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The import readings on my Secure Liberty S1 meter don't match the energy purchased figure on my Solar PV and Home Energy Inverter - Which figure is correct?

  • 12 October 2021
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Updated on 14/12/23 by Emmanuelle_OVO: - Note that this discussion originated on our Secure Liberty 100 Smart Meter guide topic

 

Hi Tim,

 

Can you please confirm if the Historical data shown should match to the import readings?

 

For instance the historical data says I used 600kwh for September and the import readings say I used 800kwh.  Should these figures match?  If not, why not?

 

Thanks,

Joe

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Best answer by Transparent 13 October 2021, 10:40

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Hi @Mbu1982  and welcome :slight_smile:

From where are you getting these two different readings?

  • the meter itself
  • your online usage page
  • the OVO App
  • a bill

Do you have a SMETS1 Smart Meter, and is that why you’ve arrived on this particular topic?

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From the meter itself. The monthly usage over 12 months is significantly lower than what the import readings are giving.

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Are saying @Mbu1982  that both readings are being taken from the same (electricity) Smart Meter?

1: Which manufacturer/model?

2: Was it installed by OVO or acquired by them at a later date?

3: Has it now been migrated to the National Smart Meter Network, or don’t you know?

Please don’t worry about using the correct technical language. Just tell us what you’re observing and we’ll sort it out from there! :slight_smile:

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It is the secure Liberty 100.  The same one as the original guide. This is a general enquiry as I am looking at coming over to OVO but I am in the middle of a dispute with my current provider.  
 

It should be on the smart meter network.

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Thanks @Mbu1982  - there’s no problem about you not being an OVO customer (yet). Many members of the Forum are actually with other Energy Suppliers.

 

2: The way in which the Switching Process operates means that you don’t have to resolve everything before moving away from a Supplier with whom you’re in dispute.

But if you intend switching before the end of your contract date, then make sure that you’ve implemented their Complaints Procedure. If you want to discuss this further, then first read the (new) Tutorial about Switching to OVO and then add your comment/question there (not in this topic).

 

3: A SMETS1 Smart Meter will initially have operated on a proprietary network organised or owned by the Supplier who installed the meter.

They are gradually being moved across the National Smart Meter Network. That’s why I asked if you knew whether your particular meter had been migrated yet. But we can help resolve this if it turns out not to be the case.

 

4: Please confirm for me… are both of the usage figures you gave (600kWh and 800kWh) obtained from the display on the front of the same Liberty 100 meter?

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Yes, when I press 4 it gives me the historical usage. When I press 9 it gives me the import readings. The calculated kWh usage calculated from the import readings is much higher. 

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Thanks for clarifying this @Mbu1982 

I assume you are being billed for the 600kWh figure, rather than the 800kWh which is labelled as ‘Import’?

The Import and Export registers would normally be used for a site which is both generating and drawing electricity from the Grid as part of a renewable-energy system. A typical example would be a house with both PV Solar Panels and a Storage Battery.

Unless you are with a Supplier who uses those registers to monitor energy flow, I doubt that they have been configured. As such the readings are arbitrary.

Nevertheless I haven’t got 1st hand experience of the Secure Liberty meter, so I’m also going to tag @Blastoise186 and ask him to respond briefly.

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The plot thickens…. I am being billed for the 800kWh labelled as import. You have guessed it completely right. My troubles started with the installation of my Solar PV and battery storage system.  The usage calculated from the import readings is around 1000kWh more than the history consumption readings taken from the same meter. My solar usage readings are over 2000 kWh usage less than the import readings. Instead of my cheap bills getting even cheaper, they have risen dramatically.

 

They installed a check meter into my property and that gave the same usage as the import readings but still different from the historical data readings. 
 

I hope this makes sense?

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Oh dear!

This situation is more complex than it first appears, isn’t it @Mbu1982 ? :scream:

Let’s stick with the subject of this topic for the moment and ask the Moderators, @Jess_OVO and @Tim_OVO to find someone who can provide an answer about the Secure Liberty SMETS1 Meter and the figures obtained from buttons 4 & 9.

Once I understand that, I may ask us to move to a different topic to discuss the practical matters of the Solar Panels and your Storage Battery. We need to have that discussion in an area where we can draw on insight from others. They won’t find us here in a topic about Secure meters!

 

In the meantime could you do two things:

1: Complete your Forum Profile page. That’s where we look for essential background information such as your area of the country and whether you also have an Electric Vehicle.

