New 26kw system - some weird usage results after a month of use.

[aimetti]

Hello all,

A few months ago I had my 26kw 3 pw system put in. Overall its been great. I have always had a ton of usage at my house , regularly hitting 2000/2500 kwh a month.
The first month the system was running amazing. Fully off grid , batteries charging up by 11/12 in the morning each day with ease. In the app I noticed no irregularities as far as usage goes etc. My first month of usage was in line with my normal amount around 2700 kwh as it was very hot and AC / pool was running quite a bit.

Fast forward a month and ive begun to notice a few oddities when it comes to usage. The last month my usage was at 3900 kwh. A new all time record for my house. I also noticed my batteries were not charging to full even on high sun days. I figured must be due to my own doing and taxing the electricity. Just in case I did some digging and looking at the usage in the app. I started turning off some breakers to see why I was using so much electricity. The house was randomly pulling 12 kW and all I had running was the necessities. I got to the point where I turned off the entire house. Somehow with my house was still consuming 5.5 kw with only my solar active charging my batteries. It was around 1pm and my batteries were still only around 60% charged. I was pulling in around 24 kW from the solar 5.5 of which were going to house and the other 19 or so going to batteries.

I cant remember ever seeing this high of usage while the solar was generating. With the whole house turned off , does the solar generation actually use some of the power? The random house usage seems to go higher the more solar I generate. I turned off my main inverter and my solar production dropped to 9 kW but my house no longer consumed any power. I turned off the other 2 inverters and put the main one back on, solar jumped up to around 17 kW and sure enough my house usage also went up to 3/4 kW. So either it seems the one inverter is pulling a ton of power or its due to the system pulling in alot of electricity?

Sorry for the long post , curious if anyone else has seen similar results.

 

[aesculus]

Sounds like a CT is either broken or in the wrong place. Not sure why it worked for a month though. Perhaps the component that the CTs are installed in went south?

BTW I had a circuit that had both a load and solar on. Tesla was able to deal with this by putting in CTs on the same circuit but for different measuring points. Still trying to figure out how it works, but it does. Before that I would get readings that were crazy like yours when solar did not offset the load etc.

 

[aimetti]

Cool thanks for the reply. I coulda sworn it was working before but then again I was new to the whole system and wasnt really looking into it as in depth as I am now. I can definitely see a difference in amount of usage now though and I think i would have noticed it before.

 

[aimetti]

So my system finally got approved for power on. I have let it run for a few weeks and still seem to be having the same problems it turns out. I can actively watch the solar generation go up to lets say 24 KW and my home usage bumps up to 7/8 kw (when not actively using anything) As the sun goes behind a cloud the generation will drop to say 11kw and the home usage down to 2/3 kw. Tried the main breaker again and sure enough house still draws as solar is being generated. I contacted tesla and they think something is definitely up. They updated the inverter firmware and will have a tech reach out in a week or 2. Ill keep up this up to date w/ info and hopefully resolution just in case anyone ever has similar issues.

 

[getakey]

can you post some screenshots from the app?
I'm betting CT installed wrong too

 

[aimetti]

Hey! Which screenshots you looking for ? The main screen showing the home / powerwall / grid?

 

[aimetti]

Did a little digging and it looks like I have a neurio remote ct. not sure if that helps or not either. I was watching the Tesla install videos about the net metering and realized I had the antenna sticking out of the breaker box.

 

[getakey]

Hey! Which screenshots you looking for ? The main screen showing the home / powerwall / grid?

Preferably the solar generation graph when you go to the Energy page

 

[aimetti]

Here you go. Thanks !

 

[aimetti]

I noted down the usage at the meter 10 days ago and added up the total grid used in the app since then and it did add up. Was within 5 kWh. So pretty close. So it’s not just a metering question at this point I don’t believe but real usage.

Does the system actually use electricity to run or something. The more solar generating the higher the usage (even with breaker off to house).

 

[getakey]

did you have intermittent clouds that day? Should only have spikes and valleys with clouds. Otherwise CT is wrong
here is mine with CT wrong - not exactly like yours but similar

 

[aimetti]

Ya there was definitely some clouds today. The peaks and valleys are most likely that.

As the peaks / valleys also show for solar generation you can also see the home usage drops / goes up at the same rate.

I just don’t get how if I have the main breaker off for my house completely and my roof is generating 25kw. How are my powerwalls only getting 17ish kw of that and 8kw is going to “home” usage. If I turn off inverter 1 I can instantly see the generation go to like 12kw and only 1/2kw going to home. (Still with entire home breaker off).

With the usage adding up on my meter matching the app it seems like the system is legitimately sending power to my home with nothing being used. Unless I’m completely not understanding this which is very possible

 

[Jedi2155]

If you're completely off-grid, and the powerwalls are getting 17 kW and the remaining 8 kW going to "home usage" then there is definitely a miswiring of the CT's somewhere.

