3-phase Smart Meter installs in UK - when will they happen?

  • DeLory's Avatar
    Level 1

    When will 3-phase smart meters be available?

    I wanted to start this thread to ask the question and capture any useful information in one place as it seems to be rare in the UK to have a domestic 3-phase supply. I realise that not many people are in the same situation as me.

    I've been asking for many many years - six or seven at least - over four different suppliers about getting a smart meter installed for the 3-phase supply to my larger house, but it's still nowhere in sight even though it's been promised since at least 2018.

    This tantalising story and video from August 2020 shows that it is possible in the UK, but the person in the story was an employee of the power supplier which obviously helps.

    The current answer is that a 3-phase smart meter is not available.

    What is 3-phase?

    In case you're wondering what 3-phase is and why is it needed, please let me explain briefly. The usual single-phase 240V supply in most people's houses is good to supply up to 60amps, allowing about 14kW of power (240 x 60 = 14400) to be supplied at one time. In practice this means an electric shower and some electric heating. But if you add another electric shower or you want to charge an electric car then your peak demand for electricity might be higher than 14kW.

    That's where a 3-phase supply helps. Each of the three phases can supply up to 100amps, though it's unlikely you'll ever need as much as that. It's a big change because you need the local electricity network company (not the same as your electricity supplier) to run a new 3-phase cable to your house from the cable in the street (which is already 3-phase) and install the new main fuses (3 of them, one for each phase) and a new 3-phase meter. You will also need an electrician to install a 3-phase distribution board (that holds the circuit breakers) and balance the demands in your house across each phase so, for example, putting the two electric showers on different phases and your double oven on the third phase. At the same time, they might also install the high-power charging point for your new electric car which will use all three phases. In future, we may also replace a gas boiler with an electric boiler or a heat pump which also need a lot of power.

    3-phase smart meters in other countries
    Let's be clear, 3-phase smart meters do actually exist in the world. In Australia, the heavy electric demands of air-conditioning require 3-phase supplies and the sunny weather makes large solar electric installations a no-brainer, and in Germany I've read that most new houses are built with 3-phase supplies to allow for the demands of electric car charging.

    3-phase and smart meters in the UK
    A large solar panel system also needs the power that it generates to be distributed evenly across the 3 phases. In the UK, you can only attach up to 4kWp of solar panels per phase, so the 12kWp system in the story I linked above requires a 3-phase supply and smart meter. The smart meter has to measure the balance of generation and consumption across each phase and add it together intelligently to give a reading of how much power you've consumed or generated. This will vary across the day because, for example, some panels start to become shaded as the sun moves across the sky so they don't generate as much power, and someone has an electric shower or starts the washing machine. It's a complex picture.

    As I understand it, there are three parts necessary before 3-phase smart meters can be installed:
    1. the meter itself
    2. a connection from the meter to the DCC, the national UK organisation that receives the data from each smart meter
    3. the billing system at each electricity supplier

    All these aspects have to be working together before any smart meter can actually be smart.

    Almost done...
    If you're still reading this far, let me add in some more aspects:

    Smart meters can enable time-of-day charging by the suppliers, where your electricity price changes depending on the time of day. The highest charges are at peak time in the morning and most of the evening when most people are active, a "middle" charge during the day between the morning and evening peaks, then a lower charge late evening and overnight. This makes us change our usage habits to reduce what we pay.

    A battery storage system in your house might also help where you can charge it overnight at a cheaper night rate then use it during the morning peak time, for example, to avoid using peak-rate electricity. This is not as simple as it sounds because each time you convert the energy, putting it in to the battery or taking it out, you lose some power in the conversion, so the peak rate cost would have to be a lot higher to make this behaviour worthwhile.

    A house battery system can store the output from roof solar panels when you're out during the day, but if more people are working from home then your panels will power your working day instead of charging the battery.

    Eventually the large battery in your electric car will be integrated into the electricity system of your house. This means that when and how much you use your car has to be added in to the mix as well.

    So, yes, this is going to cost money. And much of it won't be worth doing for many people, but suppliers and the power network companies need to be trying this out now with real customers to find out what works and what doesn't so we can all benefit.

    Well done - you've reached the end!
    As you can see, there's a huge potential that 3-phase smart meters can unlock. It's well past time that they're available to install.

    But what can I do?
    I'd be interested in any experience, answers, further information or anything you think might be useful to add here. I'm not expecting any immediate answers from Eon through Forum Admins - companies are busy trying to stay in business and manage all the changes in price cap and government help - but some idea of any internal progress or external industry plans would be really useful. There's not much information that appears in a search.

    Thanks in advance,

    PS. You're right - I was an engineer in the past ๐Ÿ˜Š

    [Edited to correct numbers]
    Last edited by DeLory; 05-04-22 at 18:23.
  • 37 Replies

  • Best Answer

    DebF_EONNext's Avatar
    Community Team
    Best Answer
    Hey @DeLory what an insightful thread! I've only just come across it again or I would have commented sooner.


    I have great news...we can now install 3 phase smart meters here at E.ON Next and even better it's free to upgrade to smart!

