/ Home & Energy

Smart meters – will you use yours?

Smart meter

It’s hard to believe we wouldn’t turn off our gadgets if we knew how much cash we’d actually save by doing so. Why then does new research say we’re not interested?

Don’t you want to know how much that extra boil of the kettle or TV left on standby costs? PassivSystems’ latest research says two-thirds of us wouldn’t act on the information provided by an energy smart meter, even if we had one installed.

But this is at odds with our latest research here at Which? – only a quarter of you said smart meters wouldn’t make a difference to you at home.

What exactly is a smart meter?

I’d strongly suspect that the recent glut of research taking it in turns to lampoon and applaud the smart meter roll-out is more a reflection of ignorance about smart meters than pure apathy.

Confusion about the differences between smart meters and energy monitors is rife. Fact: smart meters don’t tell you how much you’re spending on electricity, energy monitors do.

Smart meters were designed to send real-time energy usage data directly to energy suppliers, heralding an end to ‘getting the meter read’ and the horrors of estimated bills. But in their basic form, smart meters don’t provide any meaningful information about actual energy costs to the consumer at all.

Only through using an additional energy display will you see your household’s real-time energy use and costs. Which? has successfully campaigned for these displays to come with smart meters, since they let you see how much energy’s been used whenever you want. This information could help guide you to the most cost effective energy tariff and help work out where you can cut energy use to save money.

Results muddied by dubious motives

The negative vibes from the folk down at PassivSystems are likely due to the fact that they’re in the business of energy. I have no doubt that they’re aware of the differences between smart meters and energy monitors. But it’s in PassivSystems’ interest to fan the flames of confusion and scepticism.

It is, after all, a company that specialises in selling pricey smart technology to turn your heating appliances off for you. The last thing it needs is for us to believe that turning off electrical gadgets ourselves is all it takes to save money and feel environmentally upright.

In the press release that accompanied its results, PassivSystems CEO Colin Calder was scathing about government plans for smart meters, saying “smart meters are not an attractive or compelling proposition for the end-user”.

But perhaps it’s PassivSystems that should be worried. If three-quarters of people wouldn’t act on energy data, how many of them are going to splash £400 on an intelligent energy control system?

Chris Plymouth says:
1 July 2010

It may be a shock to see how much power a kettle uses, but it’s not going to stop you having a cup of tea.


We all love a cup of tea, however the kettle often fill with excess water which is not utilised for the cupper..
Fill the cup/s and empty into the kettle before boiling to minimise wasted energy.

Richard says:
1 July 2010

I was a bit gutted when I realised smart meters would actually save my utility company quite a bit of cash while giving me, well, not much. Or anything!?

So onto energy monitors. Sounds lovely but no, they won’t stop me boiling the kettle. What one might do, though, is to show me how much energy different appliances use and so cost me. I have naff all idea of this at the moment. Think it would work particularly well at my parents’ place where they’ve got things they don’t have to run (e.g. dishwasher, tumble dryer).

But could energy monitors tell me whether it’s cheaper to fill two basins full with washing up water when doing a bit post-roast wash-up or to run the dishwasher?


I think I’d quite like to know how much energy my TV uses on standby, or my washing machine after one load. To then know how much hard earned cash that actually turns into, might make me cut back in the future.

Damn Young says:
3 August 2011

My Hotpoint washing machine takes no power at all. Not since I ripped all the electrical parts out of it, and attached a handle for manually turning the drum.

Aly123 says:
2 July 2010

I had an energy monitor and for a while it was fascinating watching how it would spike when certain appliances went on. However, the novelty soon wore off (particularly over a cold and wet winter when drying clothes outside isnt an option) – and then it ran out of batteries. I’m more interested in having appliances that are more economical to run – but with the latest increase due in VAT that’s putting up those costs as well…

Tom Ritchie says:
3 July 2010

If you look at the experience of the water industry, you can clearly see that households with water meters use significantly less water (about 30% less?) than those without. And this is happening despite the fact that you don’t get a monitor in the house telling you how much water you have actually used day-to-day.

