Ecoisme power meter - Page 1
Forum section: electronics / general

author: mciancia
author_rank: Newbie
timestamp: May 20, 2015, 08:18:27 pm
content: https://www.indiegogo.com/projects/ecoisme-intelligent-energy-monitoring-system#/storyWhat do you think about this?Idea is nice, one device for monitoring power consumption of everything in home, but can this really work?

author: ataradov
author_rank: Super Contributor
timestamp: May 20, 2015, 08:58:33 pm
content: This will be a fail. It has everything going for it - well designed kickstarter page, a young team full of CEOs, CTOs ans other O's. A lot of marketing mumbo jumbo on a page and zero details on the principle of operation.

author: ataradov
author_rank: Super Contributor
timestamp: May 20, 2015, 09:01:59 pm
content: Well, I just noticed that it is also an indiegogo with flexible funding, which means that it is 100% scam.

author: senso
author_rank: Frequent Contributor
timestamp: May 21, 2015, 03:37:34 pm
content: If it was on Kickstarter it would be a smash, but Europe can't access kickstarter...It doesn't look like a blatant scam, there is prototypes, and real board are shown..

author: suicidaleggroll
author_rank: Super Contributor
timestamp: May 21, 2015, 04:18:41 pm
content: Quote from: ataradov on May 20, 2015, 08:58:33 pmI thought they were pretty clear on the principle of operation. Wall socket to measure voltage, clamp meter on the main fuse box to measure current, basic power analysis to identify simple devices and spectral analysis to identify more complicated devices. They even showed an example of the data when switching on and off a macbook. It seems straight forward in theory, but how well it actually works is another matter.For example, I bet the power signature of my PS4 looks very different if it's sitting idle, playing a blu ray, playing Netflix, watching a pre-rendered cinematic in a game, versus actually playing a game, and that's just for one device in my house. Calibrating this thing could be a huge PITA.

author: ataradov
author_rank: Super Contributor
timestamp: May 21, 2015, 04:19:15 pm
content: Ok, but flexible funding? Are they going to make molded cases if funding stops now? They will have to add a lot more to pay for molding forms.Presumably they want all requested funds to get economy of scale.Yes, there are boards, I have no doubt that you can measure total consumed power by measuring line voltage and current. I'm not so sure about differentiating devices by their line noise. Especially in presence of microwave ovens and refrigerators.

author: ruffy91
author_rank: Regular Contributor
timestamp: May 21, 2015, 04:22:24 pm
content: I think it will work. I have used a devkit from ST (power meter mcu) which I used to monitor power consumption. You can differentiate between most appliances solely using power consumption.

author: ataradov
author_rank: Super Contributor
timestamp: May 22, 2015, 04:55:00 am
content: No, you don't. According to their idea you have just one device that sits on the main power line going into your house. It then analyzes power consumption profile of the entire house and tells what is on on the inside.

author: tom66
author_rank: Super Contributor
timestamp: May 22, 2015, 12:18:23 pm
content: Most devices >70W use active PFC. It will be hard to do spectral analysis on these devices as they are designed to reduce it.Perhaps it could work by "learning", i.e. you turn off all devices, then turn on the TV, say that looks like the TV, etc.Maybe with a very fast ADC you could pick up certain SMPS frequencies - but I would say this would be tricky to do reliably. There'd also be a lot of processing involved and expensive ADCs if that was the method.I can tell when my plasma TV is switched on when looking at the house load current because it makes the mains current wobulate at an offset frequency - the display flashes at 100Hz (14SF x 100Hz - drawing current as required but dominated by last few SFs), but the mains is at 50.1Hz, the pulsations are visible in the input current. And of course being a plasma the input current varies wildly from sub 200mA to 2A.For certain specific loads it MAY be able to determine what is switched on - the problem is it will probably require frequent re-training if new devices are added, and it might struggle as the number of devices increases.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: May 22, 2015, 02:43:32 pm
content: Quote from: mojo-chan on May 22, 2015, 11:40:37 amIt's explained pretty clearly in the campaign, and I also re-explained it earlier in this very thread:Quote from: suicidaleggrollSo in short, there isone deviceat the main power box, and it's analyzing the power level and line noise to determine which devices are switched on.Quote from: tom66Yes, this is exactly what the campaign page says that it does:Quote

author: wraper
author_rank: Unknown
timestamp: May 22, 2015, 02:52:10 pm
content: Quote from: ataradov on May 22, 2015, 04:55:00 amSomething tells me, that this would be difficult to do. Particularly in my case, I have a PC which can draw anywhere between 120W to 750W of power depending on what I'm doing on it. How this thing will be able to reliably detect my oscilloscope, signal gen or tiny phone charger being switched on combined with such changing power consumption on the background, is beyond me.

