Skip to main content
R
Rank 2
ruralCTsupply
Rank 2
February 20, 2023
Solved

What smart meter options do OVO offer for polyphase CT metered supplies rated at 200A per phase?

  • February 20, 2023
  • 36 replies
  • 2295 views

Hi,

I have looked at this these threads in the past and always found them detailed and informative - but this is the first time i have put my head above the parapet to ask a question, so apologies in advance if this has been well covered previously. 

*

I live in south of the UK in a rural location and my property has a split (2) phase electricity supply rated at 200A per phase and is currently metered by a Elster A1140 CT meter.  

The meter is modern but operates in single tariff “dumb” mode so requires periodic manual meter readings to be taken.

I am keen to access a wider range of modern electricity tariffs but getting a meter that can facilitate this seems a bit of a challenge.  I have been told that SMETS2 meters (even polyphase ones) seem to only go to 100A per phase so they aren’t an option.  

Most Domestic Electricty supply companies I discuss this with are unable to offer any other options.  Some Business Electricity Suppliers have indicated that our set up is more common on the Commercial side of things and an AMR meeting solution might be appropriate but the Domestic suppliers I speak to seem unable to help with this - even if AMR meters are offered by the Business side of their operations.

*

What meter solutions could Ovo offer in this context?  Can you offer “smart” (not necessarily SMETS2) meters for existing CT metered polyphase supplies rated at 200A per phase that would provide access to wider range of tariffs than single rate variable tariff?

*

Motivation for all of this is since moving in a few year back i have replaced the old oil based heating system with a ground source heat pump, and added a PV solar array too.  Having electrified much of our energy usage I am keen have access to more useful and efficient electricity tariffs and to be able to easily sell excess power from the PV array back to the grid. 

*

Our annual power consumption approx 40,000 kWh per year (largely driven by ground source heat pump system). 

 

Best answer by Emmanuelle_OVO

Updated on 13/03/25 by Ben_OVO:

 

Hey,

 

I got an update from one of our smart meter experts: 

There isn't a Smart solution for CT meters.. it doesn't exist... they must have Automatic Meter Read (AMR). There is confusion about what 'types' of AMR, but all AMR meters are configurable to record export.. (they're technically a Half Hourly meter that's programmed to be read Non Half Hourly) - so they can record the 4 quadrants of energy and present them (import, export, import lag and export lag).

 

Do we support that, I highly doubt it, as we don't support AMR itself very well. All suppliers are required to support it for their domestic CT customers, the licence states that very clearly, it's part of the Smart roll out obligation, that any domestic customer with a CT supply must have a AMR capable meter by a set date and report that to Ofgem.

 

But it must be CAPABLE to providing remote readings (AMR means Automated Meter Reading) but it depends on the communications solution in place.. as sometimes it's not possible to get reads remotely.. this is causing confusion with the RCAMR an RCAMY..

 

*NC stands for Non configurable Remotely (of course!!) where as RC stands for Remotely configurable.. can be done by comms signal.. doesn't need a site visit*

 

The RCAMR and RCAMY bit relates to if they can be remotely enabled or not, to provide reads, but NONE of the descriptions means they are communicating, just that they are all capable of doing so, but need to be connected to a communication solution, be that a telephone line or cellular solution whereas Smart should always communicate..

 

AMR meters are only really one way, they send reads, that's it, nothing else that smart does.

36 replies

Show previous replies
Tim_OVO
OVO Staff
Tim_OVO
OVO Forum Legend
February 23, 2023

One further question for the expertise of this forum is a bit more Out There.

 

Next to our main 200A split phase CT supply (literally 1 metre away) we have a second metered supply that is single phase 100A.  this second supply has separate mpan etc and is normal sized supply for normal small/medium sized residential property.  this supply DOES have a SMETS2 meter that happily transmits usage data to supplier over the SMETS2 WAN (via a connected T2 boosting aerial) and I can get access to all Octopus’s TOU tariffs for it.  The demand from this supply is v small, approx 9kWh per day in the winter and <2kWh per day in the spring/summer/autumn.

 

The Out There question is does anyone here have any idea whether it would be possible to add a diverter or manager some sort after my Solar Edge pv inverters that could send the electricity generated by the PV array to the main supply (as it does at present) when there was demand from the main supply and but when that demand had been satisfied could send any excess generated electricity back to the grid via the SMETS2 meter?

 

It sounds a bit whacky to me but if this was possible I could possibly self consume as much as possible via the Main CT supply and export the PV generated electricity via the SMETS2 meter?

