Smart Meter per-device usage - how does it know?!?

moneyspendy

After getting a SmartMeter fitted about a year ago, we get regular mails from our supplier EDF with nice pie charts, consumption graphs etc.

Recently one caught our eye which claimed that our fridge was responsible for about 25% of our annual electricity consumption. We live in a 1900's-era flat with probably 80's -era wiring, no smart plugs or whatever, so my question is: how can they possibly know this? I can only imagine they are either basing this on typical customer consumption patterns, i.e. guessing, or - just conceivably - basing it on certain usage patterns in the use of current e.g. medium draw device running 24/7 with occasional upticks. But I find to hard to believe they are *that* sophisticated?

Can anyone enlighten me?

(In answer to my own question - I'm guessing it probably doesn't?)

Swipe

It doesn't. It's just silly shenanigans by EDF.

[Deleted User]

There was a lot of research done to see if you could read the "noise" in the system and match it to appliances (even to the point of using it to find developing faults with wiring).

Didn't really work back then though, and was never included in smart meters iirc.

pochase

Not completely true, it is possible, but not by a standard smart meter.

In 2015 I purchased a third party (clamp) add on from "Smappee" that was able to recognise different device by their signature. You had to teach them what device was what, but you could see in detail what your electricity was used for.

https://www.amazon.co.uk/Smappee-Home-Energy-Monitor-UK/dp/B00W5D5W3A/ref=cm_cr_arp_d_product_top?ie=UTF8

Support for the device was dropped two or three years ago.

[Deleted User]

Octopus was promoting this company a year or so ago. A small credit card size device is installed on the DIN rail in the consumer box (if you have space).

https://voltaware.com/

pochase

Yep, seems to be exactly the same principle, they are also using the unique "fingerprint".

It would show you a list of all devices that are currently using electricity, and you could assign a name to it.

[Deleted User]

We could never get it to work well in the lab for anything that had a power converter - it couldn't tell the difference between laptop charger, digibox, etc.  It was reasonable at learning things with an obvious and/or spiky pattern, and better still at looking backwards at a day to guess at what had been used (rather than real time).

[Deleted User]

[Deleted User] said:

We could never get it to work well in the lab for anything that had a power converter - it couldn't tell the difference between laptop charger, digibox, etc.  It was reasonable at learning things with an obvious and/or spiky pattern, and better still at looking backwards at a day to guess at what had been used (rather than real time).

I agree. I am still not sure why people actually want that level of granularity. It is very easy to see baseload in the home by looking at 30 minute usage overnight. 

jak22

It can either be an estimate based on typical consumption of a fridge or done by looking at the overnight consumption which is fairly flat with devices on standby and then increasing for periods as the fridge turns on and off.

Although ridiculed my some those monthly consumption estimates are at least worth looking at. It's extra information to add to your own observations of the IHD as things get turned on and off during the day to understand where the money's going

wild666

Back in August 2016 my provider at the time BG sent a letter saying what each appliance had used in the last 12 months and they claimed the TV had used about £17 but the only appliance resembling a TV that was on was the PC monitor. I hadn't even used the PS4 in the last 12 months, this possibly shows that they cannot differentiate between a TV with a tuning device that saves live TV channels and a PC monitor that shows websites. 

MattMattMattUK

That EDF system was still saying that I was using my heating in June, it seems to be an uneducated guess at best and entirely pointless.

Edit to add, I have just looked at the figures from EDF for July, these show how out they are.
Lighting: They think I used 6kWh of electricity on lighting, that means roughly, based on the light bulbs I have fitted, I was running a lightbulb 28.8 hours a day, now I could have been running many simultaneously, but I was not, my total usage on lighting would be around 0.4kWh per month.
Home Entertainment: 52kWh, I have estimated my usage, being that July was lovely weather and I was not home much, not watching much TV, not playing many games (rebuilding gaming PC and PS5 was mostly off, due to being in the pub), at the top end I think I probably used 32kWh.
Hot Water: 14kWh, my home is all electric, I shower every day, at a minimum this would have been around 45-50kWh, it was probably 60-65kWh. 
Heating this month is zero, however it thought I used 87kWh in May and 34kWh in June, my heating has not been on since late January or early February.