When you’re asked “When did you join OVO” you can make up an answer. “Next year” would be appropriate :hugging:

And find something equally light-hearted for the question about which Plan you’re on!

 

2: Have a look through the topic Photovoltaic Solar Panel Installation to make sure you understand the basic information that’s already been offered by existing members here.

 

Finally, please note that I’m a participant on the current OVO Battery Storage Trial. However, most of the technical material is not on the open/public part of the Forum. Nevertheless we can go as deep down that technical hole as you wish!

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Hi @Mbu1982 and welcome to the OVO online community,

 

I see you’ve already met our community Plan Zero Hero, @Transparent whose done some brilliant trouble-shooting into what could be behind the discrepancies you’ve noticed when checking your monthly usage on your Secure Liberty smart meter.

 

I handily do have access to the user-manual for this meter and have discovered the expected information that should be shown on the meter.

 

In terms of the import reading - this is the viewed by pressing the ‘9’ button if you’re on a single rate plan or ‘6’ for dual-register meters. This is the reading that should be used on any suppliers billing (and we do always advise checking that your smart meter is communicating the readings consistently and your billing is based on actual smart readings rather than estimated readings)

 

The historical usage data view is accessed by pressing ‘4’, as you’ve already discovered. This will allow you to scroll back through the usage figures for the last 12 months starting with the last completed month (for example were you to check this now the first months data available would be the month of September). 

 

We’re obviously not in a position to comment on another suppliers billing process but here at OVO your billing schedule may not necessarily align with a calendar month - we produce our monthly summaries for our members around the same date each month but this may be at any point in the month, so I wonder if this could explain the discrepancies you’ve spotted.

 

It’s also worth mentioning that any suspected meter issues should be raised directly to your supplier, they’re responsible for maintaining or replacing your meter if it’s found to be faulty.

 

Hope this helps get to the bottom of things - do keep us updated, we’re always happy to offer advice here where we can.

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Hi Jess and thanks for the reply.

 

My issue still remains based on total usage.  Surely my total usage for the last year should be pretty much on point?  The start read from the import reading till the month end should be the same as the total of my historical data.  As I have only just passed 12 months with Avro.

I would also expect my inverter readings to match but it seems to me like I am being charged for the energy my panels are generating.

 

I appreciate the help from you all, even though I am not yet an OVO customer.

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We’re always happy to help out OVO members and potential OVO members alike, @Mbu1982 :slight_smile:

 

 

My issue still remains based on total usage.  Surely my total usage for the last year should be pretty much on point?  The start read from the import reading till the month end should be the same as the total of my historical data.  As I have only just passed 12 months with Avro.
 

I’d say this might not always be the case. It would of course depend on when the smart meters were installed and what the install reading was, as this may not necessarily be 00000 depending on whether a brand new meter or a refurbed meter was used (I know - it surprised me to learn this too!)

 


I would also expect my inverter readings to match but it seems to me like I am being charged for the energy my panels are generating.

 

 I’m going to have to confess, inverter readings aren’t my area of expertise! ( @Transparent is our community expert on all things Home storage) Whilst I know incorrectly wired Solar panels may cause a meter to clock backwards, I’ve not heard of the opposite happening before, although it might be worth checking in with the Solar panel installers if you are concerned this might be the issue.

 

Hoping this information helps in some way - do pop back to keep us updated - it’ll be really helpful to others who might be facing similar issues when setting up their own micro-generation and Home storage system. 

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Let’s pick off just one point and try to make sense of it. We can then come back to the wider issue.

@Mbu1982  wrote:

I would also expect my inverter readings to match but it seems to me like I am being charged for the energy my panels are generating.

There may seem to be a resemblance between those figures but I don’t see how it can possibly be the case.

You have both a PV Inverter and a Storage Battery. These are two devices which will have received G99 approval from your Distribution Network Operator (DNO) and should have separate metering. How could the export to the Grid from the PV Inverter be ‘known’ to your SMETS1 Meter?

Your Energy Supplier can only ‘see’ data retrieved from your Smart Meter. They have no way to view export data from your Inverter, and nor does the Meter.

 

Here’s the physical arrangement at my own house for comparison.

The Growatt Inverter has inbuilt metering and has therefore not been installed with a separate Export Meter.

The PowerVault Storage Battery has no ‘live metering’ display and therefore connects to my Consumer Unit via the OB Export Meter to the left.

