Help with LuxPower system, please - disagreement with smart meter

QrizB

The benefit of having it house side is that you're measuring the same thing that the meter is measuring (there are unmetered parasitic loads in the meter). Good practice, but unlikely to explain your discrepancy.

We really need some Lux people to join this thread. @EVandPV perhaps, @mickyduck55 or @Solarchaser ?

mickyduck55

Im not sure I can be of any real help here I never look at my smart meter.. 

Have you looked at "DATA", "Energy to user" I think that is supposed to be the electricity supplied by in our case Octopus.  The graph on the front page Orange line is what you have used not necessarily from the grid... can be solar+Battery+Grid... I THINK 

I typically export a trickle of electricity on and off during the day but this really nothing 0.2 kWh total unless of course the sun is blazing and batteries are full etc.

My Solar generation measurement is always higher at my generation meter and using the SMA software but again we are talking small amounts.

Typically the battery ramps up so if I put the kettle on I "may" see some import from the grid but its transient and a small amount, the same happens if I switch everything off.. while the batter / Lux closes down I may export a tiny amount

@EVandPV has stated a couple of times that the LUX data is not exactly real-time (I agree) but over a day you would expect the numbers to be close.

If I had to believe a number it would be the Octopus one

QrizB

I recall that in the depths of my Sofar settings there are some that allow you to adjust the zero offset of the CTs. I've never bothered to touch them. Is there anything like that in the Lux?

And a question for you - since having the smart meter fitted have you ever generated enough power to allow export? What does the Octopus data look like for an export day?

Solarchaser

Thanks for the tag QrizB. 
I typed out a big long reply and the page refreshed and deleted it.
Frustrating. 

Anyway Astacus, id suggest you make doubly sure the clamp is pointed the correct way,  which is to the house rather than to the meter.
Also separate the pos and neg tails a bit more at the ct clamp so you are not picking up reverse current from the negative lead.

The lux will be wrong, the smart meter will be right.

If you are sure all of the above is OK, then I'd say email lux and say you are using energy the lux is not seeing, they will apply an offset for you, and then you monitor it and get them to increase or decrease.

I originally had mine at 100w, then realised I was exporting 1kw every couple of days in the dead of winter.
Reduced it to 60w, and thats right for me, may be more or less for you.

As regards the accuracy of the clamps, you may find this thread useful.
I'd hoped by now to update it with monetary savings, but octopus are being a bit over promise and under deliver at the moment unfortunately. 

https://forums.moneysavingexpert.com/discussion/6311640/home-batteries-cause-you-to-buy-more-electricity#latest

Solarchaser

Consumption figures are rubbish for me, though I've always put that down to the fact I'm running parallel inverters,  so it wants to split everything between them... and it doesn't quite work

EVandPV

Agree with what's already been said re CT clamps will never be as accurate as a smart meter or pv meter. 
One other thing to check is what firmware your Lux is on. You can check it on the web portal under configuration > inverters.
Some firmware versions seem to mess up the CT clamp readings causing some export or import when the batteries are discharging.
I'm currently on version BAAA-1111 which seems to be ok.

Astacus

My firmware: (single inverter), is

AAAA-191B

At the moment, this is what I have gleaned:

1. The CT clamp should not be construed as accurate
2. The new Octopus smart meter should be taken as definitive
3. The old (pre-smart) meter could have been under-reporting

Starting from Octopus smart as the ground truth, then I can accept the other outcomes - notable that the clamp is under-reporting - see the graph in my original post, comparing kWh to use with Octopus reading. A strong, linear relationship with a slope greater than one.

What I cannot reconcile is why, under conditions when we're \living off' the battery each morning, or later, when we are generating enough solar to recharge the battery, does the Octopus smart meter report a consistent, slightly variable, draw from the grid of 100 to 200W. At the same time, the 'consumption' trace on the lux monitor is showing a solid zero.

Any thoughts?

Thanks
Rob

Petriix

Astacus said:

My firmware: (single inverter), is

AAAA-191B

At the moment, this is what I have gleaned:

1. The CT clamp should not be construed as accurate
2. The new Octopus smart meter should be taken as definitive
3. The old (pre-smart) meter could have been under-reporting

Starting from Octopus smart as the ground truth, then I can accept the other outcomes - notable that the clamp is under-reporting - see the graph in my original post, comparing kWh to use with Octopus reading. A strong, linear relationship with a slope greater than one.

What I cannot reconcile is why, under conditions when we're \living off' the battery each morning, or later, when we are generating enough solar to recharge the battery, does the Octopus smart meter report a consistent, slightly variable, draw from the grid of 100 to 200W. At the same time, the 'consumption' trace on the lux monitor is showing a solid zero.

Any thoughts?

Thanks
Rob

The constant draw from the grid is simply because the CT wrong so the battery is delivering 200W too little or charging by 200W too much. If it can't see the 200W coming from the grid then it will be working as if that power isn't flowing.

Hopefully they can adjust the settings to compensate. 

EVandPV

Astacus said:

My firmware: (single inverter), is

AAAA-191B

At the moment, this is what I have gleaned:

1. The CT clamp should not be construed as accurate
2. The new Octopus smart meter should be taken as definitive
3. The old (pre-smart) meter could have been under-reporting

Starting from Octopus smart as the ground truth, then I can accept the other outcomes - notable that the clamp is under-reporting - see the graph in my original post, comparing kWh to use with Octopus reading. A strong, linear relationship with a slope greater than one.

What I cannot reconcile is why, under conditions when we're \living off' the battery each morning, or later, when we are generating enough solar to recharge the battery, does the Octopus smart meter report a consistent, slightly variable, draw from the grid of 100 to 200W. At the same time, the 'consumption' trace on the lux monitor is showing a solid zero.

Any thoughts?

Thanks
Rob

Judging by your firmware, I think you have a parallel inverter. Maybe @Solarchaser can confirm ??
Some of us have also had the import/export issue, this is something only Luxpower can fix but an email should be enough to get them to make some remote adjustments and reduce or hopefully even eliminate the problem.

Solarchaser

My firmware is BAAB-0404 so I don't think yours is parallel. 

I think if you take the view that your ct clamps are under reading by around 200w, that should account for everything that you are seeing.