    We have specially trained technicians now who are able to install these - just get in touch with our energy specialists and they will help you get this booked in ๐Ÿ˜„ You can find all of our contact information on this thread: How to contact E.ON Next
    Last edited by DebF_EONNext; 23-05-24 at 17:37.
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  • theunknowntech's Avatar
    Level 79
    Hi @DeLory,

    That's a pretty interesting read you've got there. I'm theunknowntech by the way, a forum volunteer on here. Some say I'm an apprentice of the legendary Blastoise186, and that if I weren't a human, I'd be a health and safety sign! All we know is, I'm definitely a human and Blastoise186 is well... A Blastoise! We both also happen to know at least one or two engineers as well.

    There are only a handful of suppliers currently capable of doing Three-Phase installs and the one me and Blastoise186 are on (OVO) is one of them, albeit still in a trial phase. One of the only Three-Phase S2 Smart Meters currently on the market would be the Aclara SGM1430 Series because most other manufacturers have either not created one yet (cough, cough, L+G) or only have one that's SMETS1, like Secure.

    I'll send this to Blastoise actually, as he might find it interesting as well.

    Thanks for stopping by!
    Just another guy passing by... The unknown tech way...
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  • DebF_EONNext's Avatar
    Community Team
    Hey @DeLory,

    I'm Deb one of the community co-ordinators here on the forum nice to meet you ๐Ÿ‘‹

    We have actually started fitting 3 phase smart meters here at E.ON Next however only in certain areas ๐Ÿ˜ƒ We don't have many engineers capable of this yet so we are still quite restricted, however with continued training & hiring we will be hoping to roll this out further. If this is something you are interested in you could pop our digi team a message through social media & they would be more than happy to check your eligibility to see if it's available in your area yet! Good luck, do let us know how you get on.

    Deb ๐ŸŒป
  • DeLory's Avatar
    Level 1
    Thanks @theunknowntech, I tried to make it interesting and accessible.

    Yes I've seen the posts on 3-phase smart meters on the OVO forums - they're very useful.

    Also thanks for reminding me that, of course, the technical expertise in fitting has to be trained up or hired in, as well as the whole infrastructure behind that of diary management, warehousing and maintenance systems. I recently had to have my distribution board upgraded to increase capacity and it took the whole day for the technician to change it over, test it and complete the condition report. I spent most of that day without power.

    I'm surprised that there's so few SMETS2 3-phase smart meters available in the UK. Is this due to having to certify them? I'm guessing that there may also be issues around limited supply of semiconductors like the car makers are experiencing.

    Cheers for your continued help and advice
  • DeLory's Avatar
    Level 1
    Thanks Deb,

    Yes I just found out that you are starting to fit 3-phase smart meters.

    Please add me to the list of interested people

  • Max's Avatar
    Level 1

    I have a 3 Phase installation with solar panels as well. The issue has always been that standard 3 phase meters in the UK do NOT provide a net sum of usage across the three phases. This means that I still get charged for using power on one phase despite sending back to the grid more than that amount on the other phases.

    So how can I find out which 3 phase meters EON Next are installing and if they are net sum compliant as they should be? I tried messaging through your social media links but no responses.

  • DeLory's Avatar
    Level 1

    So how can I find out which 3 phase meters EON Next are installing and if they are net sum compliant as they should be? I tried messaging through your social media links but no responses.

    Well this is the key question @Max, but since such meters must already exist in the world then the net sum compliant software must also exist. I guess it's then about non-metering aspects: meter certification for the UK network, scaling up production from the meter manufacturers, and hiring, training and managing the electricians to do the fitting.

    Anything further to add @DebF_EONNext?
  • Max's Avatar
    Level 1
    Well this is the key question @Max, but since such meters must already exist in the world then the net sum compliant software must also exist. I guess it's then about non-metering aspects: meter certification for the UK network, scaling up production from the meter manufacturers, and hiring, training and managing the electricians to do the fitting.
    Anything further to add @DebF_EONNext?

    Sorry Delory but that is a really poor response.... EON.next are already rolling out 3 phase smart meters and you have not answered with a single piece of information.

    Of course net sum complaint software exists, 3 phase meters have been able to do it since the 1990s but the energy suppliers choose not to have it enabled when they order their meters. It is now however mandatory under the regulations but that does not mean it is happening in practice.

    I have also spent over 1 week trying to get the answer through EON.next social media with nothing but "please wait whilst we find out replies"

    So the questions remain:

    1) Which 3 phase smart meters are EON.Next installing?
    2) Are they net sum complaint?

    Better still please provide me with contact details of the metering team responsible so I can ask directly (for clarity that is not the phone #/email to request a smart meter as those people are just appointment makers)

    I find it incredible that nobody seesm to be able to answer what is a very simple question.
  • DebF_EONNext's Avatar
    Community Team
    Hey Max,

    Sorry for the delay in getting back to you, the community isn't manned 24/7 so there might not always be a community co-ordinator on hand to help so you may not get a response straight away, you might find it quicker contacting our social media team if you can't find the answer you are looking for on the community already.

    This is an interesting question Max and in all honesty I don't know the answer! I'm not part of the engineering or metering teams but I can certainly try to find out this information for you ๐Ÿ˜ƒ

    Deb ๐ŸŒป