NEM-PS Annual True-Up Calculation [PG&E example]

[YRide]

Has anyone that got PTO in 2023 ever seen the B&W Bill? Or is that not a thing anymore?

I got PTO in June 2023, and I still can’t get the B&W bill. I get the “new” Blue bill…which has the much nicer YTD charges for true-up (not a forecast), and better details of NEM chargers, MDC, NBC, etc.

However, it does NOT have the monthly generation/export cap table, which concerns me as I could in theory surpass that with GC+EE as well as PV export.

 

[miimura]

Has anyone that got PTO in 2023 ever seen the B&W Bill? Or is that not a thing anymore?

I got PTO in June 2023, and I still can’t get the B&W bill. I get the “new” Blue bill…which has the much nicer YTD charges for true-up (not a forecast), and better details of NEM chargers, MDC, NBC, etc.

However, it does NOT have the monthly generation/export cap table, which concerns me as I could in theory surpass that with GC+EE as well as PV export.

Call the solar department and tell them your concerns. Tell them that if they’re going to disallow credits, they have to show you the complete billing statement that could explain it.

I got PTO on 10/20/2023 for my new solar array that should push me from NEM 1 to NEM 2. I am still accumulating usage on my NEM 1 annual cycle that is due to true up in April. I am not calling because them doing nothing is in my favor. I fully expect them to reverse all the billing back to the PTO date, close out the old cycle on NEM1 and then recalculate all the usage since PTO in a new NEM 2 annual cycle.

I suppose you could look at your situation in the same way: they can’t disallow credits without showing their work. However, if you are going to change your behavior based on what the billing shows, then you could get messed up. I am not going to change anything no matter if they bill me on NEM1 or NEM2.

 

[SVDNN]

Has anyone that got PTO in 2023 ever seen the B&W Bill? Or is that not a thing anymore?

I got PTO in June 2023, and I still can’t get the B&W bill. I get the “new” Blue bill…which has the much nicer YTD charges for true-up (not a forecast), and better details of NEM chargers, MDC, NBC, etc.

However, it does NOT have the monthly generation/export cap table, which concerns me as I could in theory surpass that with GC+EE as well as PV export.

Have not been getting the B&W bill in mail, but you can still download from the PGE website. A little hidden...
Login and then where it has the Acct number at the banner, click on the down carrot next to the number and then click on "My account & services"...should be able to figure out from there.

 

[YRide]

Have not been getting the B&W bill in mail, but you can still download from the PGE website. A little hidden...
Login and then where it has the Acct number at the banner, click on the down carrot next to the number and then click on "My account & services"...should be able to figure out from there.

I’m aware of the hidden location. It’s not there. There is some thinking that actually going forward, there will be no more B&W bill, people will just be moved to the “new” Blue bill movinng forward.

When was your PTO date?

We have yet to see a person with PTO after May 2023 that has moved to NEM2PS and/or B&W bill (mailed or via PGE.com)

 

[hill Clinton]

Holy crap! I hope I don't have to wade through that gobbledegook when my National Grid True-Up comes due.

 

[tfan2018]

Just had my second true up with PG&E. I fumbled on managing my NBCs this year so I had to pay $8 extra. If I don't normally charge my cars during the daytime with excess solar NBCs would have been much much higher.

 

[holeydonut]

Just had my second true up with PG&E. I fumbled on managing my NBCs this year so I had to pay $8 extra. If I don't normally charge my cars during the daytime with excess solar NBCs would have been much much higher.

Actual picture of @tfan2018 fumbling his NBCs.

 

[tfan2018]

Would have been a lot more had I not switched to self powered a few months back.

 

[swedge]

Just had my second true up with PG&E. I fumbled on managing my NBCs this year so I had to pay $8 extra. If I don't normally charge my cars during the daytime with excess solar NBCs would have been much much higher.

Cool! Congratulations! That is only about 250kWh too many of NBCs, so well done. Are you a net exporter?

Would have been a lot more had I not switched to self powered a few months back.

That is interesting. Did you "export everything" for part of the year?

We are also on PG&E, 6kW solar, 1 pw, so similar situation. Our first NEM2 true-up was weird, based on NBCs while NEM charges were higher. I'm trying to get both NBCs and NEM charges lower this year, and wondering if PG&E will make the same true-up error...

