Octopus Solar and battery usage discrepancy with Givenergy app

HandsHairy

My query concerns a discrepancy in usage between Octopus energy and the Giv Energy app.

A couple of months ago I had a GivEnergy 9.5kw battery, 5kw inverter (gen3) and 10 solar panels fitted. For the first month everything appeared to be working fine.  My meter readings indicated a usage from the grid of around 11kwh for the month, which is in line with my expectations for this time of year.

I then had a smart meter installed by Octopus and now I’m being billed for around 3kwh and 5kwh per day.

The charts below show that we appear to be drawing around the same amount of energy from the grid through the night until around 9am and then we draw again from around 6pm. Meanwhile, our battery never drops below 20%.

This apparent usage broadly mirrors the timing and amount of energy we draw from the battery and consume in the home. 

I have not touched the inverter settings, it’s set at 96% usage, no timed charge, discharge or export. We are on Octopus Flux tariff.

This is puzzling me. I’m thinking that there’s an issue with the smart meter installation, but it would be very useful to have your input on what is going on!

debitcardmayhem

What does the battery charge say e.g.

Qyburn

The smart meter readings will be correct. I suspect a problem either with the accuracy of the Givenergy metering, or maybe the CT clamp wasn't properly reinstalled when the smart meter was fitted. The black thing on the live cable between meter and Henley block.

BarelySentientAI

Qyburn said:

The smart meter readings will be correct. I suspect a problem either with the accuracy of the Givenergy metering, or maybe the CT clamp wasn't properly reinstalled when the smart meter was fitted. The black thing on the live cable between meter and Henley block.

At least the CT looks to be measuring import (which makes sense to me).

The last one we had on here was pointing the wrong way.

debitcardmayhem

Qyburn said:

The smart meter readings will be correct. I suspect a problem either with the accuracy of the Givenergy metering, or maybe the CT clamp wasn't properly reinstalled when the smart meter was fitted. The black thing on the live cable between meter and Henley block.

The givenergy metering should be fine, but the data shown does not tell the whole story.
The two grid screens should tell the whole story, along with the two battery screens.

HandsHairy

Do these charts help?

Qyburn

If you really think that Givenergy is correct then the smart meter clearly isn't. You could try switching everything off and see if the smart meter increments.

But my guess is still that the smart meter is more likely to be correct. Did you check the CT clamp? 

Reed_Richards

I'm struggling to understand what the problem is, could you please be more explicit.  Is 11 kWh per month what you hoped to be using after you got the panels and the battery?  Could it be that the meter you had before the smart meter was fitted was under-reading.  That is perfectly possible if you had the old type of rotary dial meter that went backwards when you were exporting solar power.  Or it could just have been otherwise faulty and under-reading.     

HandsHairy

Reed_Richards Qyburn thanks for responding.

I think the issue I’m struggling with is best shown in the Octopus chart above, showing we imported 5.5kwh on 30th July, with the usage spread throughout the night, and then from 6pm. Each day follows the same pattern. However, we have a 9.5kw battery and 10 panels with more than enough capacity to cover our usage. Below I’ll post a pic of the battery usage for the same day and it’ll show that we had huge amounts of battery stored, but Octopus shows us drawing a modest amount from the grid. This wasn’t the case before the smart meter was installed. 

Qyburn: I know what the CT Clamp looks like, but no idea what I’d need to check! 

Thanks again, appreciate your input….

tim_p

If the CT clamp was moved during meter install then it should be a simple task to flip it the other way and you should see the effect fairly quickly. A properly set up battery system shouldn’t be importing anything like 3-4kWh overnight. My system is only importing around 250Wh each day, max seems to be 9kWh total per summer month (actually since and including April)

HandsHairy

thanks Tim. Your usage is exactly in line with my expectations and the usage prior to having the smart meter installed.  Something is clearly wrong with the meter install, but I’ve not got the knowledge, and Octopus can’t get anyone to me for weeks!