PG&E NEM2PS True-Up Calculation?

[swedge]

I recently received my first NEM2 true-up. It seems to be following a rule different from those described in NEM-PS Annual True-Up Calculation [PG&E example]

I'm putting this in a new thread so as not to confuse the excellent explanation it the post linked above. If my true-up implies changes are needed in that post, the time to do that would be after this one is sorted out.

I have ferreted out the calculation that was done in my true-up, so I do understand the arithmetic. What I would like some help on is fiuguing out if this different rule makes sense.

Here is the information from my B&W True-Up statement, following the format in the post above:

Minimum Charges – ($10.90)
NEM True-Up Adjustment – ($67.43)
Energy Commission Tax – ($.83)
Electric Utility User Tax - ($5.87) (I think this is a county tax)
Total Current Month's Electric Charges Due – ($85.03)

(Don't get me wrong, this low amount is better than I had hoped!)

Cumulative Energy Charges or Credits – ($356.87)
Cumulative Non-Bypassable Charges – ($191.49)
Previous Billed Amounts – ($124.06)

So, this would seem to match Case 1 in aesculus post.

Case 1 - Cumulative Total Charges or Credits ($356.87) is greater or equal to the Cumulative Non-Bypassable Charges ($191.49): This is true in my case. Now I'll substitute my numbers in the posted calculation:

In this case you pay the Cumulative Total Charges or Credits ($356.87) minus the Previous Billed Amount ($124.06) plus the unpaid Minimum Charges ($10.90) from the current month which equals $243.71. Now since PG&E likes to make things confusing to the reader, they split out the Energy Commission Tax of $.83 (and my Utility Tax of $5.87) from Cumulative Total Charges or Credits which gets you the numbers in the first table.

• Minimum Charges – ($10.90)
• NEM True-Up Adjustment – ($231.98) = ($356.87 - $.83 - $124.06)
• Energy Commission Tax – ($.83)
• Utility Tax - ($5.87)
• Total Current Month's Electric Charges Due – ($243.71) = ($10.90 + $231.98 + $.83 + $ 5.87)

The problem is that $243.71 is not what PG&E came up with. PG&E said it was $85.03! It is not like them to under bill...

The difference lies in the NEM True-Up adjustment. Where the post used the Cumulative Total Charges or Credits (which makes complete sense), on mine PG&E instead used the the lower Cumulative Non-Bypassable Charges – ($191.49). This minus the Previously Billed Amounts ($124.06) equals $67.43 for the NEM True-Up Adjustment, and hence the $$85.02 total due:

• Minimum Charges – ($10.90)
• NEM True-Up Adjustment – ($67.43) = ($191.49 - $124.06)
• Energy Commission Tax – ($.83)
• Utility Tax - ($5.87)
• Total Current Month's Electric Charges Due – ($85.03) = ($10.90 + $67.43 + $.83 + $ 5.87)

So, why did the use they, in effect, charge me only the NBC's rather than the total cumulative charges? There are some rather cryptic notes on page 10 of the B&W bill which appear to call this an "NBC TRUE-UP" due to two factors. First, the NBC's are greater than the Minimum Delivery Charges (the $124.06 Previously Billed), and second, the non-NBC charges excluding the generation charges and credits was less than zero. By way of explanation, the Cumulative Energy Charges or Credits is broken out into NBC (191.49) and Non-NBC (165.38) amounts which sum to ($356.87). Then the Generation charge and Generation Credit are deducted. This sums to minus 82.53, i.e. less than zero.

OK, so that is PG&E's explanation of "why" they did this, but I don't see the logic behind this.

I see a phrase in the NEM2 tariff (S.C.2,h) which says that if the net generation charges are less than zero, the credit will not be applied. That might explain it, but in my case , the generation charges exceeded the credits by $247.91, so this would not seem to apply.

Any ideas?

Thanks!
SW

 

[miimura]

I agree with your assessment. When your Cumulative Energy Charges are greater than the Cumulative Non-Bypassable Charges, the true-up should ignore the Non-Bypassable Charges and base the calculation on the Energy Charges.

Just to be clear, you are on total PG&E billing and there is no CCA in the picture, right?

 

[swedge]

Thank you for looking at it!

Just to be clear, you are on total PG&E billing and there is no CCA in the picture, right?

That is right, pure PG&E, no CCA.

