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PG&E Customers with 3 or more PWs: Interconnection NEM2, NEM2-MT, or NEM2-PS

holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
Does this section exist in your NEMMT agreement? Section 8.1 is the insurance requirements

View attachment 637989


Yeah the most recent NEM2-MT agreement (the full one that I have yet to sign) has that 8.3 clause. But that 8.3 clause directly contradicts what I need to put on Appendix I.

One could have a ESS that derives 100% of its energy from renewable sources. If so, by the definition of the PDF that @wwhitney linked earlier, such system is a "REGF" (Renewable Electrical Generation Facility). If it is REGF, that means it cannot be grid-charged. So under Appendix I of the NEM2-MT agreement the first box must be checked to never allow grid charging under the agreement. And you're right, a homeowner need to add extra insurance under 8.1; they just need to put PG&E as a named insured under 8.2 with their standard homeowners policy.

But if the ESS can be Stormwatch enabled to take energy from the grid in an emergency, it is not REGF. Because now it can be grid charged. In this case, second check box should be used under Appendix I. But that also means 8.1 must be hoored and extra insurance added. 8.2 would still require PG&E to be named insured.

I think a reasonable interpretation is "Stormwatch" isn't a normal event. But nowhere in the docs does PG&E give a homeowner an escape clause for emergency charging.

The worst part of all of this is that all these documents punish Tesla Powerwalls because PG&E treats them as having the ability to grid-export whenever the homeowner wants. And that simply just makes this whole mess garbage.
 

MJ_CA_2019

Member
Aug 19, 2020
111
26
Central CA
Yeah the most recent NEM2-MT agreement (the full one that I have yet to sign) has that 8.3 clause. But that 8.3 clause directly contradicts what I need to put on Appendix I.

One could have a ESS that derives 100% of its energy from renewable sources. If so, by the definition of the PDF that @wwhitney linked earlier, such system is a "REGF" (Renewable Electrical Generation Facility). If it is REGF, that means it cannot be grid-charged. So under Appendix I of the NEM2-MT agreement the first box must be checked to never allow grid charging under the agreement. And you're right, a homeowner need to add extra insurance under 8.1; they just need to put PG&E as a named insured under 8.2 with their standard homeowners policy.

Somehow all the nameplate rating of my sources are listed as REGF and yet the second box on Appendix I is checked.
If you want to see this PM me and I'll get you a scrubbed copy.
 

holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
Somehow all the nameplate rating of my sources are listed as REGF and yet the second box on Appendix I is checked.
If you want to see this PM me and I'll get you a scrubbed copy.


Yeah I think I need your redacted copy... PG&E refuse to change that Appendix I checkbox. They say for my system it's 0% grid-chargeable per their NEM2-MT agreement and I don't know why they're being so goddamn stubborn.
 

holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
Wow, PG&E finally agreed to let me check the second box in Appendix I! Whoooooo.

But they still insist up and down that Tesla Powerwalls are a huge grid-exporting-risk. They won't grant me interconnection unless the 15 kW from the three Powerwalls are documented as "exporting" for my Generating Facility.

And of course I need to get the insurance. State Farm is quoting me $100 per year of extra premium to get my liability limit up to the $1,000,000 level plus add PG&E as a named insured.
 
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h2ofun

Active Member
Aug 11, 2020
2,138
332
auburn, ca
Wow, PG&E finally agreed to let me check the second box in Appendix I! Whoooooo.

But they still insist up and down that Tesla Powerwalls are a huge grid-exporting-risk. They won't grant me interconnection unless the 15 kW from the three Powerwalls are documented as "exporting" for my Generating Facility.

And of course I need to get the insurance. State Farm is quoting me $100 per year of extra premium to get my liability limit up to the $1,000,000 level plus add PG&E as a named insured.
Makes NO sense you have to say the PW's are exporting. The doc says they are NEM. Since they cannot export, and therefor, no NEM, how are they forcing you to say they are a generating item? How does this change anything though? Costs? Etc?

And what does going from first box to second box in Appendix actually change for you?
 

holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
Makes NO sense you have to say the PW's are exporting. The doc says they are NEM. Since they cannot export, and therefor, no NEM, how are they forcing you to say they are a generating item? How does this change anything though? Costs? Etc?

And what does going from first box to second box in Appendix actually change for you?


My understanding is that the entire reason we get pushed to NEM2-MT (or NEM2-PS if you're lucky) is because Powerwalls are considered grid exporting devices that PG&E manages separately from solar-only installs. Even though you and I understand that our grid export goes down with Powerwalls (we bank instead of exporting)... PG&E thinks our grid export will go up since they envision you having multiple generation sources and push energy back to PG&E in bulk during peak time.

