Smart meter incorrect installation caused increased energy usage

[Deleted User]

matt_drummer said:

If their battery is constantly charging and discharging throughout the day it could be bumping up both the import and export.

As the smart separates the import and export the OP could be paying for lots of unneeded import and getting nothing for the export.

Of course, the energy has to go somewhere and I doubt the meter is lying, but what the OP pays for is important and that is what has alerted to them to the problem.

It’s difficult to work out what the system is doing from the information provided. My incorrectly manufactured ct clamps didn't result in me importing any additional electricity but the OP's system may behave differently.

That is a totally different argument but one which I agree with. However, the OP was initially concerned that her smart meter was faulty. I have tried to explain that what she is seeing is normal. There must be a way to select solar charge only for her battery. She can then see how little she is taking from the Grid (kWh) on a sunny day in June.

My figures for yesterday were 42.7kWh of Solar with 28.6kWh of export and zero grid import. The difference was houseload including battery round trip loss. If I switched to battery grid charging, then the solar gain wouldn’t change but the export would increase by 90% of the amount imported from the grid. Whether grid charging is a good idea when it isn’t needed depends on battery size and the difference between import and export costs. (Battery cycling costs are also a consideration). 

matt_drummer

[Deleted User] said:

matt_drummer said:

If their battery is constantly charging and discharging throughout the day it could be bumping up both the import and export.

As the smart separates the import and export the OP could be paying for lots of unneeded import and getting nothing for the export.

Of course, the energy has to go somewhere and I doubt the meter is lying, but what the OP pays for is important and that is what has alerted to them to the problem.

It’s difficult to work out what the system is doing from the information provided. My incorrectly manufactured ct clamps didn't result in me importing any additional electricity but the OP's system may behave differently.

That is a totally different argument but one which I agree with. However, the OP was initially concerned that her smart meter was faulty. I have tried to explain that what she is seeing is normal. There must be a way to select solar charge only for her battery. She can then see how little she is taking from the Grid (kWh) on a sunny day in June.

My figures for yesterday were 42.7kWh of Solar with 28.6kWh of export and zero grid import. The difference was houseload including battery round trip loss. If I switched to battery grid charging, then the solar gain wouldn’t change but the export would increase by 90% of the amount imported from the grid. Whether grid charging is a good idea when it isn’t needed depends on battery size and the difference between import and export costs. (Battery cycling costs are also a consideration). 

Their system isn't functioning correctly, probably due to the incorrect placement of the ct clamp.

They may be able to stop the battery functioning and eliminate from the equation, but who knows?

Do we know what their inverter is?

They could have just swapped the ct clamp around and see what happens, they haven't done that yet as far as we know.

Their solar array may be big enough to cover a lot of their use in the sunnier months, but like you, I doubt their battery is big enough to be of huge benefit throughout the year.

TheElectricCow

It seems like everyone is more or less in agreement that the battery is charging from the grid, so it follows that the this is the most likely cause of the higher than expected import readings, which appears to be what the OP’s main concern is.

Whether this is happening because of the CT clamp or some other factor is difficult to say for certain with the information provided, but the issue did supposedly begin after the new meter installation. It seems a logical conclusion that during the installation the clamp may have been removed from the cable and potentially put back the other way around, so this may well be the reason for the strange readings and/or battery charging behaviour and therefore the increase to import that occurred after meter installation.

[Deleted User]

TheElectricCow said:

It seems like everyone is more or less in agreement that the battery is charging from the grid, so it follows that the this is the most likely cause of the higher than expected import readings, which appears to be what the OP’s main concern is.

Whether this is happening because of the CT clamp or some other factor is difficult to say for certain with the information provided, but the issue did supposedly begin after the new meter installation. It seems a logical conclusion that during the installation the clamp may have been removed from the cable and potentially put back the other way around, so this may well be the reason for the strange readings and/or battery charging behaviour and therefore the increase to import that occurred after meter installation.

As said many pages ago. A faulty analogue meter may also have been a factor but as it is now in a skip/landfill/scap we will never find out.

matt_drummer

I have read many threads and articles here and elsewhere about solar panels and batteries.

Whilst there may be many really good installers, its clear that many of them take little time to explain how the systems work, how they are installed, how to make the most out of them and what to look out for in respect of problems.

The systems are fairly straight forward but they do take a certain amount of engagement and monitoring. They add a level of complexity to a home's energy system that means  problems can occur.

I would urge anybody that has or is considering getting solar panels and batteries to ensure that they take some time to understand how it works, what to expect and when to identify a problem.

chris_n

[Deleted User] said:

chris_n said:

[Deleted User] said:

chris_n said:

Dolor said:

Putting the CT issue to one side for a moment, whether a CT is fitted on not makes no difference to what the smart meter is recording in the way of import and export. As I posted earlier, I still think that OP's confusion is down to an unrealistic expectation of the savings from a very small array and battery, and an old analogue meter that went backwards when electricity was exported. To put the above into context, an array that generates c.3000kWh/year is not going to knock 3000kWh/year off the import bill even with a small battery: probably, close to 2300kWh/year at best.

Yes, the OP could ask for a meter check but I suspect she would be wasting money if she does.

The incorrect CT orientation is more than likely making the battery charge from the grid when there is any load coming into the house, when the load drops below thresholds then the battery will discharge to grid. The manual states flows will be incorrect ( it actually says backfeeding) when the CT is the wrong way round.
The smart meter is only measuring the import (on that register) but that is then going into the battery then discharging to the grid. There is nothing wrong with the smart meter.

Swings and roundabouts. If the battery is charging from the grid then more solar is going to export. In terms of kW there may be a 10% difference,

If the OP was using 10kWh/day last Winter then this equates to 3650kWh/year. (I know slightly less lighting in the summer). The array is small so is the battery so in the round the OP might get 2/3 of import reduced but this not linear.

I still think that the issue here is high expectations of PV solar and an analogue meter that was knocking off units as energy is being exported. The App and CT placement is only an adding to the OP’s confusion. It is a simple matter of reading the meter once a day to see import versus export.

The battery is charging from the grid when the solar is not generating because it is seeing the grid import as solar export. When the solar is generating the battery is exporting to the grid to try and cover the 'import' that it is seeing when the solar is in fact exporting. Reverse the CT then the 'import' becomes export from the solar and the battery charges correctly,  when the solar is not generating the battery will discharge to cover the actual import. 

Energy whether it has come from the grid; solar or battery has to go somewhere. Playing around with CT clamps doesn’t change this basic equation. If the battery is on solar top up only, then fewer units will be exported. Conversely, if the battery is allowed to charge from the grid, then more units will be exported. The other given is there will be at least a 10% round trip loss if a battery is involved.

I can select export ALL on my Powerwall2. The battery will charge from the Grid between 2 and 5am and then discharge to the Grid from 4 to 7pm based on import and export prices. The house will then run on grid until 2am when the battery charges again. If I look at my smart meter, I get both import and export index increases.

Conversely, if I select solar only, my battery charges during the day with solar. Solar goes to the grid when the battery reaches 100% and the battery takes the load when the sun goes down. When I look at my smart meter there is no import but reduced export compared to grid to battery charging.

Bear in mind the OP has a very small array and battery. I have 6.35kWp and a 13.5kWh battery. CT clamps are just a distraction save for the fact that they change the import/export ratio.

You are completely missing the point of what I am saying. One of the clues that I mentioned earlier was the battery was 97% full at something like 6am. 
The CT clamps that controls the battery system is the wrong way round according to the manual, it should point towards the grid. Because it is the wrong way round when the house is importing overnight it sees this as export so charges the battery, as the battery pulls more current the house imports more so the battery charges even more until the battery is full.
When the solar starts the CT sees it as export so starts to discharge the battery to the grid and so on.
There is nothing wrong with the smart meter and the old one was fine too.

chris_n

matt_drummer said:

[Deleted User] said:

matt_drummer said:

If their battery is constantly charging and discharging throughout the day it could be bumping up both the import and export.

As the smart separates the import and export the OP could be paying for lots of unneeded import and getting nothing for the export.

Of course, the energy has to go somewhere and I doubt the meter is lying, but what the OP pays for is important and that is what has alerted to them to the problem.

It’s difficult to work out what the system is doing from the information provided. My incorrectly manufactured ct clamps didn't result in me importing any additional electricity but the OP's system may behave differently.

That is a totally different argument but one which I agree with. However, the OP was initially concerned that her smart meter was faulty. I have tried to explain that what she is seeing is normal. There must be a way to select solar charge only for her battery. She can then see how little she is taking from the Grid (kWh) on a sunny day in June.

My figures for yesterday were 42.7kWh of Solar with 28.6kWh of export and zero grid import. The difference was houseload including battery round trip loss. If I switched to battery grid charging, then the solar gain wouldn’t change but the export would increase by 90% of the amount imported from the grid. Whether grid charging is a good idea when it isn’t needed depends on battery size and the difference between import and export costs. (Battery cycling costs are also a consideration). 

Their system isn't functioning correctly, probably due to the incorrect placement of the ct clamp.

They may be able to stop the battery functioning and eliminate from the equation, but who knows?

Do we know what their inverter is?

They could have just swapped the ct clamp around and see what happens, they haven't done that yet as far as we know.

Their solar array may be big enough to cover a lot of their use in the sunnier months, but like you, I doubt their battery is big enough to be of huge benefit throughout the year.

It is a FoxESS system, the  manual says the arrow should point towards the grid. I'm sure if they just turn it round it will be fine. If they aren't comfortable doing that they should isolate the battery and solar system as it is costing them money.

matt_drummer

chris_n said:

It is a FoxESS system, the  manual says the arrow should point towards the grid. I'm sure if they just turn it round it will be fine. If they aren't comfortable doing that they should isolate the battery and solar system as it is costing them money.

I may have missed it but I have never seen them say what system they have, I guess you recognise the app?

I agree with you, there was nothing wrong with their old meter and there is nothing wrong with their new meter. The smart meter installer has probably put the clamp back on the wrong way around. A simple call to the installer could confirm it.

I also agree that the battery is going through multiple charge and discharge cycles each day, it could have just been turned off to isolate the problem.

All they need to do is swap the clamp around and see what happens.

chris_n

OP says on page 2 it is foxess.

Petriix

To be absolutely clear: the figures shown on the app are entirely consistent with the CT clamp being reversed. 3kW of solar showing as 3kW of import with the house supposedly using 6kW + whatever the battery is providing. Reverse the clamp and suddenly it's 3kW of export and the battery knows it can charge. Simple.