Tesla Powerwall THD

I know there are several other posts on this topic, but no one has ever really answered the question.

Does anyone have a Tesla Powerwall 2 setup with a Power Plant P15 or P20 that can respond with the input THD and oscilloscope results while running on battery power?


It should be the same as the distortion when running on the solar system you would be using the same inverter either way.

Are you sure it’s using the same inverter? I believe they either contain one in each powerwall unit or an external one for the batteries alone as many systems have micro inverters that only support the panel it’s connected.

Adding solar made no difference in my P10 incoming thd. nor to my apparent SQ.

I can’t justify a power wall though.

Edit: one can choose based on need with or without inverter. AC or DC coupled.

1 Like

I’m no longer concerned about this, as my interest in the Powerwall was as a backup solution, and it is wildly expensive for that use. I’m having a Generac generator installed as a far less costly solution which can cover multi-day outages instead of multi-hour.
BTW, Tesla was unable or unwilling to reply when I inquired about THD.

Generac is not making a storage unit too.

Unless one needs/wants truly off-grid, the ROI on the batteries is a tough sell.

Wait a decade for lower cost and higher capacity.

Absolutely the very best ‘feature’ of having solar is running the AC with the windows open for fresh air!

We like to use all we make as Net 2.0 pays very little back on the excess.

I read an Australian study of the first gen power wall and I believe the life expectancy was ~10 years but the ROI was ~20 years!

Generac’s batteries start at US$10K for 9kWh, IIRC. Considerably more costly than Tesla.

I should probably mention that I’m also having 16kWH of SolarEdge panels installed as part of the installation, thus capturing 26% tax credit this year.

I have seen Generac units listed for $4000 discounted to $3500. I believe they are 7.6kw capacity. I have a 10k solar system I have been using for 7 years so far. It would be nice to have the backup capability.

I’m also putting in a 10kWh generator. Here a mile from downtown Portland, I’ve had three three to four-day outages in the last eight years - third-world electrical infrastructure on poles amid 75 foot trees.

1 Like

I have forty photovoltaic panels (at 325 w each) and four Tesla Powerwall II and I run my house without the grid for about 95% of the time (when hurricanes and storms are announced I use the grid during the storms until power fails). Each panel has a micro inverter attached. I have noticed that with the solar system and batteries, the system produces a better sound than with the grid. Why? I don’t know, but I can hear it. And a friend brought an oscilloscope and the system produces a perfect sine wave. I am not an engineer, but my friend is and he has a solar and Tesla system too and he swears by it. In addition, I have two Audioquest Niagara 7 in my music system and they do make a difference. Why? I don’t know, but even with the perfect sine wave it helps.

1 Like

The battery DC needs to be converted to AC. It’s the same as what UPS and the PowerPlants do. Perfect sine is good. Read up on how the PowerPlants regenerate AC to see why it matters.