “Sense Energy Monitor” available from Amazon. The company claims “Over time, Sense’s machine learning algorithms identify unique signatures in the power use of individual devices within your home and match them against a growing database of appliances and home electronics.”
However reviewers report that while the device measures total load accurately, it does not do a good job at sorting out individual loads.

Smappee was another device that made similar claims, and also failed to produce meaningful results.

Thank you all for the replies.
Very interesting responses.

I wonder if there could be either something built into a socket or an additional plug that the device plugs into to enable something like the emonPi to identify that particular device?
A bit like how a network works, by adding specific encapsulated identifying information into the current/draw or something of that device.
The additional plug could be a temporary thing until the system learns that characteristics of that particular device and knows what to ‘listen for’ from then on.

Also a while ago before smart plugs became as advanced as they are now, there was a powerline adapter that used x-10 protocols to communicated with a central controller. Each plug had a manual dial on it that you could set to identify that particular plug so you could switch it on/off.

Once each device had been profiled, it may not need to be done again for a couple of years or the device gets changed.
As a device ages, I’m sure whatever r.f noise it makes changes as motors wear or consumption characteristics change etc.

Sorry, just vocalising ideas here.

@Bill - Smappee was the one I was thinking of, just couldn’t remember the name of it at the time of writing.