We have been playing with car charging during the day, but often that is when we need the car, so it is tricky.

If you feel like sharing your numbers (NEM charges, NBCs and MDCs) and strategy to get there, that would be appreciated.

 

[tfan2018]

Cool! Congratulations! That is only about 250kWh too many of NBCs, so well done. Are you a net exporter?

That is interesting. Did you "export everything" for part of the year?

We are also on PG&E, 6kW solar, 1 pw, so similar situation. Our first NEM2 true-up was weird, based on NBCs while NEM charges were higher. I'm trying to get both NBCs and NEM charges lower this year, and wondering if PG&E will make the same true-up error...

We have been playing with car charging during the day, but often that is when we need the car, so it is tricky.

If you feel like sharing your numbers (NEM charges, NBCs and MDCs) and strategy to get there, that would be appreciated.

Yup, net exporter here. I did export everything from time to time to participate in grid-energy saving program. But for the most part, it's just letting solar charge up my powerwalls (I added a second one late last year) and exporting the excess back to the grid. Otherwise, I don't pull any power from the grid during peak and off peak (except in winter when solar prod is low and my batteries can't fully charge up and I avoid grid-charging due to NBCs).

My cumulative energy charges at true up was -$370.
Cumulative NBC was $145.

NBC is my main constraint--if I charge my cars overnight rather than during the daytime, my NBCs would be much much higher.

How does yours look?

 

[swedge]

Yup, net exporter here. I did export everything from time to time to participate in grid-energy saving program. But for the most part, it's just letting solar charge up my powerwalls (I added a second one late last year) and exporting the excess back to the grid. Otherwise, I don't pull any power from the grid during peak and off peak (except in winter when solar prod is low and my batteries can't fully charge up and I avoid grid-charging due to NBCs).

My cumulative energy charges at true up was -$370.
Cumulative NBC was $145.

NBC is my main constraint--if I charge my cars overnight rather than during the daytime, my NBCs would be much much higher.

How does yours look?

As a net exporter (or net generator as PG&E calls it) did you receive some credit for those surplus exports? Did your $8 true-up adjustment include a small surplus export credit?

I am a net importer, so things are different. My first full year NEM2 true up was last June:

Cumulative energy charges showed me owing $357,​

NBC's totaled $191.​

Minimum Monthly Charges already paid totaled $124.​

​

From this, we would expect I owed a true-up adjustment of $357 - $124 or $233. That is not what they charged me. Instead, they calculated based on the NBCs, so it was $191 - 124, only $67. This anomaly was discussed at length in another thread: PG&E NEM2PS True-Up Calculation? It remains a mystery, so I am waiting to see what they do this year.

Export Everything and Grid Charging (for cloudy days) are my normal settings, though this year I am trying to do as much car charging durning the day as I can to reduce NBCs.

I do wonder about the difference between your results and mine. Your solar is a bit bigger, but also I have tall trees to the west, so there is substantial shading and reduced solar production. Also, with just one PW, a fair amount or our export is during off-peak rate period, before 3 PM, so we get an NBC hit on those kWhs. A second PW would let me time shift much of that export to peak pricing, getting more credit.

(I do wish I had installed 2 PWs, but Export Everything was not an option back then. Now, investing $10k to save $68 a year (or whatever they decide to charge me this year) is tough to justify.)

Tesla App says my solar produced 7,187 kWh in calendar 23, 20 per day on average. The car charged 3,996kWh at home (doesn't include supercharging), around 11 per day. The net PG&E in that true-up was 2,759kWh, so the house uses roughly 5,950 or 16kWh per day. Is this profile similar to yours?

 

[tfan2018]

As a net exporter (or net generator as PG&E calls it) did you receive some credit for those surplus exports? Did your $8 true-up adjustment include a small surplus export credit?

I am a net importer, so things are different. My first full year NEM2 true up was last June:

Cumulative energy charges showed me owing $357,​

NBC's totaled $191.​

Minimum Monthly Charges already paid totaled $124.​

​

From this, we would expect I owed a true-up adjustment of $357 - $124 or $233. That is not what they charged me. Instead, they calculated based on the NBCs, so it was $191 - 124, only $67. This anomaly was discussed at length in another thread: PG&E NEM2PS True-Up Calculation? It remains a mystery, so I am waiting to see what they do this year.

