FIT meter gives strange readings; installer gone bust!

Reed_Richards

Qyburn said:

Reed_Richards said:

To repeat myself, if it is a bidirectional meter it doesn't matter which way round it is connected, you just need to know which way round it is connected.   

Let's say I exported 300kWh and imported 100. My meter would show a net of 200. Connected the other way round it would read Export 100, Import 300 and Net -200.

Well I've looked extremely hard at my generation meter, which is tiny in the first place.  And it does say Imp and Exp in very very tiny lettering, something I had never seen before.  What it calls Imp is the export and what it calls Exp is the import and the nett reading is negative (because I export vastly more than I import).  But it is so blindingly obvious what is going on that I can't believe this could ever be a problem.  See which reading increases if you charge the battery overnight and which reading increases during a sunny day.  Take photos if you need proof.

Edit: Also this depends on your frame of reference.  The electricity that comes out of my inverter I import into my house and then some of that I export to the grid.  Likewise some of the electricity that I import into my house from the grid I can export into the battery through the inverter.  So if the frame of reference is my house and I regard the grid and the PV + battery as alternative power sources then the terminology of my meters makes perfect sense.  

matt_drummer

Hi Reed,

I am not sure your set up is correct/complies with the FIT scheme.

Was it originally installed with a hybrid inverter and a battery or have you changed that?

The normal way to add a battery to an existing FIT system is ac coupled.

As far as I am aware, you cannot change anything without permission.

I added battery storage but it's ac coupled.

My FIT generation meter only records the solar generation, nothing else goes through it, that is how it is supposed to be.

I am not an authority on the subject but maybe somebody else here is?

matt_drummer

Reed_Richards said:

Edit: Also this depends on your frame of reference.  The electricity that comes out of my inverter I import into my house and then some of that I export to the grid.  Likewise some of the electricity that I import into my house from the grid I can export into the battery through the inverter.  So if the frame of reference is my house and I regard the grid and the PV + battery as alternative power sources then the terminology of my meters makes perfect sense.  

It probably does.

But, I don't think you are allowed to do that under the FIT rules.

You can't touch it, you can't change panels and you can't change inverter type without permission.

And I don't think you can add dc coupled batteries and use net metering.

That is my understanding of the rules.

Reed_Richards

Fortunately, my system has not been altered since it was installed.  And we are wandering a bit off-topic here; I just wanted to indicate that a negative reading on an export meter was perfectly feasible, even logical if you regard the house as your frame of reference.    

matt_drummer

Reed_Richards said:

Fortunately, my system has not been altered since it was installed.  And we are wandering a bit off-topic here; I just wanted to indicate that a negative reading on an export meter was perfectly feasible, even logical if you regard the house as your frame of reference.    

I don't think so.

The OP has what looks like net metering.

What happens in December, for example, when you import more than you export.

Where does the generation figure come from?

Presumably, what you have generated plus what the battery has supplied minus what you have imported and then plus/minus any battery losses?

The OP seems to be doing the same except that they have added a battery later.

The generation meter is supposed to be just that, a meter that records what has been generated, not a composite of imports and exports.

Qyburn

My read of guidance etc is that where you have what OFGEM call "colocated storage", then the generation meter needs to report a net reading, ie subtracting anything drawn from the grid, from the energy produced by the installation. That net reading is not expected to be negative, as we see from the OP, and from OFGEM ...

"FIT installation owners considering installing a “bi-directional meter(s)” should note that FIT meter readings taken using such meters will be calculated by the meter on the difference between each month’s import and export readings. This differs from the meter readings taken by standard meters, which measure and record the generation and/or export of the FIT installation on a cumulative basis. If the difference between import and export in one month is negative, zero FITs payments could be claimed."

I still think he just has the meter connected the wrong way round.

Reed_Richards

Qyburn said:

I still think he just has the meter connected the wrong way round.

And I still think that, provided the OP has the right sort of meter, then whichever way round the meter is connected has no adverse consequence.  One way round you get a positive number, the other way round you get a negative number but it's the same number.

QrizB

matt_drummer said:

The generation meter is supposed to be just that, a meter that records what has been generated, not a composite of imports and exports.

There have been several accounts of people with DC-coupled batteries having "net metering" generation meters, and these being accepted by Ofgem.

I don't see anything fundamentally wrong here, although it would be more convenient ismf the OPs meter had been installed the other way around.

Qyburn

Reed_Richards said:

And I still think that, provided the OP has the right sort of meter, then whichever way round the meter is connected has no adverse consequence.  One way round you get a positive number, the other way round you get a negative number but it's the same number.

The qustion is whether the OP can persuade EON to think this way, given what he says in the first post.  And whether that's going to be easier than fixing the meter so it reads the way it should. When I say "should" I mean the way both EON and OFGEM expect.

Tonychilvers4 said:

In January 2024, I had a battery installed to work with the solar panels I already had (January 2012).  This required a new meter and I have submitted manually the three meter readings required since, to E.On.  They recently asked for a photo of the meter readings to verify my entries and have said that the readings are faulty - one is a negative!  The Nett reading is -3429, which they say is impossible and therefore will not accept readings from me.

Reed_Richards

QrizB said:

There have been several accounts of people with DC-coupled batteries having "net metering" generation meters, and these being accepted by Ofgem.

Are you implying that there is an alternative way of measuring generation if you have a DC-coupled battery?  I can't figure out what it is.