Solar panels, Solax App seems to be wrong!

Sunshinewarrior

The App shows that I am exporting solar energy to the grid, even when the battery has plenty of storage space and the house is drawing very little. It's only small amounts but it happens quite often so must mount up. Solax don't answer my questions and neither does the energy provider. So my question is; why should I be exporting anything to the grid, when there isn't a surplus. Sometimes at night when the battery is full, it easily handles the houses needs but still exports small amounts to the grid. This is my generated energy which they do purchase when there is a surplus by way of a feed in tariff, but of course much more cheaply than the price I pay for energy when I need it. Am I and others like me subsidising the grid?           

gefnew

i would post this here.
https://forums.moneysavingexpert.com/categories/green-ethical-moneysaving

badmemory

Can you see what else is happening around that time.  Is it happening around the time that something is switching off & hopefully only exporting very small amounts like 0.1 kWh.  I have noticed that when I have used my kettle & it switches off (so down from 3kWh to zero) it seems to upset it & for a very short time export a small amount when really it shouldn't.

Alnat1

The figures on the various solar apps are not precise as they are only being measured by a clamp on the wire near you meter. Right now my Lux solar app says export is 0W, my IHD says 9W and the Octopus mini says 12W. If these are the kind of small differences you are seeing, it's hardly worth worrying about. I do prefer that, in my case, a few watts are usually being exported, if it was constantly a little bit of import I'd be paying for it.

Just to show an example of how far out the stats can be, my generation meter shows a total of 15,182kWh since install 3 years ago, the Lux app is only showing 12,974kWh. I'm guessing the generation meter is more accurate?

Qyburn

Sunshinewarrior said:

So my question is; why should I be exporting anything to the grid, when there isn't a surplus. Sometimes at night when the battery is full, it easily handles the houses needs but still exports small amounts to the grid.           

The answer is because inverter and battery control is imperfect.

Consider, the grid connection, the inverter and your house loads are in parallel. And your house loads will be subject to sudden changes.

The inverter is trying to feed just exactly enough power to feed the house without exporting or importing. It has no way to anticipate exactly when a cooker etc will be switched on or off.  The only thing it can do is monitor the grid connection for current flow in or out, and adjust its output to try and cancel that out.

Sunshinewarrior

Thanks for getting back to me and I'm sorry about the delay in my reply, took my wife and son away for a half term break. During the day it's generally around 44 w going to the grid when the battery is only half full so nothing should go to the grid. But I also noticed that late in the evening when the battery is handling the load I still export to the grid around the same amount - but it's not consistent. To give me peace of mind does anyone know of a company who could check out what's going on - maybe I could give them access to the SolaX App I use. Just think it looks wrong and fueling this is EDF ignoring my emails and not calling me back.   

QrizB

As Qyburn says above, this is likely to be due to the Solax inverter not being set up to accurately sense zero current in your meter tails.

Speak to your solar installer. They should be able to access the Solax configuration menus and adjust the zero offset on the current clamp.

If your installer has gone bust or is uncooperative, you might be able to find the relevant inverter manual and default installer password online.

This is nothing to do with EDF, unless they were your solar installer. Solax might be willing to help you adjust the inverter but really it's for your installer to fix.

debitcardmayhem

44W is nothing, over what time frame? My inverter ,not Solax, will balance the load, supplying it from the grid or from the battery, if the load drops then the difference goes the grid if the battery is discharging and generally i. 10-20 seconds later it will ask the battery to drop its output. The mechanism is not instantaneous hence it appears “wrong”. Of course I could be wrong or not describing it very well. 🙁

QrizB

debitcardmayhem said:

44W is nothing, over what time frame?

44 watts continuously is about a kilowatt-hour a day, which is worth investigating and reducing.

It should be possible to reduce it down to single-figure watts.

debitcardmayhem

QrizB said:

debitcardmayhem said:

44W is nothing, over what time frame?

44 watts continuously is about a kilowatt-hour a day, which is worth investigating and reducing.

It should be possible to reduce it down to single-figure watts.

The op hasn’t said it’s continuous though.

badmemory

Mine tends to flick from 25 or 57 watt output to around 50 input to zero, which is what it should be.  That is according to the IHD  With similar but definitely different on the solar monitor.