Temp Posted March 7, 2017 Share Posted March 7, 2017 From todays Telegraph.. http://www.telegraph.co.uk/news/2017/03/06/smart-energy-meters-giving-readings-seven-times-high-study-finds/ Highlights.. Smart energy meters giving readings up to six times too high, study finds Smart meters are giving readings up to six times higher than the energy consumed by households when connected to energy-saving light bulbs, according to scientists. So called "green" devices such as energy saving light bulbs, heaters, LED bulbs and dimmers change the shape of electric currents which can result in a distorted reading, it said. The greatest inaccuracies were seen when dimmers combined with energy saving light bulbs and LED bulbs were connected to the system. Five out of nine smart meter models tested gave readings which were too high, the study found. The author of the report, Prof Leferink, said: "We've known since 2009 electronic meters can give readings which are too low. But this is the first time we've seen they can be much too high. We were flabbergasted by our results. "The study was carried out in a laboratory setting. If you looked at ones in homes I don't expect they would be 500 or 600 per cent out. But what we have shown is the reading can clearly deviate a lot from the power customers are actually consuming." and can anyone explain this bit.... "It is alarming, but it does not necessarily mean people have lost money. Smart meters are essentially a 'second check' as energy suppliers keep a record of energy consumption and if there is a discrepancy, they will know." Link to comment Share on other sites More sharing options...
Jeremy Harris Posted March 7, 2017 Share Posted March 7, 2017 (edited) My understanding is that the smart meters effectively have two metering systems. One is the standard metering system that used in pretty much all electronic meters, and does do pretty good power factor correction. This is used internally to run the standard meter part of the meter and is to the same accuracy standard as any other meter. The other is the remote display data transmission, that is supposedly "instantaneous" power. I used an electricity meter chip as the front end for my excess PV diverter, and that samples at 900kHz with a 16 bit resolution, on both the voltage and current waveforms, so does a pretty good job of coping with things like switched mode power supplies, etc, that have a fairly nasty current waveform. This bit of the meter is pretty standard and is the "master meter", if you like, that runs the display on the smart meter itself and logs the energy usage to internal non-volatile registers. The second part is less accurate, as it has to be in order to be able to transmit "instantaneous" power usage to the indoor display. The problem is one of integration time, as I found when making my own wireless indoor display. The way the metering works is based on measuring true energy, in Wh, and so to get "instantaneous" power you have to choose an averaging period to convert Wh to W. In my case I chose 10 seconds, as a reasonable compromise between accuracy and display functionality. I don't know what averaging period smart meters use for the remote power display, but it's likely that they do something similar. If I were to calculate energy from the power averaged over 10 seconds at the internal display, in order to be able to make that internal display show Wh, or cost, there would always be an error. Over time, that error would get larger, as the internal wireless display doesn't know the total Wh recorded in the registers inside the master meter chip. There is a way of reading these registers, and it may well be that a smart meter can be interrogated to get an accurate energy reading, which may well be very different to the reading on an internal display. Interestingly all the meter chips I looked at had bidirectional energy metering internally, so could easily be used as export meters if need be. Edited March 7, 2017 by JSHarris Link to comment Share on other sites More sharing options...
curlewhouse Posted March 22, 2017 Share Posted March 22, 2017 "It is alarming, but it does not necessarily mean people have lost money. Smart meters are essentially a 'second check' as energy suppliers keep a record of energy consumption and if there is a discrepancy, they will know." ...... presumably the same energy suppliers we hear giving little old ladies £20,000 electricity bills for a quarter year and in insisting they are correct, threatening court etc? I think we can trust the big suppliers to act sensibly in such cases about as far as we can throw them! (which means not very far) Link to comment Share on other sites More sharing options...
SteamyTea Posted March 22, 2017 Share Posted March 22, 2017 In these cases where people are sent preposterous bills, is it the meter that is faulty, or something further up the chain? Link to comment Share on other sites More sharing options...
Guest Alphonsox Posted May 23, 2017 Share Posted May 23, 2017 Interesting piece in the Telegraph today - http://www.telegraph.co.uk/money/consumer-affairs/no-ones-noticed-tories-quietly-killing-smart-meter-revolution/ Link to comment Share on other sites More sharing options...
PeterW Posted May 23, 2017 Share Posted May 23, 2017 Gets my vote ..!! Anyone who has a meter more than 15m from the house is stuffed anyway as the units won't work ... Link to comment Share on other sites More sharing options...
ProDave Posted May 23, 2017 Share Posted May 23, 2017 A victory for common sense. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted May 23, 2017 Share Posted May 23, 2017 I'm just a bit peeved that I didn't need to turn our meter box into a Faraday cage, to stop these daft things working, after all.................... 1 Link to comment Share on other sites More sharing options...