I find it hard to believe that the introduction of energy meters would not prompt a similar cut back in energy use.

Liz says:
12 July 2010

I have some concerns about smart meters, but I’ve also come across people who’ve gone for many months with a (wrongly) estimated bill and then been hit with a massive one they weren’t expecting but still had to pay. I think this will stop with smart meters, so that is one thing in their favour.

Richard says:
22 July 2010

That is a very good point which I didn't know about.

Still gutted 'smart' meters are mainly for energy cos.' benefit, though not surprised.

Michael Shere-Massey says:
21 July 2010

The only one to benefit from smart meters will be the utility company itself,who will of course pass on the savings to us…??? and legions of meter readers will pay the price.
Oh..and guess who will end up paying for these devices to be installed.?


Smart meters. You’v got one and want to switch.
Alternative suppliers may not accept the one you’ve got. So getting in early with something non standard may not have been a great idea.

Bob says:
24 July 2010

I am sorry but the cost of doing something I want to do anyway & the cost of doing it does not worry me in the slightest as I will do it anyway what ever it costs otherwise we shall never do anything in our lives . So people will not turn on the tv or radio , cooker , The elderly will not turn on heating in winter because the meter tells them that you are using ££££ , I think it better we do not know & just pay the bill when it arrives as we have always done , we never have had problems with the old system so I will not even look at THE THING even if it is fitted , What a waste of money on a brainless idea .What Will Be The Next Brainstorm To Be Pushed On To Us As , So many people will sit for hours after turning on an appliance just to see the cost Baaa .


Smart Meters will be useful in one respect: ending estimated bills (as mentioned above) which are due to the infuriating habit that the Meter Readers have of coming to the door and posting a card saying "sorry you were out" without even ringing the bell.
I have watched this happen at least 6 times at my own home and my mum has experienced it countless times as have many people I work with. If you dash to the door fast enough and catch them most of these readers are very offhand (not to say offensive) about actually having to come in and read the meter, some even refuse to do so. Some of the colleagues who have had this experience even have meters in boxes outside the front of their houses, so it’s clearly a "can’t be bothered" rather than a "tried but could not" issue.
On the other side of the coin, using an energy monitor has helped me to prove to Trading Standards that a new washer, rated A++ for energy efficiency, actually used around 4 times as much power as the 23 year old one that it replaced. Needless to say the new one very soon found itself traded in for a 20 year old one which not only uses less power again (same energy monitor to check this) but also works better. In the same way I have monitored power use of other appliances and found that my old kettle uses less power than my new one (not a lower wattage but boils faster so using less electricity). This has heightened my awareness of how new appliances often use more than old ones, even when they are hailed to be "energy efficient" and, after a protracted exchange of correspondence with an officer at EST I did get a written confirmation that the vast majority of new appliances DO use more energy than their old counter-parts, but are ranked only against EACH OTHER for efficiency.
So, Smart Meters are welcome to ensure correct billing, but I don’t see why on earth the consumers should be expected to pay for them and I can’t see how in themselves they will make the slightest difference to the energy we use. Energy monitors, on the other hand, are very useful but might well give some unexpected and possibly (if you have just spent loads on supposedly "green" appliances) unwelcome results!
Caveat Emptor?


My electricity supplier in its wisdom has sent us an Energy Monitor. The fitting instructions could be understood by a small child – if only my meter had the slightest resemblance to the one illustrated.
As it is there is absolutely no way I could fit the thing to their meter, so it stays in its box. A total waste of money.
So I’ll never know how many watts it takes to boil a kettle – tough.

Damn Young says:
3 August 2011

You can boil a kettle with 1 Watt or 1000Watts, it just depends how long you’re prepared to wait.


My mother-in-law is 90 and a leaseholder from a social landlord.

