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Found out Powerwall only install done by Tesla 4 years ago never received PTO from SCE [tesla produces pdf of prior authorization document]

jjrandorin

Moderator, Model 3, Tesla Energy Forums
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Nov 28, 2018
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Riverside Co. CA
Lol. I know the feeling. Had to restrain myself quite a bit in the top post here :)


Yeah. I'm pissed we didn't know, but I can't blame Semper Solaris or Tesla. Blame goes to responsible regulatory bodies (who are obviously in bed with the utilities). No way there should be this kind of blanket restriction. I can understand them not wanting someone with 30kWh to get both NEM and charge with off peak power, but it does nothing but hurt people in our situation who really can't benefit from anything but the solar itself (NEM will mean nothing for us until early summer).

Got it. My apologies for just skimming the replies out of context (and in reverse) :).

The bottom quote you have ascribed to me, is actually from @charlesj. No worries though, I understand that you are responding to multiple people. I just am pointing it out.
 
Who even sold you this? PW's should have about 6kw per PW!!!
Powerwalls were sold and installed by Tesla and they work fine. It's the new solar that's only 4kwH and thus can't charge our Powerwalls enough to use for TOU shifting as we did when we were able to buy the power from SCE off peak.

And I agree, seems no one needs PTO for batteries since they cannot feed the grid.
Well, in theory the whole system (the Gateway, etc) is grid connected so I understand requiring PTO.
 
Powerwalls were sold and installed by Tesla and they work fine. It's the new solar that's only 4kwH and thus can't charge our Powerwalls enough to use for TOU shifting as we did when we were able to buy the power from SCE off peak.


Well, in theory the whole system (the Gateway, etc) is grid connected so I understand requiring PTO.
If you want your system optimized for charging ESS on the grid, setup the PV so it is not part of the backup system.

If you want your system optimized for off-grid backup duration, then make sure to keep the PV on the backup side of the system.
 
Batteries CAN feed the grid, as shown in the new VPP pilot program. There is a good reason you need PTO for them.
Not to mention . . . your power company will (as in our case) almost certainly refuse to approve the next grid connected improvement if they didn't even know about the first one.

Update:
Continued SILENCE from TESLA. No response to our calls or emails about this for almost two weeks; and of course . . . multi-hour hold times trying to call anyone (support, advisers, etc). Thanks to Tesla actively ignoring me (I am not a quiet person), Edison said we should ask Semper Solaris to add the Powerwall to their approval application even though they had nothing to do with the Powerwall install. That's nuts. If I was a solar installer, I wouldn't want to submit work I didn't have anything to do with.

*******************************************************************************************************
EDIT - WOW. Tesla redeems themselves in one nearly perfect support call.

This is insanely rare: but I called Tesla this morning and the first person I reached (after 'only' 1/2 hour of hold) didn't just say "not my department" "don't know who would handle this" (like past calls), but was able to produce a PDF showing "Authorization to Interconnect and Operate the Generating Facility" from SCE.. Still damn annoyed that nobody at Tesla returned our calls and emails for this long, but Adam (Tesla Support) had the answer in just a few minutes!

*******************************************************************************************************

Tesla still deserves some bashing, but at least not for the reason I posted here! SHAME here goes to Southern California Edison. Really seems they don't want any more solar getting installed in California, right?

 
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With solar installed behind the GW, you can still configure the PW/GW so that it doesn't know about the solar and charges from the grid. Then if you want all solar exported during Peak, and the PWs to cover all the house usage, that would require being able to position the CTs so they see all the loads without seeing the solar offset. If you instead prefer that during Peak times the PWs only offset net usage (house load - solar), then you'd need to position the CTs so that they see the net usage.

The CTs and PW configuration options are used to govern the PW behavior while on grid. During an outage, the CTs are not used, and with the PV behind the GW, it should respond normally and allow the PV to charge the PWs. I don't recall if anyone here has actually confirmed this in practice, or if it is still just my untested theoretical understanding of the system behavior.

Cheers, Wayne
 
With solar installed behind the GW, you can still configure the PW/GW so that it doesn't know about the solar and charges from the grid. Then if you want all solar exported during Peak, and the PWs to cover all the house usage, that would require being able to position the CTs so they see all the loads without seeing the solar offset. If you instead prefer that during Peak times the PWs only offset net usage (house load - solar), then you'd need to position the CTs so that they see the net usage.