For example; assume you were to run your generator and had a way to export that power at peak time. Do you think you'd come out ahead in terms of the cost of the gas you burned compared to the NEM credit you bank at peak? (ignoring the fact that your export may exceed your usage).

New people on NEM2-MT need the insurance since the grid-exporting batteries can possibly damage a transformer or line-side equipment. New people on NEM2-MT also have a higher interconnection fee to deal with all the extra paperwork due to their exporting Powerwalls.

The second checkbox means I can use Stormwatch without violating my NEM2-MT agreement.

Some other TMC members were moved from their old NEM2 onto NEM2-MT, so they didn't get slapped with all the extra hurdles. They were essentially grandfathered in.
 
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h2ofun

Active Member
Aug 11, 2020
2,138
332
auburn, ca
My understanding is that the entire reason we get pushed to NEM2-MT (or NEM2-PS if you're lucky) is because Powerwalls are considered grid exporting devices that PG&E manages separately from solar-only installs. Even though you and I understand that our grid export goes down with Powerwalls (we bank instead of exporting)... PG&E thinks our grid export will go up since they envision you having multiple generation sources and push energy back to PG&E in bulk during peak time.

For example; assume you were to run your generator and had a way to export that power at peak time. Do you think you'd come out ahead in terms of the cost of the gas you burned compared to the NEM credit you bank at peak? (ignoring the fact that your export may exceed your usage).

New people on NEM2-MT need the insurance since the grid-exporting batteries can possibly damage a transformer or line-side equipment. New people on NEM2-MT also have a higher interconnection fee to deal with all the extra paperwork due to their exporting Powerwalls.

The second checkbox means I can use Stormwatch without violating my NEM2-MT agreement.

Some other TMC members were moved from their old NEM2 onto NEM2-MT, so they didn't get slapped with all the extra hurdles. They were essentially grandfathered in.
Thats nuts. My generator cannot export to the Grid, And we both know the PW's cannot either. Now, I assume this is the case if there is no solar and they grid charge? Now if they can, then we are back to why cannot we do it when we have solar?
 

MJ_CA_2019

Member
Aug 19, 2020
111
26
Central CA
Thats nuts. My generator cannot export to the Grid, And we both know the PW's cannot either. Now, I assume this is the case if there is no solar and they grid charge? Now if they can, then we are back to why cannot we do it when we have solar?

For your generator you likely have an interlock to prevent backfeeding to the Grid.
PG&E may not recognize that PW hardware / software is effectively doing the same thing.
That's my attempt to explain the crazy...
 

holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
Thats nuts. My generator cannot export to the Grid, And we both know the PW's cannot either. Now, I assume this is the case if there is no solar and they grid charge? Now if they can, then we are back to why cannot we do it when we have solar?

You and I know what your generator and Powerwalls are capable of. But PG&E thinks you're going to find a way to charge your 4 Powerwalls with generator power... then export 20 kW back at peak time to game your NEM and TOU. Similarly, you could bank off-peak PG&E energy (even though you have solar) and blast that back at peak rates.

To PG&E you could be a potential problem, and they want to protect themselves from you. Which is also why they want you to carry insurance to protect them if you hurt them.
 

Vines

Active Member
Jul 20, 2018
1,870
2,185
Silicon Valley, CA
Thats nuts. My generator cannot export to the Grid, And we both know the PW's cannot either. Now, I assume this is the case if there is no solar and they grid charge? Now if they can, then we are back to why cannot we do it when we have solar?

There are many cases of PW discharging to the grid, and states where it is allowed.

All it takes is a badly placed set of CT's and you are grid exporting PW energy to the grid.
 
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holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
There are many cases of PW discharging to the grid, and states where it is allowed.

All it takes is a badly placed set of CT's and you are grid exporting PW energy to the grid.


Is it (relatively) easy to configure a Powerwall with the functionality found in other states?

My reasoning is that if PG&E forces Powerwall interconnection agreements to treat them as grid exporting, then full compliance with PG&E's own terms would accommodate Powerwalls that can grid-charge and grid export on command (within the nameplate rating and within the total net annual usage/export rules of the NEM agreement).

So technically all those extra fees, insurance requirements, imposed by PG&E are offset if a homeowner could use the Powerwalls to the full potential that PG&E is protecting for.

I guess technically there is still the SGIP and Federal ITC to contend with; but I'm just focusing on the NEM2-MT agreement for this thought exercise.
 

h2ofun

Active Member
Aug 11, 2020
2,138
332
auburn, ca
There are many cases of PW discharging to the grid, and states where it is allowed.

