Powerwall 2 and Smart Meter accuracy


Thanks @Iwsmiser. I just found that document too. I note that on the front cover is says ‘For large business users’.

I have also just found this document:

https://www.ukpowernetworks.co.uk/internet/en/about-us/documents/2019/southeast/South Eastern Power Networks LC14 Statement 2019 V2.2.pdf
(Sorry, I can’t see how you inserted a pdf, I can only see how to upload pictures as jpegs etc. via the Upload button)

It’s the current UK Power Networks Notice of Charges for my area - South Eastern Power Networks plc. Page 12 - Para 2.49 is the relevant place. It states that when an individual HH (Half Hourly) metered MPAN reactive power at (LV) Designated Properties (whatever they are?) exceeds 33% of it’s total active power, excess charges will apply. The text of this document hasn’t changed for several years.

As far as I can tell, my meter is not measuring reactive power, at least not separately, so I can’t see how they can apply a surcharge. It all looks highly suspicious. However, now that I know that South Eastern Power Networks are my actual suppliers (EDF are just middle men) I’m going to ring them in the new year and hopefully talk to someone who understands about reactive power. They probably installed the meter too, maybe it’s incorrectly programmed. I’ve found nothing so far to suggest that domestic customers are being charged for reactive power. This only appears to apply to industrial customers with meters that separately measure and report reactive power, which has been the case for a number of years.

On a slightly different note, I’ve just determined, via my consumption graph on the EDF website, that when the Powerwall is charging from excess solar, my hourly energy consumption drops to a very low value, e.g. 0.01kWh, as opposed to the normal 0.08kWh as shown in my previous post. I’ve yet to confirm this on my remote display, I need a sunny day, but it would tie in with what Tesla said about the AC-DC converter drawing some power from the grid when on standby.


Tesal Enegy have just come back to me, asking for details of my Smart Meter and energy provider. I get the impression that other people are having the same problem. Sounds encouraging. EDF Energy provider, are currently playing hard to get - no further response to requests for a progress report. i shall keep on at them.


At last I’ve got some signs of action from EDF, mainly because one of their managers with an experimental home battery is finding a similar problem. I’ve posted details on the Tesla Motors Club UK forum here: > https://teslamotorsclub.com/tmc/threads/beware-smets2-meters.188061/#post-4565158

It seems that several people have noticed a similar problem although with differing amounts of spurious energy being metered.