She likes to keep man eye on utility expenses but we have recently discovered that the landlord has allowed (grossly-over)estimated bills for communal electricity to run an-and-on with spasmodic refunds. This makes it impossible to work out what exactly has been consumed.

With smart meters available, there should be penalties on landlords who allow this to happen

Betty says:
20 August 2010

Is it really true that many new appliances use more electricity than some of the older ones ?
I have a very old. but completely reliable fridge, which suits my needs exactly, but Which? seems to always be insisting that old appliances like this are very wasteful on electricity compared to new ones. This has made me wonder if I should ditch my old ‘friend’ for a new one to save on electricity uses. Is there any way of finding out more details about the energy uses of new machines before one buys one. Relying on A & A++ does not seem very satisfactory


It was only after fitting a free energy monitor that I realised just how much power was being used by a b****y teenager running her electric heater totally needlessly in her bedroom, even going out to college without switching it off.
A Godsend!


Betty – I absolutely agree with you and in fact on the discussion thread can small changes help the environment (here is the link: https://conversation.which.co.uk/energy-home/can-small-changes-help-save-the-environment) I have gone on and on (sorry to anyone who thought I went too far!) about the bitter disappointments and frustrations that my neighbour and I have had with a new gas boiler and a new washing machine respectively.

Even where a new product actually does use less energy, the reduction is often so tiny that it will never pay for the investment so it is well worth using your old appliance as long as it will work.
These are not just my own pet theories: if you look at the Radio 4 “Money Box” and “You and Yours” archives on line you should be able to find a programme from You and Yours in around December 2009 / January 2010 where they got the then Government Minister in charge ofthe boiler scrappage scheme on and gave him a real grilling about who would actually benefit from getting a new boiler. When he was presented with scientific facts and really backed into a corner he was forced to admit that if you have a boiler which is working, regardless of it’s age or type, and you replaced it with the most efficient model it is possible to buy, you would be looking at a saving of less than £400 in gas at the current prices when the programme went out OVER THE ENTIRE LIFE OF THE NEW BOILER (which I seem to think they estimated to be around 8 years). Given that the researchers for the programme had found that the average cost of buying and having installed a new boiler was around £3,500, that means that over the life of the boiler you would LOSE about £3,000.

In a similar way the boss of one of the major high street electrical retailers was taken to task on an early Spring 2010 edition of Money Box over a promotion his company was running to entice people to trade in old style CRT TV’s and buy new Flat Screen models. It didn’t take a lot of pressure from teh presenters before the man admitted that if you buy a flat screen TV of a given size it will use almost exactly double the electricity of the identical sized CRT set. For example my old CRT 21″ TV is rated at 170 Watts so according to that programme a Flat Screen 21″ set will use about 360 watts. There is, however, some good news on the TV front: the latest LED TV’s do actually use only about the same power as an old CRT set, although they appear to be very expensive to buy as yet.

The big problem, though, is actually getting to find out what the REAL energy consumption of an appliance will be before you buy: the data is presented in such ambiguous ways that it is incredibly hard to know whether a new item will be better / worse than or the same as your old appliance. This is compounded by new appliances often working in different ways from old ones, so you are not comparing like with like.

If you take my advice, Betty, you won’t replace anything unless it is completely worn out and beyond all repairs. Quite apart form the energy savings (or not) it is extremely rare to buy anything these days that is built to last and so you will probably create 4 or 5 lots of waste products in the same length of time that an old appliance would have been scrapped just once: even though that is not energy use it is still bad for the environment and your purse!

Damn Young says:
3 August 2011

I investigated the TV usage. My 32″ Sony flat screen tube TV took pretty much the same power as my 32″ LCD TV. At least I can get into the room now the Sony has gone.


Jennifer (Harrison) above makes a good point: I bought an energy monitor a little while ago (I wish I had waited until the energy company gave them away as they are doing now, but that is beside the point).