 

I think @ArundaleP might be able to answer this one…

 

What is the difference between "CT, polyphase or otherwise" and a regular 2 or 3 phase supply that can support a SMETS2 3 phase meter? 

 

@Jeffus according to auroro energy: 

 

CT (Current Transformer) meters are installed on any connections with a load greater than 100 Amps. They measure a fraction of the amps (current) passing through the connection and a multiplier is applied to this reading to reflect the actual amps.

Carbon neutral - we need a community to get there! My green tech: Aclara SGM 1411-B smart meter, Chameleon IHD6
    Jeffus
    Rank 20
    Jeffus
    Rank 20
    February 23, 2023

     

    What is the difference between "CT, polyphase or otherwise" and a regular 2 or 3 phase supply that can support a SMETS2 3 phase meter? 

     

    @Jeffus according to auroro energy: 

     

    CT (Current Transformer) meters are installed on any connections with a load greater than 100 Amps. They measure a fraction of the amps (current) passing through the connection and a multiplier is applied to this reading to reflect the actual amps.

     

    @Tim_OVO so if @ruralCTsupply can get his load below 100a per phase they don't need one of these CT meters and can have one of OVOs regular 3 phase SMETS2 meters? 

    Blastoise186
    Super User
    Blastoise186Super User
    Super User
    February 23, 2023

    If my understanding of that is correct… An example 200A of Peak Usage could be served quite easily by normal 3-Phase?

    Securing energy by zapping security bugs... For that is The Blastoise Way! Remember, I'm just like you - AI Powered Evil Geniuses aren't Staff!
      Jeffus
      Rank 20
      Jeffus
      Rank 20
      February 23, 2023

      If my understanding of that is correct… An example 200A of Peak Usage could be served quite easily by normal 3-Phase?

      I thought that was how it worked, but i am no expert

      I think @ruralCTsupply is going to try and get an electrician to  put  in some monitoring to see what the actual peak load is on the property which might help with options. Whether they have close to a peak 200a load for each of the current two phases. 

       

      BPLightlog
      Super User
      BPLightlogSuper User
      Super User
      February 23, 2023

      ….

       

      The Out There question is does anyone here have any idea whether it would be possible to add a diverter or manager some sort after my Solar Edge pv inverters that could send the electricity generated by the PV array to the main supply (as it does at present) when there was demand from the main supply and but when that demand had been satisfied could send any excess generated electricity back to the grid via the SMETS2 meter?

       

      It sounds a bit whacky to me but if this was possible I could possibly self consume as much as possible via the Main CT supply and export the PV generated electricity via the SMETS2 meter?

      Your solar edge inverter should have settings that prioritise demand as you want;

      1 - house (or specific feed if connected via)

      2 - energy storage (if fitted)

      3 - feed to grid

      You would need to ensure that the DNO were ok with any extra grid feed if on a specific leg of the supply. Sounds like that’s already in place but worth checking

      What would be difficult (can’t think of a way) would be to couple this across feeds

      Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}
        R
        Rank 2
        ruralCTsupplyAuthor
        Rank 2
        February 23, 2023

        if it turns out to be possible to get the supply down to 100A per phase but remain split phase that might be a realistic option.  

        3 phase 100A per phase would be closer to our current set up but the issue with changing to a 3 phase is the installation of the additional overhead power line from the nearest sub station capable of offering the 3rd phase. I have understood previously from DNO that this is potentially 7miles of new overhead line required and would be through national park, site of special scientific interest, conservation area etc.  The stake holders that would be concerned about any digging or new over head lines are considerable.  The distance would make it costly (low to mid six figure cost was quoted by DNO) and the location considerations means that it might not even be possible.   The cost alone means that even i i decided i could afford it it makes little sense economically to spend hundreds of thousands on a 3rd phase to be able to get a SMETS2 meter, as, everything else being equal, savings might mean payback of 3rd phase cost would probably be well over a 100 years.

         

        discussions with Octopus aren’t quite dead yet.  They do seem to be able offer some export opportunities with AMR meters for their business customers, which if the case would at least allow me to sell excess pv kWh at a reasonable rate.  

        https://octopus.energy/blog/panel-power/

        But this seems unlikely to help with access to Time Of Use tariffs (although if turns out is possible for them to install an suitable AMR meter that provide half hourly (or more freq) readings perhaps I can convince them they have all they need to offer me TOU tariffs too - seems a bit of a stretch).

        I spoke to helpful chap at Ocotpus yesterday who seemed to think that (when configured properly) our current meter (Elster A1140 in CT mode) should be fine for export measurement (possibly even with manual reading submission).  He seemed to think was just a case of getting the request in front of the right team, Having been burnt in the past I am not getting hopes up yet though.