Export Everything and Grid Charging (for cloudy days) are my normal settings, though this year I am trying to do as much car charging durning the day as I can to reduce NBCs.

I do wonder about the difference between your results and mine. Your solar is a bit bigger, but also I have tall trees to the west, so there is substantial shading and reduced solar production. Also, with just one PW, a fair amount or our export is during off-peak rate period, before 3 PM, so we get an NBC hit on those kWhs. A second PW would let me time shift much of that export to peak pricing, getting more credit.

(I do wish I had installed 2 PWs, but Export Everything was not an option back then. Now, investing $10k to save $68 a year (or whatever they decide to charge me this year) is tough to justify.)

Tesla App says my solar produced 7,187 kWh in calendar 23, 20 per day on average. The car charged 3,996kWh at home (doesn't include supercharging), around 11 per day. The net PG&E in that true-up was 2,759kWh, so the house uses roughly 5,950 or 16kWh per day. Is this profile similar to yours?

No mention of export surplus credits yet. Last year my system generated 9.3 MWh and I consumed 8.1 MWh (including car charging). I ended up adding a second powerwall, so I am considering running more appliances like my washer/dryer during part peak / peak to limit my NBCs. It’s good that you got the lower true up amount, the error worked in your favor

 

[swedge]

No mention of export surplus credits yet. Last year my system generated 9.3 MWh and I consumed 8.1 MWh (including car charging). I ended up adding a second powerwall, so I am considering running more appliances like my washer/dryer during part peak / peak to limit my NBCs. It’s good that you got the lower true up amount, the error worked in your favor

Your "Net Generation Credit" shows up on the first page of your black&white bill. Working backwards from your number and a guess of $0.05 credit per excess kWh, it may have been around $60, and it may have been subtracted from what you owed.

Our systems are very similar, so the comparison is helpful to me as I try to figure out how to minimize my upcoming true-up. The differences are significant, though. Your solar produced roughly 30% more than mine, probably due to afternoon shading on mine. My consumption was also ~20% higher than yours. Your two PW's also let you export more than my single one does when using Export Everything to take advantage of the higher rates after sundown.

Since you had a positive NEM credit (AKA Cumulative Energy Charges and Credits) which is forfeited at true-up, switching from Time Based to Self Powered makes sense. As does off-peak daytime car charging, washer dryer, dishwasher, etc, so those kWh are never imported, and hence not charged NBCs.

On the other hand, your monthly minimum (MDC) of around $125 per year is credited against the NBC's at true-up, and the MDC is also not refundable, so getting the total NBC's below $125 won't improve your true-up. Still, extra exports will be credited (at a low price) and and will improve your net, so those will also help.

Thank you for sharing. The rules are quite complicated, which make optimizing difficult.

 

[tfan2018]

Your "Net Generation Credit" shows up on the first page of your black&white bill. Working backwards from your number and a guess of $0.05 credit per excess kWh, it may have been around $60, and it may have been subtracted from what you owed.

Our systems are very similar, so the comparison is helpful to me as I try to figure out how to minimize my upcoming true-up. The differences are significant, though. Your solar produced roughly 30% more than mine, probably due to afternoon shading on mine. My consumption was also ~20% higher than yours. Your two PW's also let you export more than my single one does when using Export Everything to take advantage of the higher rates after sundown.

Since you had a positive NEM credit (AKA Cumulative Energy Charges and Credits) which is forfeited at true-up, switching from Time Based to Self Powered makes sense. As does off-peak daytime car charging, washer dryer, dishwasher, etc, so those kWh are never imported, and hence not charged NBCs.

On the other hand, your monthly minimum (MDC) of around $125 per year is credited against the NBC's at true-up, and the MDC is also not refundable, so getting the total NBC's below $125 won't improve your true-up. Still, extra exports will be credited (at a low price) and and will improve your net, so those will also help.

Thank you for sharing. The rules are quite complicated, which make optimizing difficult.

Are you in a community choice aggregration program? My 2nd true up will occur in April with San Jose Clean Energy, so that may be why PG&E B&W bill isn't indiciating any credits for excess energy generation. I have access to cheaper charging at work combined with limited time unlimited supercharging miles, so my home energy usage isn't as high as it should be if I had done all my charging at home. When that happens, my NBCs will definitely go up since Charging On Solar exclusively isn't feasible year round and now I have two EVs.

 

[swedge]

Are you in a community choice aggregration program? My 2nd true up will occur in April with San Jose Clean Energy, so that may be why PG&E B&W bill isn't indiciating any credits for excess energy generation. I have access to cheaper charging at work combined with limited time unlimited supercharging miles, so my home energy usage isn't as high as it should be if I had done all my charging at home. When that happens, my NBCs will definitely go up since Charging On Solar exclusively isn't feasible year round and now I have two EVs.

I am not on CCA, just pure PG&E. Another difference between our situations.

At the risk (certainty really) of over-explaining, here is why your case is very interesting to me:

We had solar prior to getting our Model Y, and under NEM1 our true-up was near zero. Ah, the days of E1 pricing when time of use and import vs export didn't matter. Then SGIP gave us a "free" PowerWall, still on NEM1, so life was good and simple and now reliable. Next came the car in Dec 2020, and as a nice surprise, we got a year of free supercharging! So every few days I'd drive down to the Coliseum charging station for free electrons. (The down sided was missing out on the joy of waking up every day with a full "tank".) Originally we thought we'd just pay for car charging in our PG&E bill, like we always paid for gas for cars, pay as you go. But perhaps adding some more solar would be cost effective, so I spent hours on excel figuring out how much solar to add. The answer was to add more than was allowed under NEM1 because the savings exceeded the NBCs, so we switched to NEM2. Sadly, limitations of roof space, shading, single PowerWall and capital cost required compromise. The plan was to charge the car at night, off-peak, and let the PW do it's thing to shift all our home use also to off peak. Simple, and decent ROI on the extra panels.

Then along came Grid Charging, Export Everything, and now Charge on Solar. Hello $avings, but goodby simplicity. Oh, and then PG&E not following their own tariff and-under charging us added extra uncertainty! Optimization has become a full time distraction. At this point I using Charge HQ to charge the car during daylight to minimize off-peak exports, and use a bit of python code to toggle Grid Charging on a schedule to prevent early PW charging while assuring 100% when the rates go up. To update my estimated of the eventual true-up, I'm logging each month's B&W bill with kWh import and export for each price period, using last year's monthly info to complete the estimate. Like I said, a full-time distraction.

Your situation, very similar to mine except for your extra PowerWall, is a case study on an option I am considering: adding a second PW, which would also allow a bit more solar. This would cost maybe 15k$, which is hard to justify to reduce my true-up by maybe $200/yr, but it might also buy back some simplicity. Besides, the future probably includes some heat pumps to replace "natural" gas appliances so the pay-back might make sense.... I can see yet another excel simulation in my future....

Thanks again for sharing your story. And congratulations on your $8 true-up! Well done!

 

[RKCRLR]

I'm a net generator (barely) and was using Time Based Control but because of the way TBC works it tends to generate NBCs. The main thing from keeping me switching to Self-Powered mode is there is no way to tell the app to optimize operation to avoid drawing power from the grid during peak hours. Tesla really needs a hybrid setting between Self-Powered and Time Based Control.

The Netzero app now allows some automation (great app!) and I have switched to Self-Powered mode. Normally my reserve is set at 50% in the winter. I have frequent power outages where I live and need a high reserve in the winter. However if I make it to 80% State of Charge by 3 pm I can usually make it through peak without hitting my reserve. I set up automations to increase my reserve and turn on grid charging in 3 increments (60%, 70%, and 80%) every 45 minutes starting at 12:45 pm. That way I have a backstop to make it through peak and so far it has been working good. Usually this only kicks in if it is cloudy or raining. There is a little bit lost due to the 10% round trip efficiency loss but the insurance is worth it to me.

 

[swedge]

I'm a net generator (barely) and was using Time Based Control but because of the way TBC works it tends to generate NBCs. The main thing from keeping me switching to Self-Powered mode is there is no way to tell the app to optimize operation to avoid drawing power from the grid during peak hours. Tesla really needs a hybrid setting between Self-Powered and Time Based Control.