All it takes is a badly placed set of CT's and you are grid exporting PW energy to the grid.
So sounds like if one has their CTs setup such that it thinks their PW is solar, then I guess it go back to the grid. And I guess some would do this. Just not worth the hassle, IMO. But, ....
 

h2ofun

Active Member
Aug 11, 2020
2,138
332
auburn, ca
Is it (relatively) easy to configure a Powerwall with the functionality found in other states?

My reasoning is that if PG&E forces Powerwall interconnection agreements to treat them as grid exporting, then full compliance with PG&E's own terms would accommodate Powerwalls that can grid-charge and grid export on command (within the nameplate rating and within the total net annual usage/export rules of the NEM agreement).

So technically all those extra fees, insurance requirements, imposed by PG&E are offset if a homeowner could use the Powerwalls to the full potential that PG&E is protecting for.

I guess technically there is still the SGIP and Federal ITC to contend with; but I'm just focusing on the NEM2-MT agreement for this thought exercise.
Interesting. When I did solar, PGE agreed how much I could export. So, are they now adding the batteries to this backfeed amount? How much would it be?
 

holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
Interesting. When I did solar, PGE agreed how much I could export. So, are they now adding the batteries to this backfeed amount? How much would it be?


Here's the section 2.7 (power that can be exported) that PG&E made me include in my signed NEM2-MT form.

The solar AC kW is measured as 23 Enphase IQ7+ Microinverters which peak at 1.21A each. 23 x 1.21A x 240v = 6.679 kW max coming from solar that could back feed PG&E. Each of the 3 Powerwalls is 5 kW peak back feed. PG&E adds them all together and says in the absolute worst case scenario, I can back feed 21.670 kW. This 21.670 kW is scary to them... it can damage their equipment and be used to game their NEM/TOU.

The stupidest part of all this is that PG&E's design/planning team also believed I could export this full amount while my house loads simultaneously took 200A (presumably 48 kW) from them.

It drove me nuts because they insisted the 3x Powerwalls had to be included in the 120 percent rule calculation (instead of just the normal calc where only the solar portion has to fit in the 120 percent rule). Ultimately they made Sunrun add specific language to the permit. (per this thread)

No joke, PG&E wanted me to limit my home loads to 125A... 125A of home loads + 90A of grid export could be supported by a 200A MSP with 120% rule.



upload_2021-2-23_13-14-21.png
 
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h2ofun

Active Member
Aug 11, 2020
2,138
332
auburn, ca
Here's the section 2.7 (power that can be exported) that PG&E made me include in my signed NEM2-MT form.

The solar AC kW is measured as 23 Enphase IQ7+ Microinverters which peak at 1.21A each. 23 x 1.21A x 240v = 6.679 kW max coming from solar that could back feed PG&E. Each of the 3 Powerwalls is 5 kW peak back feed. PG&E adds them all together and says in the absolute worst case scenario, I can back feed 21.670 kW. This 21.670 kW is scary to them... it can damage their equipment and be used to game their NEM/TOU.

The stupidest part of all this is that PG&E's design/planning team also believed I could export this full amount while my house loads simultaneously took 200A (presumably 48 kW) from them.

It drove me nuts because they insisted the 3x Powerwalls had to be included in the 120 percent rule calculation (instead of just the normal calc where only the solar portion has to fit in the 120 percent rule). Ultimately they made Sunrun add specific language to the permit. (per this thread)



View attachment 639297
That is instantaneous. Great. But I was talking about the yearly total that can be done. We have seen the one person who PGE has recorded a much smaller solar setup than he really has. So when he exports more than the magic number for the smaller on record, he gets no cost credits. So, same question for your "generation facility" Seems they now have agreed in writing, you can export your solar AND batteries, just not exceeding 21.6kw at a time. But, how much can you get credit for per month, per year From what you were forced to sign, sure seems there is nothing legally wrong now having CT's placed in a way you can export, since you have a signed contract with PGE saying it is okay. And I do not remember seeing any limits to how and where you get the energy to charge your PW's
 

holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
That is instantaneous. Great. But I was talking about the yearly total that can be done. We have seen the one person who PGE has recorded a much smaller solar setup than he really has. So when he exports more than the magic number for the smaller on record, he gets no cost credits. So, same question for your "generation facility" Seems they now have agreed in writing, you can export your solar AND batteries, just not exceeding 21.6kw at a time. But, how much can you get credit for per month, per year From what you were forced to sign, sure seems there is nothing legally wrong now having CT's placed in a way you can export, since you have a signed contract with PGE saying it is okay. And I do not remember seeing any limits to how and where you get the energy to charge your PW's


Oh my bad, you were talking about annual kWh import/export. I thought you meant what was the info specific to NEM2-MT. The NEM2-MT doesn't actually talk about annual usage/export assessments and annual net metering.