I agree with your assessment. When your Cumulative Energy Charges are greater than the Cumulative Non-Bypassable Charges, the true-up should ignore the Non-Bypassable Charges and base the calculation on the Energy Charges.

My Cumulative Energy Charges were $247.08, i.e. greater than the NBCs of 191.49. So you say the True-Up should ignore the NBCs. But my true up was based on the NBC's, specifically the NBCs minus the Previously Billed Amounts. So the NBC's were all that was paid, plus some taxes that is.

That is to say, they did not follow the rule you describe.

Any idea why?

As I've dug through this, I tried to find the Cumulative Energy Charges rule in the NEM2 and EV2 tariffs. Do you know where that rule came from?

Thanks agin for lending a hand on this,
SW

 

[swedge]

I spoke with PG&E solar support, asking for an explanation of why my true-up was so low. (See my original post in this thread). Tha agent said she had never seen a situation like this before. She spent quite a while searching through her training material and found an explanation. She said she could not give me a copy, but verbally described it as follows:

The NBC True-Up will be used whenever either of the following is true:​

• Cumulative Non-Bypassable Charges are more than Cumulative Energy Charges, or
• Cumulative Non-Bypassable Charges are more then the Cumulative Minimum Delivery Charges.

In my case, the NBCs were less than the Energy charges, so that did not apply.

However, my NBC's were greater than my Minimum Delivery Charges.

Hence, the NBC true-up, wherein the True-Up Adjustment was the NBC's minus the Minimum Delivery Charges.

I am finding no justification for this in the EV2-A rate schedule nor in the NEM2 Tariff. But the agent assured me that it was not a mistake, and my true-up was consistent with this inexplicable rule.

If anyone is willing to share their PG&E NEM2 solar plus storage black and white bill with me, I would appreciate it. I am trying to confirm the conditions which trigger the various true-up adjustments. This was my first, and it differs from what was described in NEM-PS Annual True-Up Calculation [PG&E example].

We designed our solar + PowerWall to minimize our utility costs. PG&E charges a monthly minimum and after a full year apply a true-up adjustment to account for the net costs and credits from our consumption and generation through the year. Our design objective was to get the adjustment as close to zero as we could. But to do this in advance, we need to know how PG&E determines the adjustment. We thought we understood that it would be based on the Cumulative Energy Charges or the NBCs, or the Minimum Energy Charges, whichever is larger. In our case the NBC's were larger, so we expected that. But they used the smaller NBC's instead. Cool, we paid less, but uncool because we don't know why. Can we expect the same again on the next true-up? What do I need to do to get the same treatment again? It remains a mystery...

My true-up was only $165 less than I expected. Not a big deal. But when the rates are calculated down to one one-thousandth of a penny, this is a whopping delta.

 

[h2ofun]

I spoke with PG&E solar support, asking for an explanation of why my true-up was so low. (See my original post in this thread). Tha agent said she had never seen a situation like this before. She spent quite a while searching through her training material and found an explanation. She said she could not give me a copy, but verbally described it as follows:

The NBC True-Up will be used whenever either of the following is true:​

• Cumulative Non-Bypassable Charges are more than Cumulative Energy Charges, or
• Cumulative Non-Bypassable Charges are more then the Cumulative Minimum Delivery Charges.

In my case, the NBCs were less than the Energy charges, so that did not apply.

However, my NBC's were greater than my Minimum Delivery Charges.

Hence, the NBC true-up, wherein the True-Up Adjustment was the NBC's minus the Minimum Delivery Charges.

I am finding no justification for this in the EV2-A rate schedule nor in the NEM2 Tariff. But the agent assured me that it was not a mistake, and my true-up was consistent with this inexplicable rule.

If anyone is willing to share their PG&E NEM2 solar plus storage black and white bill with me, I would appreciate it. I am trying to confirm the conditions which trigger the various true-up adjustments. This was my first, and it differs from what was described in NEM-PS Annual True-Up Calculation [PG&E example].

We designed our solar + PowerWall to minimize our utility costs. PG&E charges a monthly minimum and after a full year apply a true-up adjustment to account for the net costs and credits from our consumption and generation through the year. Our design objective was to get the adjustment as close to zero as we could. But to do this in advance, we need to know how PG&E determines the adjustment. We thought we understood that it would be based on the Cumulative Energy Charges or the NBCs, or the Minimum Energy Charges, whichever is larger. In our case the NBC's were larger, so we expected that. But they used the smaller NBC's instead. Cool, we paid less, but uncool because we don't know why. Can we expect the same again on the next true-up? What do I need to do to get the same treatment again? It remains a mystery...

My true-up was only $165 less than I expected. Not a big deal. But when the rates are calculated down to one one-thousandth of a penny, this is a whopping delta.

I get my true up this month. You need a true up bill or just any bill?

 

[swedge]

I get my true up this month. You need a true up bill or just any bill?

True-up, black and white "detailed bill" ! That is where they do stuff that they refuse to explain. You can get the .pdf of the B&W bill from you online PG&E account. Mine was 16 pages, too much to scan, and the paper copy arrived a month after the "regular" bill was due. Yours will have way bigger numbers than mine... Or, as PG&E will never say to you, "Thank you for your support!" SW

 

[h2ofun]

True-up, black and white "detailed bill" ! That is where they do stuff that they refuse to explain. You can get the .pdf of the B&W bill from you online PG&E account. Mine was 16 pages, too much to scan, and the paper copy arrived a month after the "regular" bill was due. Yours will have way bigger numbers than mine... Or, as PG&E will never say to you, "Thank you for your support!" SW

Will contact you when I get, or your bug me if I forget. Should be a week or so

 

[miimura]

Both the Net Energy Charges and the Non-Bypassable Charges should deduct the Minimum Delivery Charges already paid. However, the “correct” adjustment to be applied should be the larger of those two differences. PG&E seems to have a logic error in their billing system. Nice that it worked in your favor this time.

 

[swedge]

Both the Net Energy Charges and the Non-Bypassable Charges should deduct the Minimum Delivery Charges already paid. However, the “correct” adjustment to be applied should be the larger of those two differences.

That is my understanding as well. There is one additional possible adjustment (which I have seen on prior true-ups) based on "Minimum Energy Charges" if those are positive. When the Net Energy Charges (formerly called NEM charges) are less than the sum of the Minimum Energy Charges and the Minimum Delivery Charges, then true-up adjustment will be the Minimum Energy Charges. So that sum of Minimum Energy Charges plus Minimum Deliver Charges is a third amount, which if largest becomes the basis of the adjustment.

PG&E seems to have a logic error in their billing system. Nice that it worked in your favor this time.

That was my first thought, but since the agent found in their (secret) documentation an "explanation" of the calculation used in my bill , it seems that there is more than just the billing logic that is odd. I wonder if maybe there was some litigation around ambiguities in the EV2-A and NEM2 tariffs which resulted in this wrinkle. Who knows?

I am asking friends with similar systems (PG&E, NEM2, solar plus battery) to let me study their true-up bill, to see if they got the same favorable but inexplicable treatment.

 

[Redhill_qik]

That is my understanding as well. There is one additional possible adjustment (which I have seen on prior true-ups) based on "Minimum Energy Charges" if those are positive. When the Net Energy Charges (formerly called NEM charges) are less than the sum of the Minimum Energy Charges and the Minimum Delivery Charges, then true-up adjustment will be the Minimum Energy Charges. So that sum of Minimum Energy Charges plus Minimum Deliver Charges is a third amount, which if largest becomes the basis of the adjustment.

That was my first thought, but since the agent found in their (secret) documentation an "explanation" of the calculation used in my bill , it seems that there is more than just the billing logic that is odd. I wonder if maybe there was some litigation around ambiguities in the EV2-A and NEM2 tariffs which resulted in this wrinkle. Who knows?

I am asking friends with similar systems (PG&E, NEM2, solar plus battery) to let me study their true-up bill, to see if they got the same favorable but inexplicable treatment.

I'm having a hard time with trying to follow your numbers as I can't tell what is positive and what is negative. Can you please post these two tables from your black-and-white bill.

• NBC and non-NBC Components.
  
• True-up Evaluation and True-Up Adjustment
• 

 

[swedge]

I'm having a hard time with trying to follow your numbers as I can't tell what is positive and what is negative. Can you please post these two tables from your black-and-white bill.

• NBC and non-NBC Components.
• True-up Evaluation and True-Up Adjustment

Redhill, Thank you for taking a look at this, and also for posting your more normal (and delightfully zero) true-up adjustment tables.

I'm including the front page summaries from the B&W as well, showing the odd-ball adjustment number.

 

[Redhill_qik]

Redhill, Thank you for taking a look at this, and also for posting your more normal (and delightfully zero) true-up adjustment tables.

