Odd, Persistant Grid Draws in Self Powered Mode.

[dandrewk]

Greetings, first time poster here... and a new owner of three Powerwalls. I posted this issue in the FB group but got no answers, and I'm waiting (and waiting... and waiting...) for Tesla tech support to "reach out to me"... Hoping someone here knows the answer.

My purpose is to be self powered and have backup. It's only been a few days, but I've noticed that I get persistent grid draws throughout the day. They typically last a few seconds to a minute or two and are .1 to .3 KW. Small draw, but it's been around 2 KWH per day.

If this is for smoothing current spikes, why isn't it going both ways? I'm at about 93% self powered, it should really be 100% It's not a major deal, and I'm loving the setup so far. Just wondering if this was normal.

 

[bkp_duke]

I have three PW2s and I have always seen something similar since they were installed 14 months ago.

A few differences between yours and ours:
1) We do see some smoothing on export to the grid
2) Ours appear less frequent than yours

On software version 1.37.1.

 

[dandrewk]

I have three PW2s and I have always seen something similar since they were installed 14 months ago.

A few differences between yours and ours:
1) We do see some smoothing on export to the grid
2) Ours appear less frequent than yours

On software version 1.37.1.

Thanks. Did you see that "smoothing" or less grid draw frequency improve over time, or has it always been the same?

 

[bkp_duke]

It has been the same, but less than what you showed in your images.

When we have had power outages, however, the powerwalls have worked flawlessly.

 

[NuShrike]

Do the mystery grid-spikes correlate with largish swings in home usage?

From your graphs, there seems to be some correlation. If you have some other system to plot the grid/battery vs home usage at a higher frequency, you may be able to see deeper into what's happening.

I have Neurio and Sense in my setup and I can see the PW has a slight lag (one second more/less) catching up with home power-draw (or solar swings) -- biased toward pulling from the grid than oversupplying from the battery. The bias would make sense for the USA where the battery is not to export.

From my Neurio/Sense CT plots, I can see the PW supply is about 30W +/- behind grid usage. Meanwhile, PW charging is always a little behind solar supply (this makes sense).

 

[miimura]

Do the mystery grid-spikes correlate with largish swings in home usage?

From your graphs, there seems to be some correlation. If you have some other system to plot the grid/battery vs home usage at a higher frequency, you may be able to see deeper into what's happening.

I have Neurio and Sense in my setup and I can see the PW has a slight lag (one second more/less) catching up with home power-draw -- biased toward pulling from the grid than oversupplying from the battery. The bias would make sense for the USA where the battery is not to export.

From my Neurio/Sense CT plots, I can see the PW supply is about 30W +/- behind grid usage. Meanwhile, PW charging is always a little behind solar supply (this makes sense).

Everything you said above is right on the mark. However, the magnitude and duration of his grid usage spikes visible in his chart are much larger than normal. He was right to contact Tesla about it because it is abnormal.

 

[dandrewk]

Thanks for the info. I finally got ahold of Powerwall tech support. (PSA: Call around 7 PM PDT. If you still get forwarded to Solar panel support, ask if they would kindly transfer to PW support.) The agent saw the issue and said they will collect data for a couple of days and escalate to a higher tier, and asked that I don't power cycle of do anything until the call back.

I'm hopeful.

 

[NuShrike]

OTOH, I'm getting problems with PW lagging in or not catching up at all in TBC-balanced-shoulder during sunset and peak TOU.

I think I'll jump back to self-powered where my experience is consistent, and flatter than yours: