Solar + Pw2 = Offgrid Issues

[Halodynamics]

Hello, new to the forum. Recently had 20kw PV system installed on roof. enphase micro inverters. 3 PW2's grid tied in FL. I have called Tesla 3 times, each time elevated to T2. Finally getting the installer to come back out.

Issue 1. Tesla app shows house demand in what I would call normal range of about 2-4kw all night. As soon as sun comes up and PV system starts producing power, the house demand increases exponentially. some times upwards of 25+kw. it follows the PV production curve until around 8p where it stops producing. then back to "normal" If i have the app set to self powered, when the batteries kick in to supply the 2kw need then again the house demands excessive KWs. Resulting in a battery drain in less than an hour. Nothing has changed except the initialization of the PW or PV system.

Killed the PV system for a day to test the normal power requirements of the house. during peak times no more than a quick spike to 10kw. PW remained off as the grid supplied power 1 for 1.

Issue 2. today i did a off grid test. killed the grid at noon. Beautiful sunny day, enphase says panels are putting out like a champ before the test. Grid goes down, UPS's start beeping computers down. house loadsheds all my heavy hitters (dryer, stove, and 2, 4 tons and 2, 2 tons) rest of house powered and now app shows the PW's running the house, but no solar. PW's were @100% . ( i read some of the other threads about the frequency issues and we are 1.37. PW drops down to around 95% and solar kicks in for a minute and PWs now back at 97% PV goes off. continues like this for 4 hours. House demand is around .7kw I downloaded the heavy hitters at the breaker to see if I could recover any of them at least to see the draw on the system and to see if the PV would pick up the extra loads 1 by 1 and nothing. Reinstated the grid and back to issue 1. It shouldnt offload the Heavy hitters as the essential loads panel is not there. Installers said i didnt need it due to the 3 PWs

Issue 3. 20kw PV system and peak production is 15kw. house demand always seems to pull grid power. House drops to 10kw, PV drops to 8 kw and grid adds 2kw. Nothing goes to recharge battery or gets pushed back to grid. House demands 18, PV gives 15 and grid gives 3kw. The kicker is that when I look at my Meter, it is running backwards and Im pushing power to the grid.

Anyway, just hoping someone can shed a little light on their experience of something similar. last tesla person said it is getting bad data. It is elevated to T2 but it is going on 3 weeks now and Im just looking for a bit of hope.

 

[woferry]

For issue #1 (and #3) it sounds to me like some of the circuits your Gateway's CTs (Current Transducers) are monitoring are backwards. I had similar issues (described in this post) with my system (13.32kW PV w/1 PW2), which uses two Delta Solivia 5.2 inverters, one on the grid-side of the Gateway and one on the house-side. How comfortable/familiar are you with your household wiring? I.e. can you identify circuits and do you know where the CTs are installed? I wound up fixing my issues myself, but I'm an EE and very comfortable with my house wiring (and the circuits Tesla added). I don't know how the micro-inverters get wired-in, I assume with 20kw PV it connects using multiple breakers?

Not sure I'm totally following your issue 2, I believe it is expected (though with the v1.37 FW and a call to Tesla you might be able to reduce the frequency shift such that the UPSs are happy), your PV system is large so the PWs will recharge quickly unless your house load is very high, and the PWs will shut the solar down once the battery gets close to fully-charged. Though if the CT readings are wrong it might mess-up things in this regard as well.

If you do understand the wiring a quick diagram showing the grid/house/PV/PW circuits, and which ones go through the CTs in which direction would help I think. Otherwise best to leave to Tesla's electricians, too bad it's taking so long, though. Some simple issues they can fix remotely, but yours sounds more complicated than that, mine definitely needed physical moving of wires so it wasn't going to be a configuration change to fix it.

 

[Jigglypuff]

Yes, the neurio sensors on our setup were done wrong. A little bit of work by a knowledgeable tesla employee and everything worked right.

 

[boaterva]

They also can usually update the settings in software and don’t need to physically move the CT’s.

I keep seeing these threads and fail to understand why the techs didn’t verify operation before they left. Easy to see generation flow, grid direction, house load and direction. WTF is the usual answer.

 

[Halodynamics]

Thanks for the replies. I guess for issue #2 is it normal for the system to offload high demand items such as AC units? In this case with 2 200amp panels it dropped 1 whole panel. I'm not sure if it has something to do with the items themselves or the system. According to the installers at install I don't have an separate essential be panel. As for the CT issue I'm going to wait for the tech to come out, I'm comfortable with the electrical but swapping things around sometimes gets me in trouble.

Thanks again for the replies

 

[boaterva]

Thanks for the replies. I guess for issue #2 is it normal for the system to offload high demand items such as AC units? In this case with 2 200amp panels it dropped 1 whole panel. I'm not sure if it has something to do with the items themselves or the system. According to the installers at install I don't have an separate essential be panel. As for the CT issue I'm going to wait for the tech to come out, I'm comfortable with the electrical but swapping things around sometimes gets me in trouble.

Thanks again for the replies

As far as I know there is one connections for loads. It can’t adjust dynamically.

I have everything on the PW gateway except the HPWC 100 A circuit. So they installed a new panel between the original and the gateway and moved the HPWC to it. It also has the new main cutoff breaker.

Wonder if they moved circuits around and used one of your 200’s for backed up circuits and the other for not? Sure sounds like there isn’t PW capacity for large loads (AC, dryer, etc). But all of that should have been discussed before installation.

 

[Halodynamics]

So my PV system is rated for 20kw but does anyone know why my Generation at FULL Production would be capped to only 15kw? I have 3 PW2's. On top of the bad info Im getting could that be part of the reason the production is capped? The Batteries telling them not to produce anymore? Even with the Batteries at 50% when the sun comes up I can go pretty quickly to 15kw but then the grid kicks. PV's then kick over to charge the batteries and the grid feeds the house for the overage.

Thanks

 

[MorrisonHiker]

So my PV system is rated for 20kw but does anyone know why my Generation at FULL Production would be capped to only 15kw? I have 3 PW2's. On top of the bad info Im getting could that be part of the reason the production is capped? The Batteries telling them not to produce anymore? Even with the Batteries at 50% when the sun comes up I can go pretty quickly to 15kw but then the grid kicks. PV's then kick over to charge the batteries and the grid feeds the house for the overage.

Thanks

My 16.575 kW system with 3 Powerwalls can produce over 18 kW so I don't believe the Powerwalls are the limitation.

How are your panels oriented?

 

[PBBear]

So my PV system is rated for 20kw but does anyone know why my Generation at FULL Production would be capped to only 15kw? I have 3 PW2's. On top of the bad info Im getting could that be part of the reason the production is capped? The Batteries telling them not to produce anymore? Even with the Batteries at 50% when the sun comes up I can go pretty quickly to 15kw but then the grid kicks. PV's then kick over to charge the batteries and the grid feeds the house for the overage.

Thanks

Suggest you your CT sensors sorted out first ASAP - then see if this is still a thing. It is possible that your CT sensors are including negative house load or some funky combination, so that what is measured as '15kW solar' is really '20kW solar plus -5kW house load'.