Stones Posted May 23, 2017 Share Posted May 23, 2017 21 minutes ago, ProDave said: A victory for common sense. Indeed, although a victory for political self interest is probably closer to the mark... 1 Link to comment Share on other sites More sharing options...
SteamyTea Posted May 23, 2017 Share Posted May 23, 2017 It is another example of why governments/parliament should not be allowed to make technical decisions. What are the odds that Hinkley gets cancelled at great expense next, or will they just wait for EDF to go bust. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted May 24, 2017 Share Posted May 24, 2017 Interestingly, I've just had a call from British Gas. It went like this: British Gas (BG): Your meter is due for replacement and we would like to make an appointment to change it, please. Me: No problem, I can be in anytime, but the meter was only replaced a few years ago, so why does it need replacing again? BG: It's a part of our nation wide meter change programme, which we are rolling out in your area now. Me: Does this mean that I have to have the meter changed? BG: Yes, your area is part of our current programme. Me: Is this new meter a Smart Meter? BG: Yes Me: I don't want a Smart Meter. BG: That's alright, I'll just take your details and mark you as having opted out. Me: Are you still going to change my meter? BG: No, it's not due for replacement yet. The initial contact was a bit more than confusing, it was deliberately worded to make it seem as if this was a routine meter change. If I didn't know that having a Smart Meter is voluntary, then one would have been fitted. I would hazard a guess that a fair number of people are going to be duped into having these things fitted. Link to comment Share on other sites More sharing options...
Kuro507 Posted May 24, 2017 Share Posted May 24, 2017 (edited) In fairness, I tried to get one installed at my current house via Ovo, two cancelled installation appoinjtments later, was then told by installers they have nobody to cover my area... no further date can be given. I thought it would be a good idea for me with a electric car on order, to have been visibility and more accurate billing. Edited May 24, 2017 by Kuro507 Link to comment Share on other sites More sharing options...
Ferdinand Posted May 24, 2017 Share Posted May 24, 2017 (edited) 10 minutes ago, Kuro507 said: Whats your objection to a smart meter? In fairness, I tried to get one installed at my current house via Ovo, two cancelled installation appoinjtments later, was then told by installers they have nobody to cover my area... no further date can be given. I thought it would be a good idea for me with a electric car on order, to have been visibility and more accurate billing. They are not secure enough, they are not universally compatible between different companies, and they potentially give outside bodies the power to control my electricity without me being able to do very much about it easily or necessarily knowing what is happening, or consenting, That is why I refused one. Edited May 24, 2017 by Ferdinand 1 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted May 24, 2017 Share Posted May 24, 2017 15 minutes ago, Kuro507 said: In fairness, I tried to get one installed at my current house via Ovo, two cancelled installation appoinjtments later, was then told by installers they have nobody to cover my area... no further date can be given. I thought it would be a good idea for me with a electric car on order, to have been visibility and more accurate billing. You can get exactly the same electricity usage information by just fitting a simple wireless energy monitor, in fact we have one that British Gas handed out free a few years ago when we switched to them. Smart Meters have no advantages for consumers, in fact the limited evidence so far suggests they are causing significant billing problems, for a host of reasons. Also, as Ferdinand rightly says, they are insecure and give utility companies a lot of potential control over your supply (the latter being why they are so enthusiastic about them). There's also a major problem at the moment in that there is a lack of proper compatibility between meters from different suppliers. Change energy supplier and you may well find that your Smart Meter stops working as a Smart Meter, and reverts back to being a dumb meter. If I was at all cynical, I'd say that this may well be a deliberate move to try and encourage customers to stay with a particular supplier, rather than look around for the best deal each year or so. 1 Link to comment Share on other sites More sharing options...
Jeremy Harris Posted May 26, 2017 Share Posted May 26, 2017 Would you believe it! British Gas have been on the phone again, yesterday lunchtime with a "silent call" from their 08000 725230 number, same again today except I answered the call, as I did on Wednesday. Same conversation as recounted above. They don't seem to have done as they said they would and permanently marked us as not wanting a Smart Meter. Time to switch suppliers, I think, as I can't be done with being hassled like this by nuisance calls. Link to comment Share on other sites More sharing options...
Temp Posted May 27, 2017 Author Share Posted May 27, 2017 BG rang me some time ago. The man told me that my meter was "out of date" and that they "needed" to come fit a new smart meter. Since we had the meter installed when we built the house I knew exactly how old it was. Link to comment Share on other sites More sharing options...
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