author: ataradov
author_rank: Super Contributor
timestamp: May 22, 2015, 03:50:46 pm
content: Quote from: wraper on May 22, 2015, 02:52:10 pmThat is my exact point. I think they are getting ahead of themselves.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: May 22, 2015, 05:01:24 pm
content: Yeah, I would be very surprised if this device didn't have a ton of false positives, false negatives, and misidentifications in any kind of modern household.

author: mjkuwp
author_rank: Unknown
timestamp: May 23, 2015, 01:58:24 am
content: one thing that helps; there are two sides to the US electrical panels so it only has to decode from 50% of your objects (of those that have fixed positions)I think detection will be difficult to impossible but for the sake of discussion, assume the device can detect individual loads properly.What do you do with the information?

author: tom66
author_rank: Super Contributor
timestamp: May 24, 2015, 02:11:14 pm
content: If you captured say 1MSPS data over 30 seconds and did an FFT on that data you could probably pick out some patterns. Would take a fairly powerful solution; I don't think a basic ARM MCU will cut it, unfortunately.I'd say you'd want a higher bit depth ADC, some of the harmonics will be quite far down in amplitude due to line noise filters built into appliances.The main issue I see is it's quite likely that the signature of a device will change rapidly depending on load/usage. So if you train it to look for a computer with signature X, how would it know about that computer when you start playing a game and pulling more watts? It would need to look at long term usage trends to pick out these signatures with any confidence -- but how would you gather that data? It's not as simple as turning the device on for 30 seconds. It needs to see the long term usage.I very much doubt this can actually calculate watts used per device as the power usage will be in the 1st & 3rd harmonics primarily, like every other device.

author: Howardlong
author_rank: Super Contributor
timestamp: May 24, 2015, 05:53:02 pm
content: Regardless of the technicalities, there are eight individuals and five "advisors" on this project. That's at least ten too many on a project of this size.

author: MadModder
author_rank: Regular Contributor
timestamp: May 24, 2015, 06:54:42 pm
content: Quote from: senso on May 21, 2015, 03:37:34 pmWhat do you mean Europe can't access kickstarter? I have backed a few projects from the UK. And last time I checked UK is part of Europe...And backers from Europe have no issues accessing it either.They add countries every now and then. Right now it says:"Project creation is currently available to individuals in the US, UK, Canada, Australia, New Zealand, the Netherlands, Denmark, Ireland, Norway, Sweden, Germany, France, and Spain who meet the requirements below."So not the entire Europe, but 9 countries.Not Poland though. I wonder how they decide which countries should be allowed...

author: coppice
author_rank: Super Contributor
timestamp: May 24, 2015, 07:27:47 pm
content: A number of companies have worked on this problem. Intel famously sunk quite a bit into it, and failed. A few products with limited goals, like TheEnergyDetective.com exist. Some startups have come, run out of money before they got very far, and have gone. Others are still working on it.These efforts have mostly been driven by observations in the 1980s that you can easily see the pattern of many appliances switching on and off, just by looking at a plot of a home's total power consumption against time. Automating this, and making it accurate is still a work in progress, and I think it will get harder. As others have commented, the increasing use of PFC and continuously variable drive motors, is making the power profile of appliances more bland, rather than more characterful. If you can identify anything, it might be more likely that you can say "A device with a model xxxxx PFC controller just turned on", rather than be able to say "An xxxxx just turned on". Being able to reliably identify a few high consumption appliances, like heaters and air cons, seems much more likely than being able to break down everything in the house.If you look at the web site they talk about going from a poor power measurement unit, to a good power measurement unit, to a unit which can break down the power spectrum. This doesn't sound a lot like people working at the advanced end of the power metering business.