         

         

          Blastoise186
          Super User
          Blastoise186Super User
          Super User
          February 23, 2023

          But you can’t be a Business customer on a Domestic supply. And there’s no price protections for Non-Domestic supplies like there are for Domestic… And it costs 5 million percent more to run that way! :(

          Securing energy by zapping security bugs... For that is The Blastoise Way! Remember, I'm just like you - AI Powered Evil Geniuses aren't Staff!
          Jeffus
          Rank 20
          Jeffus
          Rank 20
          February 23, 2023

          But you can’t be a Business customer on a Domestic supply. And there’s no price protections for Non-Domestic supplies like there are for Domestic… And it costs 5 million percent more to run that way! :(

          I think what Octopus are saying is that they can possibly let @ruralCTsupply stay on the current domestic import tariff (non ToU) , but make use of a business export tariff if the right people agree. 

          That way they get the price protection for their usage.

          In fact the SEG Smart Export Guarantee isn't limited to domestic customers.

          Also you don't even need a smart meter to get the SEG. You can simply have a half hour export meter. 

          Would a separate export meter work with the current meter? That would solve the export issue so you didn't need to divert the excess solar to the single phase supply. Or doesn't that work as it is a 200a 3 phase supply? 

           

           

           

          BPLightlog
          Super User
          BPLightlogSuper User
          Super User
          February 23, 2023

          The original question relates to accessing various tariffs alongside selling excess PV back. It’s the more flexible tariffs that would need a smart meter

          Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}
            R
            Rank 2
            ruralCTsupplyAuthor
            Rank 2
            February 7, 2024

            Hi All, 

             
            Following on from the conversation almost a year ago my existing supplier did propose a partial solution.  
             
            They proposed adjusting the configuration of my current AMR CT meter to enable an Export register so the meter would be able to provide realigns for both Import and Export levels of electricity, and I would then periodically manually submit Import and Export meter readings to them - as I already do for Import.  Instead of the reconfiguration they also suggested it might be easier to just replace the exciting AMR CT with a new one that they and their MOP were more familiar with - this would be determined by an on site engineer visit.  
             
            This solution wouldn’t allow me access to Time of Use tariffs (I see there has been some discussion on this site about Half Hourly AMR readings not being able to be integrated into SMETS based Time Of Use tariff systems) but would allow me join an export tariff and get paid for the electricity we export.
             
            I followed up with the supplier over the subsequent months, but having made the proposal they seemed un able to actually deliver it and arrange the necessary engineer visits to do the required work (i.e. reconfigure or replace the meter).  Eventually in September contact from the supplier on the issue dwindled off, and when I finally got their attention again in the Autumn they seemed to have little recollection of the previous proposal and not much knowledge about the situation at all.  
             
            Having continue to follow up with them  the supplier now seems to have zero knowledge of their previous proposal or of any previous discussions about the issue.  Through choice or lack of corporate memory they seem to have no knowledge of anything that has gone before with regard to this issue and are now telling me that they only offer export tariffs (including SEG) to customers with smart meters (irrespective of info on their website that suggests different or they have told me in the past).
             
            I am still trying to follow up with them but it seems an increasingly lost cause which is particularly frustrating as last summer,  according to my solar and battery management technology, we exported a considerable amount of excess pv generated kWh to the grid for free (our ground source heat pumps being mostly off for the summer and the solar array still belting out the kWhs).
             
            As a result of this latest disappointment from our current supplier I am looking at whether other suppliers might be able to help?  
             
            Does anyone here know if OVO would be able (and willing) to provide the sort of solution outlined above?  Could OVO provide an AMR CT meter (or reconfigure the existing one) that can measure export (and import?) electricity to allow participation in an export tariff where I could submit manual readings?  If this is possible it makes little sense to have import and export with different suppliers so I would probably look to switch import suppliers too.
             
            Not sure if this is one for the public forum or not so if someone what to message me on the side about this I would be more than happy to discuss further.
             
            Let me know what you think.
             
            Thanks.


             

            Show more replies
            Terms & ConditionsAccessibility statement

            OVO Energy Ltd, Floor 5, Crescent, Temple Back, Redcliffe, BS1 6EZ, (Company no. 06890795) registered in England and Wales.

            OVO (S) Gas Limited is registered in England and Wales (Company No. 02716495) at Floor 5, Crescent, Temple Back, Redcliffe, BS1 6EZ.

            OVO (S) Gas Limited is part of OVO Group Ltd