Smart meter incorrect installation caused increased energy usage

Kateg28

I don’t understand the question. I have looked at my old bills and we were using around 18kw a day (total divided by 90 as a simple Calc). I thought it was 13kw but I was looking at the total bill and dividing by cost per kW but there was government subsidy so it wasn’t a clever way of calculating. 

I agree the app is an estimate but the smart meter is reading at 25+ kw per day and that is what is worrying me.  

We have actually turned off the array at the moment and looking at house consumption and it has plummeted. 

All that is running is the fridges and freezers, the tv and one laptop is charging. 

We do not have storage heaters or immersion tanks or any of the usual suspects. 

Kateg28

I have 8 x 390w panels and 5.2kWh battery. 

Qyburn

Kateg28 said:

We have actually turned off the array at the moment and looking at house consumption and it has plummeted. 

Actual consumption, as measured by the Smart Meter? Or are you comparing smart meter reading now, compared to what the app said earlier?

I am as sure as I can be (given lack of hard information about your system) thst your solar app does not actually measure the house consumption at all. I think it measures solar output and grid import/export, and assumes the difference is being used by the house. And since one or both of those is screwed, it comes up with stupid figures for the house.

CSI_Yorkshire

Qyburn said:

Kateg28 said:

We have actually turned off the array at the moment and looking at house consumption and it has plummeted. 

Actual consumption, as measured by the Smart Meter? Or are you comparing smart meter reading now, compared to what the app said earlier?

I am as sure as I can be (given lack of hard information about your system) thst your solar app does not actually measure the house consumption at all. I think it measures solar output and grid import/export, and assumes the difference is being used by the house. And since one or both of those is screwed, it comes up with stupid figures for the house.

I agree - there are possibly two problems here and they are getting confused together.

First problem - what is your app saying and why does it think your house is sending power to the grid and to your batteries, because this is impossible.  I think Qyburn's probably right there, it's the app measuring something wrong.

Second problem - you think your actual consumption on your actual meter has gone up a lot.  Are your meter readings wrong (pretty unlikely I think), or are you actually using the energy and we need to track down where.  That could be because the old meter was hiding it, because something has been turned on that you can't find, or because something is going wrong with how the solar/battery system is working.

You probably need to pick only one of these and focus on that first otherwise it will keep going round in circles.

Gerry1

Dolor said

If your actual power is 55kW then you have a problem: that is over 200amps. What are you running?

Kateg28 said:

I don’t understand the question. I have looked at my old bills and we were using around 18kw a day (total divided by 90 as a simple Calc). I thought it was 13kw but I was looking at the total bill and dividing by cost per kW but there was government subsidy so it wasn’t a clever way of calculating. 

I agree the app is an estimate but the smart meter is reading at 25+ kw per day and that is what is worrying me.

This lack of understanding probably arises because the OP still keeps saying kW when she means kWh.

Based on the observed flash rate, it's quite likely that (rightly or wrongly) the meter recorded Energy usage of 55kWh in a day.

However, Dolor correctly pointed out that Power usage of 55kW simply wasn't possible because it would have blown the company's sealed fuse.

Even with a beefy 100 Amp fuse, the maximum power that can be drawn is only 24kW.

To explain once again: Power is an instantaneous quantity measured in kW.  Energy is a cumulative quantity and is measured in kWh.  Muddle them up and the resultant confusion means it can all end in tears.

[Deleted User]

Qyburn said:

Kateg28 said:

We have actually turned off the array at the moment and looking at house consumption and it has plummeted. 

Actual consumption, as measured by the Smart Meter? Or are you comparing smart meter reading now, compared to what the app said earlier?

I am as sure as I can be (given lack of hard information about your system) thst your solar app does not actually measure the house consumption at all. I think it measures solar output and grid import/export, and assumes the difference is being used by the house. And since one or both of those is screwed, it comes up with stupid figures for the house.

Thanks. That’s why I was suggesting that the OP needs to get back to basics. An array of 8 by 390W or 3.12kWp is not a very big array. Even with a battery, the OP will struggle to use more than 75% of the energy that the array generates.

One possible scenario is that export was causing the old analogue meter to turn backwards. This is not possible with a smart meter. (Sorry if this has been mentioned before)

Some solar apps do measure home consumption but it depends on the number and placement of CTs. Third-party apps such as BRIGHT do it a lot better as the information comes directly from the smart meter. ( Before anyone shouts that my home usage is high it includes some hot water heating which is treated as a home load.)

chris_n

Turned the consumer unit off, every circuit was off but solar still running
flashes per minute 29
How? The house is turned off at the consumer unit. Nothing is on at all. 
Yes it is, your battery is on and is charging from the grid! The battery has it's own consumer unit.

CU off, Solar off - continuous red light

QrizB

Kateg28 said:

QrizB said:

Sorry to ask yet another question but do you have a photo of your meter cabinet from before you had solar PV installed?

And one from after solar but before the smart meter?

Unfortunately not. I am kicking myself now. 

That's a shame.

Do you remember whether the old meter was a mechanical one like this:

Or a slightly more modern digital one like this?

Kateg28 said:

Meter reading 188. 

We then did various and counted the red flashes on the meter per minute. 
in normal state this was around 20.

20 flashes per minute = 1200 flashes per hour = 1.2kW import or export, we can't tell (although the display on the meter might indicate which).

Turned the consumer unit off, every circuit was off but solar still running

flashes per minute 29
How? The house is turned off at the consumer unit. Nothing is on at all.

29 flashes per minute = 1740 flashes per hour = 1.74kW export (as solar in on but house is off)

CU off, Solar off - continuous red light

CU back on, Solar off - 14 red flashes

Continuous red light = no import or export, which is the correct state.

14 flashes per minute = 840 flashes per hour = 0.84kW import (as solar is off but house is on).

That's all broadly consistent. If your solar was generating about 2kW and the house was using about 800 watts, you'd expect to be exporting about 1.2kW with everything turned on. (Yes I know the export flashes suggested 1.74kW, not 2kW, but there might've been a cloud or a shadow or something.)

Now, if your house really was using 800 watts with the solar turned off, that seems quite high. I would expect a "typical" house to only use 100-200 watts unless you were running a high-drain appliance. You could do with finding out which of your domestic circuits was responsible. One way to do this is to repeat your test with everything (house and solar) off, then turn off all the house MCBs and re-energise them one at a time, making a note of how many flashes per second each of them adds to the count.

Petriix

I strongly suspect that your grid CT clamp has been fitted the wrong way round. As a consequence, when you're exporting the battery 'thinks' you're importing so pushes out more and when you're importing it sees this as export and tries to store it.

A simple sanity check would be to reverse the CT clamp and see if it fixes it. I'm fairly certain it will. It's not tricky, just unclip it and put it back on the same wire with the arrow pointing the other way. 

Gerry1

As an aside, take great care if you're reading a meter similar to that shown by @QrizB.

Many people would submit 498021, but it's actually 388020 !  The bill would be about £36k too high.

In theory The Mysterious Third Party should spot the mistake, but if it's five years since a meter reader called...