The Netzero app now allows some automation (great app!) and I have switched to Self-Powered mode. Normally my reserve is set at 50% in the winter. I have frequent power outages where I live and need a high reserve in the winter. However if I make it to 80% State of Charge by 3 pm I can usually make it through peak without hitting my reserve. I set up automations to increase my reserve and turn on grid charging in 3 increments (60%, 70%, and 80%) every 45 minutes starting at 12:45 pm. That way I have a backstop to make it through peak and so far it has been working good. Usually this only kicks in if it is cloudy or raining. There is a little bit lost due to the 10% round trip efficiency loss but the insurance is worth it to me.

Thank you for the lead on Netzero app. Getting my python scrip working was mind bending for this old assembly language hacker. It was free, but keeping my Mac awake cuts a bit into the small savings in NBCs it achieves. Should I worry about how they afford to do a free app?

I've been manually switching between TBC and SP modes sometimes, so the Netzero automation of the mode changes may help me automate that, as well as let my Mac get some zero cost sleep.

I also want to think more about your strategy. PG&E's rates make optimization tricky, especially for those of us who end up with small true-ups. Net zero true up is even harder than net zero carbon! ;-)

 

[RKCRLR]

Thank you for the lead on Netzero app. Getting my python scrip working was mind bending for this old assembly language hacker. It was free, but keeping my Mac awake cuts a bit into the small savings in NBCs it achieves. Should I worry about how they afford to do a free app?

I've been manually switching between TBC and SP modes sometimes, so the Netzero automation of the mode changes may help me automate that, as well as let my Mac get some zero cost sleep.

I also want to think more about your strategy. PG&E's rates make optimization tricky, especially for those of us who end up with small true-ups. Net zero true up is even harder than net zero carbon! ;-)

The author of Netzero (@offandonagain) is active on the forum. I don't think you need to worry about his app. All he asks is that you provide a review of how you like his app.

Here is a link to a thread about his app:

Netzero App

Many you have been using the app already, but I figured a proper announcement is in order since a lot has changed since the previous app (pwmon.io): Netzero App is available for iOS and Android Netzero adds several features over the Tesla app: PVWatts estimates to diagnose issues: answer the...

teslamotorsclub.com

Now that automation is available to mere mortals I was thinking about starting a thread dedicated for the best strategy to minimize NBCs and PG&E charges for net generators but never got around to it.

 

[swedge]

The author of Netzero (@offandonagain) is active on the forum. I don't think you need to worry about his app. All he asks is that you provide a review of how you like his app.

Here is a link to a thread about his app:

Netzero App

Many you have been using the app already, but I figured a proper announcement is in order since a lot has changed since the previous app (pwmon.io): Netzero App is available for iOS and Android Netzero adds several features over the Tesla app: PVWatts estimates to diagnose issues: answer the...

teslamotorsclub.com

Now that automation is available to mere mortals I was thinking about starting a thread dedicated for the best strategy to minimize NBCs and PG&E charges for net generators but never got around to it.

If you have a system and strategy which works, I would suggest you do post it. As a net importer, I am still working to find a good solution, but insights from net exporters have proven helpful to me.

Optimizations depend on which utility, which rate plan, system size, battery count, house and car charging load, so perhaps a new thread on optimizations for PG&E would make sense.

 

[YRide]

The author of Netzero (@offandonagain) is active on the forum. I don't think you need to worry about his app. All he asks is that you provide a review of how you like his app.

Here is a link to a thread about his app:

Netzero App

Many you have been using the app already, but I figured a proper announcement is in order since a lot has changed since the previous app (pwmon.io): Netzero App is available for iOS and Android Netzero adds several features over the Tesla app: PVWatts estimates to diagnose issues: answer the...

teslamotorsclub.com

Now that automation is available to mere mortals I was thinking about starting a thread dedicated for the best strategy to minimize NBCs and PG&E charges for net generators but never got around to it.

I will have a good data set to work of after this June (1st PGE true up but I think my SJCE true up doesn’t actually happen for an entire additional year after that per their “10 bill/month policy”.

My NBC’s will dominate this year because of running TBC+GC+EE with 4 powerwalls. My NBC is ~= my YTD NEM balance today, but there are still 3mo to go. But I suspect in the months of April, May and June my YTD NEM will get closer to zero and my NBC’s will keep going up because of the GC.

So I probably need to need to get better at reducing the GC+EE to keep NBC’s minimized. It would be great if Tesla offered these smarts in their SW for tuning it with complex utility tariffs in mind.