I was lucky and had no trouble setting it up at all, but then some work colleagues started asking about it and saying that they could not work out how to fit one and I discovered, from their experiences, that a) there are many different types of meter so (as Jennifer says) it’s hard to know what you are looking for on some meters and b) some meters, especially as far as I can see the ones in the cabinets outside your house, have all the wires completely concealed inside sealed up plastic and bakelite covers, so you cannot attach the sensor at all.

They certainly don’t make it easy to be green!

John Fitz-Hugh says:
27 August 2010

Energy monitors, as commonly supplied for monitoring whole house electricity consumption, are not accurate for a large range of appliances that are commonly found in the home. The monitors normally measure the current (amps) being supplied to the house using a clamp-on current transformer that is fitted around one wire of the supply near the household electricity meter. The amps reading is then multiplied, within the monitor, by an assumed supply voltage to obtain the product amps times volts which is then displayed on the monitor as watts. However, for alternating current, like our mains electricity supply, the power in watts is volts times amps times power factor and this last item, “power factor” is not measured by these monitors. Instead, they assume the power factor has the value one. This is only correct for heating loads like ovens, irons, toasters, kettles, incandescent filament lamps. Appliances with motors and/or electronics in them can have power factors much less than one. On some devices like phone chargers, it could be as low as 0.2. On some fridges it is as low as 0.6. If the power factor of a particular appliance were say 0.5, then these energy monitors would display its power consumption as twice the correct value.
In addition, the assumed supply voltage may well be somewhat different from the actual supply voltage which will in any case vary from time to time.
Thus using an energy monitor can give misleading information. The household electricity supply meter, whether smart or not, measures and displays the true power consumed, i,e. it correctly measures and accounts for power factor and supply voltage as well as current.
As more people use energy monitors within their homes, it is only a matter of time before the discrepancy in measurement of power between an energy monitor and a household supply meter leads to confusion and disputes.
I am writing this detailed lengthy technical comment because I have been amazed that such a fundamental problem with these simple energy monitors has not been aired in public by “Which” or anyone else. The public need to be warned of the limitations of such monitors.
Note, I am NOT saying such monitors are useless, merely that they have limitations which people need to take into consideration.


John Fitz-Hugh’s point is a very good one indeed, and one which I must say I was partially aware of and yet failed to take into account in my own experimentation with appliances which seemed to be green but in fact were not.
However, the saving in energy between my last quarterly bill and the one before that came from the Electricity companies bills and accurate readings and covered a time span where my overall consumption on items other than the washer I got Trading Standards involved with went up rather than down (for example with the onset of summer my garden water features were switched on after winter dormancy and with the long summer holiday starting I have run the dishwasher most days rather than once a week) so I am confident altho although my energy monitor may not be completely accurate, it was giving a reasonably good indication.
John’s amazement that Which? or some other group has not started to alert everyone to this issue is a very important point though – perhaps Which? could do an in-depth report into Monitors and ensure that the issues raised by John are prominent within that?

John Fitz-Hugh says:
30 August 2010

I notice that “Which” has tested energy monitors. When you tested them, what was the power factor of the load(s) that you used? Did you test them using loads with a range of power factors? If so, what was this range and did you find that the accuracy of the monitor varied with the power factor of the load used? If you did not test them over a range of power factors, was there any reason why you did not do so?



Thanks for all your comments. John – I’ve had a chat with our lab experts and power factors and they told me the following:

‘Yes, these type of energy monitors only measure the current flowing through the mains input cable and assume a voltage of 240V (some models are adjustable) and don’t automatically compensate for a change in supply voltage.

‘Therefore the information given by these monitors can only really be considered a guide, and is not as accurate as the electricity meter which will have been calibrated during production and is designed to compensate for the variations in supply and load.

‘Having said this it is likely that the average household load will be mainly resistive with only a proportionally small amount likely to move the power factor away from unity.’

