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Are smart meters overcharging?

Posted by Gabby Mallett on 14 March 2017 at 11:23 am

I know I have written much about how great smart meters could be. They will help us to get rid of the antiquated idea of estimated bills, they will make is easier for everyone to see where they are using energy and they will make it much much easier for people to switch supplier.  But all of this is based on the assumption that they smart meters are accurate.

A new study by some clever people in the Netherlands (University of Twente Enschede and Amsterdam University of Applied Sciences) has calculated that some of these meters actually provide readings which are almost six times higher than they should be.

In Holland, just like here, there is a big push to install smart meters. They have about 750,000 installed and we had 4.05 million by end of September last year. That’s quite a few meters that could be wrong.  And when I say wrong, I don’t mean giving readings of £30,000 for a day’s use, which were reported last week. I mean just reading slightly more on everything.

The universities made up circuits where different appliances, like LED lights, were added and the smart meter used to measure electrical energy use.  They, of course being clever people, knew how much energy they were putting in to the systems, so they knew immediately that there was something not quite right.  They tested nine different meter types (yes, some which are in use in the UK) and five of them showed higher readings than the actual energy used. Readings that were up to 583% higher, with the biggest differences occurring where dimmer switches were used with LED bulbs. 

Prof Leferink, the author of the report, 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."

In fact, two of the meters gave readings that were actually 30% lower than anticipated.

So what does this all tell us? Not much really.  We don’t actually know if the old meters were accurate. These meters are clearly not 100% spot on all the time, but what they do give which we didn’t have before is easy access to the data.  As soon as someone sees their bill going to £30,000 in one day they take note. If one day you use 56p worth of energy and another you use £2.16, you will ask yourself why? This study didn’t test the measurement of gas use which doesn’t use the same switching technologies and is therefore likely to be more accurate.  Heating usually makes up a much greater proportion of your energy use, so this is the bit which you really want to be spot on.


Photo: David Dodge

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7 comments - read them below or add one


richmcComment left on: 6 April 2017 at 8:30 am

Tomm Bragg, 24.99p/ unit for 4-7pm is tantermount to theft! Thats when most households will be preparing the evening meal probably using an electric oven, and with no choice. I pay 15p/unit 24/7 and with no standing charge, how is varible tarrif ever going to benifit the consumer, it's just an excuse for power companies to charge more instead of fixing the problem, with say Hydro storage systems.

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Tom Bragg

Tom BraggComment left on: 5 April 2017 at 11:41 am

The long-term green advantage of smart meters will be time-of-use electricity tariffs, costing more during peak demand and less at night.  Green Energy UK's TIDE tariff already offers this in England: 24.99p/ unit for 4-7pm on weekdays, 4.99p for 11pm-6am, and 11.99p in between.  It's like a more flexible Economy 7 tariff with one meter - ideal for anyone charging electric cars overnight!   I'm signing up, thinking about what consumption we can shift from peak times. When this becomes widespread, peak demand will reduce, so that fewer power stations will be needed.

Smart appliances may help us shift consumption, such as heat-pumps, washing machines and freezers that normally avoid using electricity at peak times.

UK industry commonly use half-hourly meters, which are compulsory for big consumers. Tariffs can have a different electricity cost in any half hour. In the future these prices may vary dynamically, depending on the predicted state of electricity supply and demand.

These smart meter errors are very concerning, but I think they'll be ironed out. The study described in this blog investigated inaccuracies caused by electro-magnetic interference (as from noisy PV invertors) conducted through the mains to the meters.

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NEF Gabby

NEF GabbyComment left on: 3 April 2017 at 8:36 am

Andy in Hawick

It sounds as though you have found out a bit more than me and I think this is getting a bit outside my area of expertise. 

Any engineers out there fancy doing some research for us?



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NEF Gabby

NEF GabbyComment left on: 3 April 2017 at 8:34 am

richmc and mymalestado 

I can tell you exactly what is wrong with estimated bills. 1) they are estimated incorrectly and 2) it almost always in favour of the energy supplier.  What happens is they charge too much (probably keeping our hard earned cash in a high interest account somewhere) and they tell us they are building up a buffer for the winter months or to make sure we can cope with pay rises.  But actually many many people have 'buffers' that are far bigger than necessary.  We actually had one customer who was £3,000 in credit (yes that's three thousand pounds) you can search NEF+£3000+"affordable warmth" for more details.

And, yes of course we can send in meter readings online.  Sadly some people find accessing their meter difficult, others don't find them easy to read and plenty of people don't (or can't) access their accounts online. In fact this all affects older people more, they certainly seem the least likely to switch supplier.

Anyway, I still think smart meters could be very useful for some people, but I am not sure that all of the kinks have been ironed out yet.





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Andy in Hawick

Andy in HawickComment left on: 1 April 2017 at 10:55 am

What would be helpful is an analysis of the smart meters that are certified for use in UK and the type of current measuring device used, the multiplication device employed to calculate the instantaneous power and the integration mechanism that computes the energy.

I contacted my energy supplier to ask what type of smart meters they install and what current measurement device they use. They informed me that it is the Liberty 110 that they use and that it has a shunt for current measurement, which is very straightforward and direct and will not suffer the problems of the Robowski coil or hall effect devices that are used in the meters that gave inaccurate readings.

I'm looking forward to having a reliable near-realtime display of my electricity use; both power & energy.

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muymalestadoComment left on: 31 March 2017 at 8:00 pm

Since when was an estimated reading been so dreadful? Since when was a consumer not able to record usage in a personal table and send in a reading to their supplier - I do each month. Since when have mobile phone cameras broken up when recording the meter for onward transmission to the supplier. Since when have our 'normal' meters required neighbourhood transciever towers to capture everyone's data.

I do not get what the benefit is. Oh, wait. This initiative comes from the industry and is backed by hype and hyperbole. Ah, yes this is all for the benefit of the industry.

What I will miss is the irregular, infrequent visit from the meter person. Because they discovered our quite normal wee house had two meters listed with serial numbers which did not match the one meter we've used for decades. And then discovered on the next visit the fix was to change the two S/N so it was no fix at all.

Would a smart meter have uncovered that? Open question.

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richmcComment left on: 31 March 2017 at 6:24 pm


They are touted as helping to save the consumer money by allowing the energy companies to charge less for power off peak, if you fall for that one you need your bumps felt, they will allow the power companies to charge MORE during peak times.

For those of us with PV they also act as an export meter, how long will it be before the 50% useage is payment is replaced by a real reading, as somone with battery storeage who during the winter feeds in nothing I will be losing out.

There have been instances in the news about smart devices being hacked and abused, theres nothing to stop it happening to smart meters, and your information being sold on.

Although the govenment wants us all to have these things by 2020 there is legislation in place that says "WE ARE NOT OBLIGED TO HAVE ONE FITTED".

How are these smart meters more user friendly than just taking a reading and submitting it on line? A simple tast that if you forget the only result is an estimated reading, hardly the end of the world.

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