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PG&E discrepancy between amount exported to grid and amount credited to NEM

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Zorg

Active Member
Oct 24, 2017
2,541
2,387
Fremont, ca
I apologize if it's been discussed but here it goes.

I had a solar system installed in 2014. In 2020, I had 2 Powerwalls installed. Earlier this year, I got my PTO for an expansion of my solar system. When looking at the detail bill for my NEM, I see the following issue for my latest bill, under the "PAIRED STORAGE MAXIMUM EXPORT ESTIMATION":

Exported to the grid: -751 KWh
Estimated PV generation: -562KWh

In the NEM summary, PGE is using 562KWh as my credited production. PG&E is basically deducting 25% of my solar export to the grid every month.

I called PG&E and talked to a rep, and to the supervisor, neither of which could explain the discrepancy. I was supposed to talk to the next level supervisor, but they hung up on me.

I'm suspecting that they did their calculation incorrectly, or using my old system, but before I invest another 2 hours trying to get the hold of someone, I figured I would tap in the collective experience of this group to see if this is normal. BTW, the supervisor told me that this estimated production is based on the production as estimated by CSI EPBB Calculator
 
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I apologize if it's been discussed but here it goes.

I had a solar system installed in 2014. In 2020, I had 2 Powerwalls installed. Earlier this year, I got my PTO for an expansion of my solar system. When looking at the detail bill for my NEM, I see the following issue for my latest bill, under the "PAIRED STORAGE MAXIMUM EXPORT ESTIMATION":

Exported to the grid: -751 KWh
Estimated PV generation: -562KWh

In the NEM summary, PGE is using 562KWh as my credited production. PG&E is basically deducting 25% of my solar export to the grid every month.

I called PG&E and talked to a rep, and to the supervisor, neither of which could explain the discrepancy. I was supposed to talk to the next level supervisor, but they hung up on me.

I'm suspecting that they did their calculation incorrectly, or using my old system, but before I invest another 2 hours trying to get the hold of someone, I figured I would tap in the collective experience of this group to see if this is normal. BTW, the supervisor told me that this estimated production is based on the production as estimated by CSI EPBB Calculator
Did PGE approve the number/size of panels you have now?
 
I apologize if it's been discussed but here it goes.

I had a solar system installed in 2014. In 2020, I had 2 Powerwalls installed. Earlier this year, I got my PTO for an expansion of my solar system. When looking at the detail bill for my NEM, I see the following issue for my latest bill, under the "PAIRED STORAGE MAXIMUM EXPORT ESTIMATION":

Exported to the grid: -751 KWh
Estimated PV generation: -562KWh

In the NEM summary, PGE is using 562KWh as my credited production. PG&E is basically deducting 25% of my solar export to the grid every month.

I called PG&E and talked to a rep, and to the supervisor, neither of which could explain the discrepancy. I was supposed to talk to the next level supervisor, but they hung up on me.

I'm suspecting that they did their calculation incorrectly, or using my old system, but before I invest another 2 hours trying to get the hold of someone, I figured I would tap in the collective experience of this group to see if this is normal. BTW, the supervisor told me that this estimated production is based on the production as estimated by CSI EPBB Calculator

I have read in another thread in this section (dont remember exactly which one), that PGE will only credit you for no more than whatever they estimate your system will produce. You mention right there in your opening post, that you exported 751 kwh, but they estimate that the system size (PV size) of your permitted system will generate no more than 562 kWh, so thats all they are going to give you credit for.

That means to me, that either the paperwork has not "caught up with itself" for your PTOed new system, or that your new system doesnt have PTO yet, or that PGE has messed up somewhere in connecting your new system to your account in some way.

@arnolddeleon has (or had) a problem like that with PGE, with more than one system, and not receiving proper credit for it.

I am not in PGE land (SCE where I live), but if PTO for "expansion of your PV system" means you got new solar / PV to go along with existing solar / PV (so now you have 2 separate PV systems and your powerwalls), you should start with PGE there.
 
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I apologize if it's been discussed but here it goes.

I had a solar system installed in 2014. In 2020, I had 2 Powerwalls installed. Earlier this year, I got my PTO for an expansion of my solar system. When looking at the detail bill for my NEM, I see the following issue for my latest bill, under the "PAIRED STORAGE MAXIMUM EXPORT ESTIMATION":

Exported to the grid: -751 KWh
Estimated PV generation: -562KWh

In the NEM summary, PGE is using 562KWh as my credited production. PG&E is basically deducting 25% of my solar export to the grid every month.

I called PG&E and talked to a rep, and to the supervisor, neither of which could explain the discrepancy. I was supposed to talk to the next level supervisor, but they hung up on me.

I'm suspecting that they did their calculation incorrectly, or using my old system, but before I invest another 2 hours trying to get the hold of someone, I figured I would tap in the collective experience of this group to see if this is normal. BTW, the supervisor told me that this estimated production is based on the production as estimated by CSI EPBB Calculator

On page 3 of your B&W DOB you'll find this:

Capture.PNG


What does this say for your B&W bill?