Hope this helps?

John Fitz-Hugh says:
14 October 2010

Thank you for your reply which I did not find particularly helpful because it did not answer the questions that I asked in my comment posted on 30/8/10. In my opinion, for the reasons that I stated in my comment posted on 27/8/10, these monitors give inaccurate and misleading results when monitoring loads that have power factors significantly less than one and I think your published test report on these monitors should have stated this.


I think John’s point actually raises another one that needs to be publicised a great deal: Joe Blogg’s average consumer, and even Miss Blogg’s average Which? member of staff, don’t have the necessary scientific knowledge to understand how these devices work and therefore understand how accurate or not they may be.

Damn Young says:
3 August 2011

Fortunately, the meters don’t understand either. They charge us for Amps times Volts, but when the amps are drawn out of phase with the volts, we get cheap electricity.


New meters, not “smart” meters.
Please stop calling the new type of kWh meters smart, they are not smart. The only thing about them that is smart is sales spin intended to sell the idea to the largely uniformed public. The main gain is for the supply companies to reduce the cost of meter reading and so increase their profits.
Regarding the comments on monitors, they should be called volt ampere monitors unles they compute true watts by measuring actual volts, amps and power factor.Your experts comments regarding power factor is not strictly true, in the case of a washing machine the power factof may well be 1 during the initial water heating phase but the next phase invoves a motor to drive the drum and pump water out during the washing and rinsing phases. The motor will have a power factor much less than 1. It would be interesting if you can publish a recording of the kW versa time during the complete washing cycle for a machine.
It would also be helpfull if you could gather all the comments on meters, bills, tarrifs and OFGEM on the same or adjacent pages instead of being scattered across the existig 14 pages.

Damn Young says:
3 August 2011

They should have been called ‘Invasive Meters’, but that would be bad spin.


I’m not sure that it is worth mentioning power factor on a non-technical forum, especially since there is not much users can do to change the electrical load characteristics of their washing machine. All that the average user needs to know is the how the cost of running different washing machines compare, and hopefully the ratings on new appliances reflect the cost.

What concerns me more is that gas price is now shown in kWh. Electric heaters can be nearly 100% efficient but that’s certainly not the case with gas. Fortunately, most of the general public are well aware that electric heating is relatively expensive.


Last year my energy supplier sent me free of charge the energy monitor rated by Which? as their Best Buy. Being a bit of an anorak I decided to find out the consumption of every appliance and electric light circuit in my house and started by switching everything off and pulling all the fuses in my consumer unit.
I was therefore very surprised to find a large usage of electricity when I plugged back in one of the fuses associated with my lights, because none of them were switched on. I eventually traced the problem to an old strip light in the garage which had no lamp fitted. The fitting was drawing so much electricity I calculated the annual cost to be £210. An energy efficient light was fitted in it’s place immediately.
Informing my friend Harry of this he used a similar energy monitor at his house and had a very similar experience. Also in his garage he had a separate spur consumer unit. With everything in his garage switched off the garage was drawing a huge amount of electricity. He looked at this unit during the dark and the rear of it was glowing red which could easily have caused a fire if it had not been discovered. This led to a new consumer unit being fitted. We estimated the annual electricity being wasted to cost £1200.
I would therefore recommend to anyone to obtain the energy monitor recommended by Which? and carry out a thorough audit of their energy consumption. In both mine and Harry’s case it has saved us a fortune.