17 kW sounds about right in terms of 3 powerwalls fully charging (5.8 kW * 3).

My suspect is that due something miswired, its calculated "home usage" as Solar Generation minus Powerwall load = Home Usage. Either solar generation is wrong, or home load is wrong.

 

[aimetti]

If you're completely off-grid, and the powerwalls are getting 17 kW and the remaining 8 kW going to "home usage" then there is definitely a miswiring of the CT's somewhere.

17 kW sounds about right in terms of 3 powerwalls fully charging (5.8 kW * 3).

My suspect is that due something miswired, its calculated "home usage" as Solar Generation minus Powerwall load = Home Usage. Either solar generation is wrong, or home load is wrong.

Thanks for the reply. Ya the entire house breaker is off so its really just the solar and it charging the batteries. so instead of the roughly 24/25kw at max going to the powerwalls only a portion is and the rest is going to whatever that home usage is.

I did notice my last 2 months of use were off the charts compared to normal. its as if that electricity is actually being used somewhere.

 

[aimetti]

Little update today while I wait for Tesla to get back in touch with me

Right now I’m producing 14.9 kw and my home is “consuming” 7.1 kw.

I turned off the breaker for the nurino ct and the app instantly went to 7.9 kw of solar producing and the home using 0kw.

That must mean there’s another ct on one of the 3 solar runs / inverters that’s able to still monitor electricity usage? And also means the nurino is monitoring some solar and also the house usage?

Was watching clouds as they blocked the solar generation and as soon as the solar dips so does the home usage.

Really curious what they come back with.

 

[Tiger]

Little update today while I wait for Tesla to get back in touch with me

Right now I’m producing 14.9 kw and my home is “consuming” 7.1 kw.

I turned off the breaker for the nurino ct and the app instantly went to 7.9 kw of solar producing and the home using 0kw.

That must mean there’s another ct on one of the 3 solar runs / inverters that’s able to still monitor electricity usage? And also means the nurino is monitoring some solar and also the house usage?

Was watching clouds as they blocked the solar generation and as soon as the solar dips so does the home usage.

Really curious what they come back with.

Is your system pushing power back to the grid? Sure sounds like it is showing (either all or part of it) power sent to the grid as power consumed by the house.

But again, strange that somehing like this would change after installation, unless it is configured in software.

 

[aimetti]

Is your system pushing power back to the grid? Sure sounds like it is showing (either all or part of it) power sent to the grid as power consumed by the house.

But again, strange that somehing like this would change after installation, unless it is configured in software.

Ya I compared the meter for electricity used and sent out in the time period and its actually within a few KW on each of them w/ the app.
So its actually real usage coming from my system. Maybe I just dont understand how the system works and the more it generates the more the house uses?

As I pointed out in the previous post , I can literally turn off my main breaker for the house so not a single thing is on. As the solar generation goes up the app shows the home usage goes up. And its actually real used power as its not charging battery at the full amount if its under 100% , and if the battery is 100% only a fraction is going to the grid , rest to the house.

The system is literally the only thing on in my home at that point.


Maybe the question I should be asking everyone is do they see their home usage go up / down with the amount of solar generation take place. Maybe its the same for everyone?

 

[jboy210]

Ya I compared the meter for electricity used and sent out in the time period and its actually within a few KW on each of them w/ the app.
So its actually real usage coming from my system. Maybe I just dont understand how the system works and the more it generates the more the house uses?

As I pointed out in the previous post , I can literally turn off my main breaker for the house so not a single thing is on. As the solar generation goes up the app shows the home usage goes up. And its actually real used power as its not charging battery at the full amount if its under 100% , and if the battery is 100% only a fraction is going to the grid , rest to the house.

The system is literally the only thing on in my home at that point.


Maybe the question I should be asking everyone is do they see their home usage go up / down with the amount of solar generation take place. Maybe its the same for everyone?

Our usage goes up based on what we use, regardless of generation.

What are your settings under Settings | Powerwall? We are Self-Powered, Energy Export-Solar, Grid Charging-No. I believe Time-Based controls will attempt to figure out what is the cheapest way to operate based on your Utility Rate Plan.

 

[GRV0928]

take a video while it doing it…

 

[aimetti]

Our usage goes up based on what we use, regardless of generation.

What are your settings under Settings | Powerwall? We are Self-Powered, Energy Export-Solar, Grid Charging-No. I believe Time-Based controls will attempt to figure out what is the cheapest way to operate based on your Utility Rate Plan.

Here’s a ss
Yea figured that’s how it works. Odd then how house is completely off and usage is 100% dependent on how much generation I’m doing.

I’ll take a video tomorrow if I’m around.