I believe your question is covered in how PG&E enforces the base NEM2 agreement. You should have signed something already that includes language similar to the following picture.

My understanding is that at its core... PG&E is going to look at the NEM2-MT situation similar to how they would assess a normal NEM2 situation. If your house used 12,000 kWh in a year then suddenly you export 20,000 kWh; they're not going to give you credits for the extra export unless you can explain things (good luck with that) to justify the changes to your usage/export.

Similarly, I think PG&E is allowed to make overriding decisions if your usage shoots up (as you grid-charged your Powerwalls during off peak)... and then your exports also shoot up (as you push energy back at peak time).

I tried to access that "greenbutton" link and I get a 403 error.


upload_2021-2-23_13-40-26.png
 

h2ofun

Active Member
Aug 11, 2020
2,138
332
auburn, ca
Oh my bad, you were talking about annual kWh import/export. I thought you meant what was the info specific to NEM2-MT. The NEM2-MT doesn't actually talk about annual usage/export assessments and annual net metering.

I believe your question is covered in how PG&E enforces the base NEM2 agreement. You should have signed something already that includes language similar to the following picture.

My understanding is that at its core... PG&E is going to look at the NEM2-MT situation similar to how they would assess a normal NEM2 situation. If your house used 12,000 kWh in a year then suddenly you export 20,000 kWh; they're not going to give you credits for the extra export unless you can explain things (good luck with that) to justify the changes to your usage/export.

Similarly, I think PG&E is allowed to make overriding decisions if your usage shoots up (as you grid-charged your Powerwalls during off peak)... and then your exports also shoot up (as you push energy back at peak time).

I tried to access that "greenbutton" link and I get a 403 error.


View attachment 639313
Again, not the question. When we filled out the paper work for my house, there were 2 calculations One was based on size of house. And one was based on my last 12 months usage. My last 12 months was HUGE because I had no heating systems. So, as show below on my PGE form, I have a lot more, and a lot more, generation I can do to handle what the 12 month data given to them is. (I wonder if they ever have seen a negative before, let alone that large)..

So, IMO, this would imply I can add another 20K KWH and still be within the numbers? Must more I assume would cap on the PV number for the year, since it would be equal or larger than there use?
 

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holeydonut

Supporting Member
Jun 27, 2020
1,275
769
East Bay NorCal
Again, not the question.


Lol I guess I don't know what you're trying to get answered then. The picture you posted should be the one found on the normal NEM2 agreement. I assume you actually signed a part (or all) of that agreement where you took the picture from?

My concern based on what you showed is that you basically attested to PG&E that your upcoming PV system is sized to be 1/2 of your recent annual usage. So it's possible you created a baseline that you will be a net-consumer to the tune of 20,000 kWh on an annual basis.

I really don't know how they enforce their NEM2 rules. It'd be great if they let you operate anywhere from negative 20,000 kWh to zero. But I'd imagine if you somehow became a net positive in their eyes (produced more than you used)... they're going to come at you to accuse you of trying to game the NEM.
 

wwhitney

Member
Nov 2, 2017
822
1,039
Berkeley, CA
It drove me nuts because they insisted the 3x Powerwalls had to be included in the 120 percent rule calculation (instead of just the normal calc where only the solar portion has to fit in the 120 percent rule).
For what it's worth, that's actually correct, as far as the 2017 NEC, in force in California. It is only with 2020 NEC and its recognition of Power Control Systems that you wouldn't have to consider the Powerwall inverters.

But usually it's moot, as the the main disconnect is just a 200A feeder (any other breakers are removed), so the 120% ruled doesn't apply there. And the feeder topology is arranged so that there are no panels subject to the 120% rule. Are you sure it wasn't just that PG&E was misunderstanding the alternatives to the 120% rule?

Cheers, Wayne
 

Vines

Active Member
Jul 20, 2018
1,870
2,185
Silicon Valley, CA
Is it (relatively) easy to configure a Powerwall with the functionality found in other states?

My reasoning is that if PG&E forces Powerwall interconnection agreements to treat them as grid exporting, then full compliance with PG&E's own terms would accommodate Powerwalls that can grid-charge and grid export on command (within the nameplate rating and within the total net annual usage/export rules of the NEM agreement).

So technically all those extra fees, insurance requirements, imposed by PG&E are offset if a homeowner could use the Powerwalls to the full potential that PG&E is protecting for.

I guess technically there is still the SGIP and Federal ITC to contend with; but I'm just focusing on the NEM2-MT agreement for this thought exercise.

I do not know directly, but I think it only requires an interconnection agreement that allows ESS energy to be exported and the software to match. No other hardware changes need to happen.
 

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