Concerning the comments made by a few people above regarding power factoring I fell foul of this when using the energy monitor recommended by Which? as their Best Buy. It is the type which has a transmitter that wraps around your house’s main power cable and sends readings to a display you carry around with you.
I had my house fitted with energy efficient LED bulbs which the manufacturer claimed to use only 4 watts of power per bulb. But when I turned a bank of these lights on my energy monitor told me the bulbs used an average of 8 watts each. I brought this to the attention of my supplier who kindly went back to the manufacturer for an answer. The answer was that the lamps have a power factor of 0.5 which I wasn’t taking into account.
I believed I was being spun a yarn to get rid of me. But at the same time I was given the type of energy monitor that plugs into a wall socket and directly monitors the power consumption of an appliance plugged into it. I wired up some LED bulbs to a 13amp plug and this monitor correctly gave me the power consumption of 4 watts per bulb and is in fact accurate to 0.1watt.
If you really want to measure accurately the consumption of an individual appliance I suggest this is the more accurate type of energy monitor and will in fact tell you the total amount of energy used by a washing machine or dishwasher over the complete wash cycle.
However I agree with Which? that their Best Buy monitor is ideal in that it is fully portable and you can see in real time what effect switching an appliance on or off has from anywhere around your house.

George Wood says:
18 January 2012

Smart Meter Roll-Out, Questions to Chris Huhne, DECC 18 January 2012, 14.30 hours

1.What are the true costs of the smart meter roll-out programme?

2. Two years ago I looked at DECC data and figures of £10-billion for 2010 and £10.75-billion for 2011 were quoted. This clearly didn’t happen and now a figure of £11.1-billion is being quoted which is just over half the original quotation. Is this lower cost of roll-out because any additional connections to appliances in the home will become their own responsibility. Surely, the total cost of smart meters will in the end fall on the electricity consumers.

3. How can a figure of £11.1-billion be charged to consumers with no perceived or stated benefits?, apart from more accurate meter readings.

4. You say benefits of £18.1-billion will accrue from the roll-out of smart meters over time. What benefits are these? Can they be defined and evaluated in an unbiased way.

5. Do such benefits actually exist?

6. Are the £18.1 billion of benefits derived as a result of demonstrating that you are saving on the capacity costs of building new power stations and infrastructure at the margin? If so security of supply is being compromised.

7. Are you intending these smart meters to be switchable?

8. If you are intending to use smart meters for switching loads in homes, offices and manufacturing to avoid the marginal capacity costs, then it should be classed as a demand disconnection plan to stop the lights going out.

9. Please state your purpose for the massive £18-billion savings roles that you quote.

10. Would it not be better to invest £11.1-billion in new CCGT power stations that can ensure the countries security of supply is met?

Claire says:
10 October 2012

I think smart meters are a really great idea.

George Wood says:
10 October 2012

Smart meters will cost around £20-billion to roll-out across the UK, as a whole.

That’s £600 per household. All though originally DECC initially listed about £15-billion for the whole country. Its a bit like HS2, smart meters are being foisted upon us without the facts being spealt out to us and then voted upon.

There is no real cost-benefit, all though DECC claims that we will save £17-billion. Yes DECC claims we will all be better off from having them. Well you will be charged $600 per household for the privilege hrough your electricity bill over time.

This is all pie in the sky as the real benefit to each and everyone of us is miniscule. But we are all being hoodwinked into believing we need a smart meter.

Make no mistake this is all linked to the ‘Energy Market Reform’ where the market will eventually stir the capacity cost of generation into the instantaneous half-hourly market price. Do you really want to be frightened into switching your electricity off just when you need it the most, on a cold dark winters night at about 17.30 hours towards the end of January?. Well thats what the outcome is being planned to bee!!!

The market will say the price is approaching £100/kW through your smart meter and you will panic and switch off all electrical appliances and sit in the dark. The people that wise up before the event will buy a little standby petrol or diesel generator for about £500 and switch over to that instead of taking electricity from the mains when the price starts rising, even above £1.00/kWh.

This is the way most of the major power companies are envisaging the ‘Energy Market Reform’ to take.

So now you need a £500 standby Generator and yet you will still be lumbered at paying for your smart meter at an average of £600 per household.

This is what is termed ‘free market enterprise’. Now do you really want that gimmicky ‘smart meter’ because this is what is being channelled as the eventual outcome.

George Wood