I'm including the front page summaries from the B&W as well, showing the odd-ball adjustment number.

View attachment 957433

View attachment 957434

View attachment 957441

It looks like your Generation charges and credits were zero'ed out and this might be a NEM rule if you exported more than you imported. What does this table look like on your bill:

Also, what tariff/rate are you on (E-TOU-C, E-TOU-D, EV2A)?

 

[swedge]

It looks like your Generation charges and credits were zero'ed out and this might be a NEM rule if you exported more than you imported. What does this table look like on your bill:

View attachment 957536

Also, what tariff/rate are you on (E-TOU-C, E-TOU-D, EV2A)?

Red,

Thank you again for taking a look at this.

My imports were more than exports, see attachment, so was not a net generator.

I am on EV2-A.

To be clear, I am happy with the way they calculated the true-up, but the NBC true-up was less than what I calculated based on the TMC posts about true-up as well as NEM2 and EV2A tariffs. I'm not complaining about the amount, just trying to understand why PG&E did what they did.

 

[Redhill_qik]

Red,

Thank you again for taking a look at this.

My imports were more than exports, see attachment, so was not a net generator.

I am on EV2-A.

To be clear, I am happy with the way they calculated the true-up, but the NBC true-up was less than what I calculated based on the TMC posts about true-up as well as NEM2 and EV2A tariffs. I'm not complaining about the amount, just trying to understand why PG&E did what they did.

View attachment 957624

Sorry to be a pest, but that table isn't the same one that I was looking. Can you grab the "NEM TRUE-UP HISTORY - SUMMARY TOTALS" table from the last two pages on the bill.

What did your PG&E Blue bill look like? Did it only have a charge for $85.03 or did that add in your generation charges?

 

[swedge]

Sorry to be a pest, but that table isn't the same one that I was looking. Can you grab the "NEM TRUE-UP HISTORY - SUMMARY TOTALS" table from the last two pages on the bill.

What did your PG&E Blue bill look like? Did it only have a charge for $85.03 or did that add in your generation charges?

Oops, sorry. No worries about pestering, I truly appreciate your attempt to untangle this one - Iv'e been at it, scratching my head for a month. I'm bald now. To paraphrase from Amadeus, too many tables! The one you actually requested is attached below.

My blue bill charged me $85.03, consistent with the B&W jungle of numbers.

Thank you, yet again!
SW

 

[Redhill_qik]

Oops, sorry. No worries about pestering, I truly appreciate your attempt to untangle this one - Iv'e been at it, scratching my head for a month. I'm bald now. To paraphrase from Amadeus, too many tables! The one you actually requested is attached below.

My blue bill charged me $85.03, consistent with the B&W jungle of numbers.

It just doesn't make any sense at all. The two biggest items that stand out to me are

• Distribution is negative (-$230.87), but transmission is positive ($138.06) and generation is positive ($247.08)
• The net generation is positive, but it was zero'ed out for the calculation and the net generation kWh is also positive

I can't wrap my head around how your distribution could be negative with the other two positive. Do you only draw from the grid during Off-Peak and maybe are using the Export Everything during Peak? Since EV2 Off-Peak distribution rate is only about 20% of the Part-Peak and Peak rates, I could maybe see that going negative. Then my next best guess is that a programmer made a mistake/simplification that made you a Net Generator and that zero'ed out the Generation Charge/Credit calculation.

Could any other NEM 2.0 and EV2A non-CCA users share their recent true-up tables?

 

[swedge]

It just doesn't make any sense at all.

My thought exactly. Hence this thread. Thank you for double checking my incredulity.

The two biggest items that stand out to me are

• Distribution is negative (-$230.87), but transmission is positive ($138.06) and generation is positive ($247.08)
• The net generation is positive, but it was zero'ed out for the calculation and the net generation kWh is also positive

I'll look into why those came out that way. But I agree that their evaluation ignored the generation charges and credits, and I still don't see why. That does not appear to match the logic the PG&E agent described to me either.

I can't wrap my head around how your distribution could be negative with the other two positive. Do you only draw from the grid during Off-Peak and maybe are using the Export Everything during Peak?

That is what I've done for much of the year. I now wish I had let SGIP buy me two PowerWalls instead of "only" one, so I could time shift all of my solar during peak periods. That would help PG&E too.

Since EV2 Off-Peak distribution rate is only about 20% of the Part-Peak and Peak rates, I could maybe see that going negative.