Both the Growatt and the OB Export Meter have terminals to allow data to be retrieved. However these remain unconnected. My Smart Meter only ‘knows’ the combined effect of both devices.

 

Are you happy with this explanation?

Or do you believe that Avro have visibility of your PV export by some means?

 

Aside: I am working on a project to install my own data monitoring for my Growatt and the OB Export Meter. But OVO could still not retrieve this. Further information will appear later on the topic about Energy Monitoring.

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Thanks for the reply.  The reason I asked about my inverter is that it seems to read my energy that I purchased.  Essentially my solar system is my main feed for energy and if I need more it comes from my battery and finally the grid.  My inverter displays this as my yearly energy purchased: 

Why would this be wrong?

I dont expect my Smets1 meter to know my export, but I do expect my import readings to be very similar to my inverter.  I have called Solis customer care directly and they do not understand why there would be a difference?

Thanks,

Joe 

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The reason I asked about my inverter is that it seems to read my energy that I purchased.

It may be able to achieve this.

Has it got a current sensor connected to it?

 

I dont expect my Smets1 meter to know my export, but I do expect my import readings to be very similar to my inverter.

Your SMETS1 Meter should ‘know’ both your import and export from the house. But it won’t know how much you’ve stored or used within the home.

Why do you expect the readings from the Inverter to be similar to any registered by the Meter? (and I think you’ve transposed ‘import’ and ‘export’ in the sentence I’ve just quoted)

Everything you’re writing is reasonable. Just keep telling us the facts and we’ll try to understand what’s happening.

There isn’t really any such concept as a customer who’s mistaken about energy usage. The proper description for that issue is “a failure of the installer and documentation to adequately describe the system!

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Thanks for responding,  I am trying to get this clear in my head. 

 

Correct me if I am wrong, I am now taking my inverter as the first point of call for organising my usage.  If my solar system does not generate enough energy for me to use, that extra is then purchased from the grid?  The inverter  and system seems to tell me exactly what is currently being generated and what is being used? See below: 

 

Why would the energy purchased be different to my SMETS1?  As I believe the inverter is the gatekeeper as to how my system operates…...

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I think we’re all trying to get this clear in our heads @Mbu1982  :slight_smile:

How is the data in that chart obtained?

Does the manufacturer of your Storage Battery and your PV Inverter collect that data and display it online (or in an App)?

Where do they get the Energy Purchase figures from?

It may not be a current-clamp. There are alternative methods.

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The data is taken\stored directly on the inverter.  I can then access the information online/app.

 

The energy purchased figures are taken from the inverter, as it shows what I am generating, what my consumption is and what I need from the grid to make up the difference.  Example below:

 

I have even reached out to Solis and they say the information should be accurate as the inverter is the gate keeper to my system.  It knows what is being generated, battery level and what my home use.  I dont know why everything does not match up?

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This is getting somewhat tricky to answer without knowing the hardware you’ve had installed.

I’ve looked through the (Chinese) website for Solis and worked out that you probably have a RHI-3.6k-48ES Inverter. The ‘3.6’ may be a different number, but the operation will be the same.

Does it look like this?

If so, then it should have a separate Lithium-Ion battery pack and a wall-mounted meter.

The meter connects to the Inverter with a data cable and should also have another cable to a current-clamp on your mains incomer to the house. Here’s the connection diagram from the Solis Installation Manual

Can you confirm that this is the equipment you have and that there is a current-clamp connecting to the terminals at bottom-left of the meter?

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I can’t say 100% but this is my setup:

 

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That looks like a quality installation @Mbu1982 

For the benefit of others who come to read this in future we should let the Moderators decide whether to move this discussion across to the topic about Photovoltaic Panels. That enables other members to find it.

The one item you haven’t provided a picture for is the Generation Meter. Do you know where that is?

I assume there must be one present because the red glow-stick(!) at bottom right of the Solis inverter is a radio-link to it :slight_smile:

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I do believe this discussion has a link to both topics. I am querying this based on a discrepancy between my smart meter import reading, monthly consumption and my solar POV system

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Great. That’s the meter we’re looking for.

There should be lead from it which goes to a clamp on one of the two thick wires between your Smart meter and the Consumer unit with the trips in.

When you find the clamp you should be able to see an arrow (or two), either printed on or embossed into the plastic. We need to know if the arrow points towards or away from the Smart meter.

 

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Morning, I have found the clamp but it has no arrows on it….

 

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