The CTs and PW configuration options are used to govern the PW behavior while on grid. During an outage, the CTs are not used, and with the PV behind the GW, it should respond normally and allow the PV to charge the PWs. I don't recall if anyone here has actually confirmed this in practice, or if it is still just my untested theoretical understanding of the system behavior.

Cheers, Wayne
In your scenario with the PV on the backup side but without CT's, I wonder if the PW and GW would realize that there is a problem off grid and use the frequency shift to turn off the PV. If the PV CT's are not installed, how does the powerwall know to turn off PV. The assumption is the installer set it up as a battery backup only.

I have no idea what would happen in this case, I suspect the PW might shutdown entirely as it would be seeing an error.
 
you can still configure the PW/GW so that it doesn't know about the solar and charges from the grid. Then if you want all solar exported during Peak, and the PWs to cover all the house usage, that would require being able to position the CTs so they see all the loads without seeing the solar offset. If you instead prefer that during Peak times the PWs only offset net usage (house load - solar), then you'd need to position the CTs so that they see the net usage.

The CTs and PW configuration options are used to govern the PW behavior while on grid. During an outage, the CTs are not used, and with the PV behind the GW, it should respond normally and allow the PV to charge the PWs. I don't recall if anyone here has actually confirmed this in practice, or if it is still just my untested theoretical understanding of the system behavior.

Thanks! Not something I'd want to do repeatedly, but ; how-to-charge-powerwalls-from-grid-with-solar

Better yet: tesla-we-need-more-control-over-our-powerwalls
 
In your scenario with the PV on the backup side but without CT's, I wonder if the PW and GW would realize that there is a problem off grid and use the frequency shift to turn off the PV. If the PV CT's are not installed, how does the powerwall know to turn off PV. The assumption is the installer set it up as a battery backup only.
I am 98% sure that the PW only uses the CT information while on grid (running as a grid following inverter and trying to decide how much current to source or sink). While off grid, the PW inverters are in grid forming mode, which I think means they do their thing at lower level, the CT/Neurio/serial bus communications would probably be too slow.

I don't fully understand how a grid forming inverter works, but roughly I assume it just tries to maintain the target voltage. When loads draw more power, the voltage would drop, and the PW puts out more current. When a grid following inverter puts out power, the voltage rises, and the PW puts out less power. Including starting to charge if necessary. Then whenever it gets full, it will frequency shift to try to shutoff the grid following inverters.

This assumes that the "frequency shift when full behavior" is not dependent on having solar configured in the Wizard, but I think that's a reasonable expectation.

Cheers, Wayne
 
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miimura

Well-Known Member
Aug 21, 2013
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Los Altos, CA
I am 98% sure that the PW only uses the CT information while on grid (running as a grid following inverter and trying to decide how much current to source or sink). While off grid, the PW inverters are in grid forming mode, which I think means they do their thing at lower level, the CT/Neurio/serial bus communications would probably be too slow.

I don't fully understand how a grid forming inverter works, but roughly I assume it just tries to maintain the target voltage. When loads draw more power, the voltage would drop, and the PW puts out more current. When a grid following inverter puts out power, the voltage rises, and the PW puts out less power. Including starting to charge if necessary. Then whenever it gets full, it will frequency shift to try to shutoff the grid following inverters.

This assumes that the "frequency shift when full behavior" is not dependent on having solar configured in the Wizard, but I think that's a reasonable expectation.

Cheers, Wayne
Generally I agree with what you said here. However, there are other possible "freak-out" situations like the house exporting solar power when not configured for solar. The PWs also won't charge from solar at all, they would just charge according to their Off-Peak schedule.
 
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Generally I agree with what you said here. However, there are other possible "freak-out" situations like the house exporting solar power when not configured for solar.
If the CTs are set to only see house loads, rather than net usage (house loads minus solar), then that can't happen. But if they are set to see net usage, I agree it's an open question what the PWs would do if the GW sees negative usage, but they are not configured for solar. I would expect nothing, but it is to be verified.

The PWs also won't charge from solar at all, they would just charge according to their Off-Peak schedule.
That's certainly true, but I believe that's the behavior that the OP would prefer.

