Help analyzing Tesla Powerwall energy issues.

[SolarInAZ]

I have an 8.5Kw system. I have two version 2 powerwalls. When I use them I have less energy credits (my bill goes from -65 a month to -35 a month - I am trying to store as much energy credit as possible for the summer months, here in northern arizona).

After looking at my powerwall app on my phone, I really think there must be some problem. First off, it shows my house as zero kw use, until my power wall exports energy, then it's insanely high. I do not have any AC or other power peaking at noon. It's almost like an expected power use in the neighborhood. It happens again at 3:30 or so.

Is it possible that this install was done wrong? It was a rush job - I sent a nasty gram to Elon Musk 3 days before our contract was to expire because they hadn't done the install. They showed up the next morning, and had everything running 2 days later, in the nick of time.

It just looks wrong when my powerwalls are on.

Her'es the screenshot from my Tesla app.

 

[SolarInAZ]

I think that when it uses the powerwalls, or tries to, something goes awry.

Here are my settings:

 

[power.saver]

Your CTs are not set right. There should be no solar (yellow) production at night. Fortunately, this is usually easy to fix. Have your installer come out and show them this picture.

 

[SolarInAZ]

What is a CT?????

My installer was Solar City Tesla.

Looking at the details, peak hours start at noon, and that's when my tesla batteries start exporting power. Unfortunately as you can see, it suddenly believes my home power usage has skyrocketed. Nothing has changed, and the AC is not on. That's insanely high usage too.

Here's the details

 

[MorrisonHiker]

It's obvious from those images that the CTs are reporting things incorrectly. If you call, they can fix that over the phone. It took them a couple hours to get mine set correctly but they have worked correctly ever since. Give them a call and they might be able to fix it remotely.

Here's an example of how a properly configured system looks. You will see blue usage throughout the day. If solar and the Powerwalls cover the usage then the blue is not as noticeable but you can still see consistent usage all day and how the yellow solar only shows during daylight hours.

 

[power.saver]

CT are Current Transformers, they are a device that the load and solar wires run through to detect current flow on the circuit. They are most likely installed on the wrong wire, or backwards. It's easy to make this mistake (happened to me) and can be corrected by relocating them to the right wire. They are also configured in the wizard, so it can often be fixed by the installer by just going in an adjusting the settings. In any case, they didn't do it right, so the app show ridiculous data and the PWs aren't operating properly as a result.

 

[SolarInAZ]

Well there you go. I called Tesla and this time I could actually explain more of the problem. I gave up a couple months ago, as I've related in other threads, and just turned them off.

Now with more info, including my app showing solar production at night, they will have somebody contact me 24-48 hours to fix it.

I thought they must be really efficient solar cells, getting power from the stars at night. lol.

I really hope they can fix this.

 

[MorrisonHiker]

Do you only have peak and part peak rates? It doesn't look like you've set it up for off peak rates so it doesn't know when rates are the cheapest.

Also, just because you are seeing bad data, it doesn't mean your Powerwalls are using energy as shown. They might not be performing optimally but they shouldn't be causing your bills to go up in the middle of the day when you are sending power back to the grid.

 

[MorrisonHiker]

Well there you go. I called Tesla and this time I could actually explain more of the problem. I gave up a couple months ago, as I've related in other threads, and just turned them off.

Now with more info, including my app showing solar production at night, they will have somebody contact me 24-48 hours to fix it.

I thought they must be really efficient solar cells, getting power from the stars at night. lol.

I really hope they can fix this.

Great. When I called, they first changed a few settings remotely. Some data looked better but others got worse. They watched it for a day and changed a few more settings remotely and fixed it.

 

[power.saver]

Keep us posted... once they are working right I think you will like them!

And as @MorrisonHiker said, if you don't have a part-peak, configure all the non-peak time as off-peak to ensure the best operation.

 

[MorrisonHiker]

Here's an example of a day with off peak, part peak and peak settings.

I purposely adjust the hours so that the Powerwalls power the house longer.

 

[TomHudson]

Eagerly watching this thread now! I hope you can get this straightened out... so nice to see user-to-user help.

We're thinking of adding PowerWalls but have an existing small PV installation I installed in 1999 and I'm not sure if they'd want to connect to it.

 

[miimura]

Eagerly watching this thread now! I hope you can get this straightened out... so nice to see user-to-user help.

We're thinking of adding PowerWalls but have an existing small PV installation I installed in 1999 and I'm not sure if they'd want to connect to it.

As long as your solar is grid-tied, there's no reason for Tesla to have any reservations about installing Powerwalls with it.

 

[PBBear]

Now with more info, including my app showing solar production at night, they will have somebody contact me 24-48 hours to fix it.

Your sensor clamps are clearly seriously screwed, confusing the battery management algorithms - while they might be able to sort it out remotely, its likely the clamps have been installed on the wrong wires in the back of your meter-box and someone will have to visit your house to fix them.
48 hours later - how have you got on with getting this resolved?

 

[SolarInAZ]

Your sensor clamps are clearly seriously screwed, confusing the battery management algorithms - while they might be able to sort it out remotely, its likely the clamps have been installed on the wrong wires in the back of your meter-box and someone will have to visit your house to fix them.
48 hours later - how have you got on with getting this resolved?

I haven't. They did not call back as promised two times now. Nobody has shown up to correct the issue.

I am going to call again this morning.

 

[trmmcd]

I had a related issue. When they completed my install - the sun was down so they couldn’t really test it. Needless to say it didn’t work when the sun was out and they had to come back. It turned out that 2 CTs were reversed. After they fixed the first one, things improved, but the power consumption from my home was not being reported correctly. After they fixed the second one - everything worked just as expected. Now it is working great. I should say that I was adding the PW to an existing solar system from another provider so I imagine the install was a bit different than they are familiar with. It also showed how critical it is for the sun to be out and solar active to know whether it is set up correctly. A mis configuration causes all kinds of nutty results.

 

[Shygar]

Tesla Powerwall support actually noticed my CT's were setup incorrectly without me even reporting the issue. They just called me one day saying they were coming out tomorrow to fix it. Definitely a CT issue.

 

[SolarInAZ]

Nobody has come. Nothing has changed. I've opened tickets. I have called support and been told that they would have a service team call. nobody calls.

I'm giving up again. I turned them off yesterday. They are worthless, just taking up space in my garage.

 

[miimura]

@SolarInAZ any progress with Tesla fixing your problems?