Note, they estimate my maximum to be 1232 but the actual was 1755 for the same 32 days of service. The CSI EPBB tool they use to calculate the estimate says 1351. I compared the information on the interconnection agreement application and it matches the actual system in every way so they either entered data by mistake into CSI EPBB OR they are screwing us and this is eventually going to come to light when enough people fill out the PUC complaint form which I've just done. I filled out the format because even if they fix it which they'd better, the reason for it being wrong in first place needs to be investigated. I'll bet not a single customer has the correct estimated value even close to what it should be. CSI EPBB is already gamed to be way way under actual production. PG&E says 1232. CSI EPBB says 1351 and actual is 1755.

Capture.PNG


It took 4 weeks, 18 emails, and 5 phone conversations to eventually convince them that it was wrong. That was 2 weeks ago and they said they'd look into. Haven't heard anything back yet.
 
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On page 3 of your B&W DOB you'll find this:

View attachment 679026

What does this say for your B&W bill?

Note, they estimate my maximum to be 1232 but the actual was 1755 for the same 32 days of service. The CSI EPBB tool they use to calculate the estimate says 1351. I compared the information on the interconnection agreement application and it matches the actual system in every way so they either entered data by mistake into CSI EPBB OR they are screwing us and this is eventually going to come to light when enough people fill out the PUC complaint form which I've just done. I filled out the format because even if they fix it which they'd better, the reason for it being wrong in first place needs to be investigated. I'll bet not a single customer has the correct estimated value even close to what it should be. CSI EPBB is already gamed to be way way under actual production. PG&E says 1232. CSI EPBB says 1351 and actual is 1755.

View attachment 679032

It took 4 weeks, 18 emails, and 5 phone conversations to eventually convince them that it was wrong. That was 2 weeks ago and they said they'd look into. Haven't heard anything back yet.
that's interesting. I don't have a Table with the "Estimated PV Generation". Instead of the Estimated, I have "Metered Generation". When I got my 3 PWs, they made me put in a meter dedicated to the PV generation. So they know I'm not exporting more than I generate.
 
that's interesting. I don't have a Table with the "Estimated PV Generation". Instead of the Estimated, I have "Metered Generation". When I got my 3 PWs, they made me put in a meter dedicated to the PV generation. So they know I'm not exporting more than I generate.

If they made you put in an NGOM, then they can't cap your exported solar unless your system is larger than what they approved.

NGOMs are pricey. How long ago did you get your system installed? They haven't required NGOMs for a while now but you still have the option to use one instead of the estimation methodologies as long as you pay for it out of your own pocket.
 
Thanks for the answers. Additional solar was approved and I received PTO from PGE on 2/2/21. So, it's all on the up and up (there's another long story how I got there, but it's irrelevant to this). Additionally, with the new panels, they're supposed to put me on TOU-C, and I'm still on E6...

@sorka, is the "estimated PV generation" supposed to equal the max generation possible under the csi-epbb calculator? If so, that number should always exceed the amount sent back to the grid since I always consume most of my production. Any idea who to e-mail? Customer service was useless, nice but useless.
 
If they made you put in an NGOM, then they can't cap your exported solar unless your system is larger than what they approved.

NGOMs are pricey. How long ago did you get your system installed? They haven't required NGOMs for a while now but you still have the option to use one instead of the estimation methodologies as long as you pay for it out of your own pocket.

PWs installed in Jan 2020, but did not get PTO until May. Install company (not Tesla) left them on, so I did not turn them off before PTO. I actually did upgrade my PV from 8.85 kW to 11.8 kW 6 months before the PW install. Found out that Installers never got approval from PG&E, but I've never had an issue. Probably because my roof in E/W and more than half of the panels are facing E and I kept the same inverter with the new PV. I max out at about 7.6 kW.
 
No NGOM as I fell in the small NEM paired storage exemption

But if you have a dedicated meter that measures your solar output that PG&E reads, then that IS a Net Generation Output Meter.

If not, then they use CSI EPBB to estimate your solar production except that they're apparently not since you said you don't have the "estimated output" box on your B&W bill.

You should contact the PG&E solar customer number and open a case.
 
But if you have a dedicated meter that measures your solar output that PG&E reads, then that IS a Net Generation Output Meter.

If not, then they use CSI EPBB to estimate your solar production except that they're apparently not since you said you don't have the "estimated output" box on your B&W bill.

You should contact the PG&E solar customer number and open a case.

I do have the estimated output box ("Estimated PV generation" box on page 3 of the detailed bill). I'll call PGE customer service again, but that's going to be a painful discussion. Thanks.
 
I do have the estimated output box ("Estimated PV generation" box on page 3 of the detailed bill). I'll call PGE customer service again, but that's going to be a painful discussion. Thanks.
The key point you need to establish when you talk to them is what your solar equipment inventory is in their system. When you apply for Interconnection, the specific panels, installation orientation, and inverters are specified. This inventory is used for the production estimation. The problem @arnolddeleon has is that when he added additional solar + Powerwall, PG&E lost the records of his original solar system. His production estimation is only based on his newer solar systems.
 
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What maybe important here is how with the NEM agreement form filled out? I had an install of 15K. Now I added another 15K from another installed. when I signed the NEM form for PGE, it included ALL the panels, not just the new ones.
 
I checked the PTO e-mail from PG&E and they list all 26 panels and micro inverters, as well as the 2 PWs. However, my understand is that a separate team computes the estimated PV production. So, for all I know that team used only the new panels only. Either way, I have to get through to somebody who can fix this. That should be fun. For now, I sent an e-mail to the NEM team.