Of course, the ideal behavior (in my mind) is something the PWs don't support (but could with just software): charge from both grid and solar during off peak, keeping track of how much of the charge is from solar; during peak, push out all the solar charge to the grid, and use the grid charge to offset house loads. That would let you time shift all your usage to off peak and all your generation to peak (to the extent that you have enough PW capacity).

Cheers, Wayne
 

jboy210

Well-Known Member
Supporting Member
Dec 2, 2016
6,754
4,604
Northern California
Not to mention . . . your power company will (as in our case) almost certainly refuse to approve the next grid connected improvement if they didn't even know about the first one.

Update:
Continued SILENCE from TESLA. No response to our calls or emails about this for almost two weeks; and of course . . . multi-hour hold times trying to call anyone (support, advisers, etc). Thanks to Tesla actively ignoring me (I am not a quiet person), Edison said we should ask Semper Solaris to add the Powerwall to their approval application even though they had nothing to do with the Powerwall install. That's nuts. If I was a solar installer, I wouldn't want to submit work I didn't have anything to do with.

*******************************************************************************************************
EDIT - WOW. Tesla redeems themselves in one nearly perfect support call.

This is insanely rare: but I called Tesla this morning and the first person I reached (after 'only' 1/2 hour of hold) didn't just say "not my department" "don't know who would handle this" (like past calls), but was able to produce a PDF showing "Authorization to Interconnect and Operate the Generating Facility" from SCE.. Still damn annoyed that nobody at Tesla returned our calls and emails for this long, but Adam (Tesla Support) had the answer in just a few minutes!

*******************************************************************************************************

Tesla still deserves some bashing, but at least not for the reason I posted here! SHAME here goes to Southern California Edison. Really seems they don't want any more solar getting installed in California, right?
So are you saying Tesla filed the Authorization request years ago and SCE lost/sat on it?
 
Not to mention . . . your power company will (as in our case) almost certainly refuse to approve the next grid connected improvement if they didn't even know about the first one.

Update:
Continued SILENCE from TESLA. No response to our calls or emails about this for almost two weeks; and of course . . . multi-hour hold times trying to call anyone (support, advisers, etc). Thanks to Tesla actively ignoring me (I am not a quiet person), Edison said we should ask Semper Solaris to add the Powerwall to their approval application even though they had nothing to do with the Powerwall install. That's nuts. If I was a solar installer, I wouldn't want to submit work I didn't have anything to do with.

*******************************************************************************************************
EDIT - WOW. Tesla redeems themselves in one nearly perfect support call.

This is insanely rare: but I called Tesla this morning and the first person I reached (after 'only' 1/2 hour of hold) didn't just say "not my department" "don't know who would handle this" (like past calls), but was able to produce a PDF showing "Authorization to Interconnect and Operate the Generating Facility" from SCE.. Still damn annoyed that nobody at Tesla returned our calls and emails for this long, but Adam (Tesla Support) had the answer in just a few minutes!

*******************************************************************************************************

Tesla still deserves some bashing, but at least not for the reason I posted here! SHAME here goes to Southern California Edison. Really seems they don't want any more solar getting installed in California, right?
Yes, a great job done by Adam. Too bad he is not training the rest of the staff how to find documents.
When was it approved? Why didn't Tesla tell you that you have PTO back then? Someone dropped that ball.
I'd like to see SCE's face when you email the document they signed back then.

What a cluster f....
 

jboy210

Well-Known Member
Supporting Member
Dec 2, 2016
6,754
4,604
Northern California
Yes, a great job done by Adam. Too bad he is not training the rest of the staff how to find documents.
When was it approved? Why didn't Tesla tell you that you have PTO back then? Someone dropped that ball.
I'd like to see SCE's face when you email the document they signed back then.

What a cluster f....
Did Tesla or SCE send you anything you needed to sign for PTO? I just got an email from PG&E saying "Congratulations on investing in a renewable energy system ... " with the subject line: "Approval to turn on your Solar ..."
 
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Did Tesla or SCE send you anything you needed to sign for PTO? I just got an email from PG&E saying "Congratulations on investing in a renewable energy system ... " with the subject line: "Approval to turn on your Solar ..."
I think Tesla did but want worried or looking for it as I had solar already for many years. City passed the battery install and that is all I really needed.
PG&E may have said something.
 

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