My next deep dive will be to disentangle the various factors in my usage which got me here. I see yet another excel spreadsheet in my future... The hard part is knowing if and when PG&E will use this (probably wrong) rule in the future.

Then my next best guess is that a programmer made a mistake/simplification that made you a Net Generator and that zero'ed out the Generation Charge/Credit calculation.

Hmmm. Interesting thought. However the support agent I spoke with described a rule comparing the NBCs with the Minimum Delivery Charges (already paid) and with the Energy Charges (presumably the NEM charges, aka Cumulative Energy Charges or Credits). If NBC are larger than either of these, then NBC's are the True-Up basis. This is what they did in mine. Perhaps that logic should have been an .AND. rather than an .OR., and easy mistake. If so, the error might have been made by someone writing in English rather than a programmer. Who knows?

Or maybe some white-hat nerd inside PG&E thought NBC's violated the brillient purity of NEM, and built in a back door int NEM2 where higher NBC's could result in a lower net bill. Clever nerd, if true.

Could any other NEM 2.0 and EV2A non-CCA users share their recent true-up tables?

I think the cases I'd like to see are those where the table called True-Up Evaluation has the entry called Evaluation Result as "NBC TRUE-UP", like mine. Yours said "MINNIMUM TRUE-UP", which made complete sense. The circumstances in which the NBC true-up is done is what is in play here.

 

[swedge]

It just doesn't make any sense at all. The two biggest items that stand out to me are

• Distribution is negative (-$230.87), but transmission is positive ($138.06) and generation is positive ($247.08)
• The net generation is positive, but it was zero'ed out for the calculation and the net generation kWh is also positive

I can't wrap my head around how your distribution could be negative with the other two positive. Do you only draw from the grid during Off-Peak and maybe are using the Export Everything during Peak? Since EV2 Off-Peak distribution rate is only about 20% of the Part-Peak and Peak rates, I could maybe see that going negative. Then my next best guess is that a programmer made a mistake/simplification that made you a Net Generator and that zero'ed out the Generation Charge/Credit calculation.

Finally, I got a chance to look at this aspect. The explanation for this is in the unbundled EV2 rates, copy below. Specifically, the transmission rate is the same across peak, part-peak and off peak periods. However, Generation is 1.7 times higher in peak than off peak, and Distribution is up to 6 times higher during peak. So Exports have a bigger credit to Distribution during peak than the other two.

Every month, during peak periods, I was a net exporter, so that high Distribution rate resulted in a larger credit than the the off peak cost of imports, even though there are more imports total the exports. A small part of this was grid charging, but solar alone almost always was sufficient to do some exporting and no importing during peak, thanks to Export Everything.

I'm still trying to find some justification in the tariffs for basing my true-up on NBCs rather than the higher cumulative NEM charges (aka Cumulative Energy Charges). As far as I can see, the true-up is internally consistent and accurate, except for using what appears to be the wrong rule. I have looked at a few other's true-ups, but they all followed the rules as described in NEM-PS Annual True-Up Calculation [PG&E example]

Thanks again for looking into this little (i.e. only $67.43) mystery.

EV2 Unbundling:

 

[swedge]

I think I have found the mistake PG&E made on my June true-up. I suspect it was, to borrow from HAL 9000, a human error.

To sumerize, PG&E undrcharged me in my true-up, by using NBC’s rather than the higher Cumulative Energy Charges and Credits (CECCs, formerly called NEM charges) to calculate what I owed.

By a coincedentally, I recived another true-up one month later in July which is a whole other story. The one-month true up followed the same logic and used the same NBC true-up calculation, but his time it was correct - the NBCs were larger than the CECCs. But there was a difference in the bills. If anyone is interested, I can share the details. But in the June comparison of the various charges, they deducted the generation charges from the CECCs inappropratly, and in the July bill they were included correctly.

Was this a bug in the billing software, or was it a human error? The reasont I wanted to understand was so I could predict what would happen next year. Was this a one-off goof, or is there a loop-hole that I could try to exploit again. It is hard to imagine that some billing employee actually looked at and made a mistake in my billing, but in the absence of finding another similar case, I have to suspect the one-off human error explanation.

So, for now, I will assume that the higher of NBCs, MDCs or CECC’s will be the basis of my next true-up, and I will decide on how to adjust my PW settings accordinging.

If anyone has had an NBC true-up when their CECC’s were actually larger, please let us know.