Study on NEM 1.0 vs. NEM 2.0

[derrallg]

I was looking at this article on the need to compensate for the TOU rates and other requirements of NEM 2.0. The article is based on this study . Now I'm wondering if I need to bump up my percentage of usage that I'm trying to cover. I've been collecting bids at the 85% to 90% range and I wonder if that is enough. Even if I cover all my energy usage I'll still have it looks like a $120 NBC charge at my true up statement. The conclusion of the study is:
Screen Shot 2017-07-23 at 7.32.40 PM.png
After wanting to learn more about the NBC charges that will result no matter how much I'm putting back in the system, I found a good video on the subject at NorCalSolar organization

[Mike7381]

Correct me if I am wrong, I believe the NBC charge only applies on the energy that you pull from the grid? Another word is, your system generated less than you consume.

[cebury]

Correct me if I am wrong, I believe the NBC charge only applies on the energy that you pull from the grid? Another word is, your system generated less than you consume.

Correct, at this time the POCO is not aware of any energy you consume that is self generated. Therefore its calcd on the toal Imported energy.
There were crazy proposed feed in tariffs (not sure if any still exist is US) that proposed doing all export, all import so the poco could still charge you for everything you consumed and pay you separetly for what you generate.

[cebury]

I was looking at this article on the need to compensate for the TOU rates and other requirements of NEM 2.0. The article is based on this study . Now I'm wondering if I need to bump up my percentage of usage that I'm trying to cover. I've been collecting bids at the 85% to 90% range and I wonder if that is enough. Even if I cover all my energy usage I'll still have it looks like a $120 NBC charge at my true up statement. The conclusion of the study is:
Screen Shot 2017-07-23 at 7.32.40 PM.png
After wanting to learn more about the NBC charges that will result no matter how much I'm putting back in the system, I found a good video on the subject at NorCalSolar organization

Anyone who wants to make the PV sale can always explain that since the evil POCO is paying you less by 1)adding new charges like NBCs, 2) moving time windows, and 3) adjusting TOU rates around, the solution necessitates a larger system than before, to get your bill to X% range. That logic will ALWAYS demand more panels as the POCOs find ways to stop the bleeding from rooftop competition. If your point of view aligns with this logic, your decision is easy.

The article in greentech was pretty lacking in several spots (and i watched the video as well). The big takeaway from the article for me was: you have to do the difficult work of modeling your electric profile accurately to get payback time (using current and expected POCO rate structures) or to answer the question you are asking: how much kwh usage do i offset in order to offset 100% of bill (less minimum). There is no general answer and it all depends on your usage profile and PV installation (ignore the article's vague and useless statement of 89.5 nem1 vs 86% nem2). Its harder to calculate now than it was a year ago, but there are tools online to help you.

Either do the work and numbers correctly with your greenbutton data and find the sweet spot to maximize your dollars and minimize payback time. Alternatively, take the hands off much easier approach and risk it. If your reasonably sure you'll live there long enough for simple payback, can afford it, maybe you dont need to know the exact # panels needed today. I'd only expect rates to increase in CA with our energy policies. If you agree with the aforementioned logic anyway, offset 100% and throw in a few extra panels now since rates will likely rise for PV users anyway and your panels degrade by a .5% each year anyway.

If you are with PGE you can offset 110% of 12 months usage without any special preapproval. As long as your proposed systems CEC-AC rating (kw) mulitplied by 1664 is less than your 12 months kWh x 1.1, you are OK.

As always, get enough quotes from different vendors and dont do a lease.

[J.P.M.]

Correct me if I am wrong, I believe the NBC charge only applies on the energy that you pull from the grid? Another word is, your system generated less than you consume.

That is wrong, and another example of your confusion I wrote about in a different, recent post to another thread.

NBC's are that portion of the UDC rate charges that are not reimbursable under NEM for that portion of the electricity a system generates that gets sent back to the grid.

So, if for some period, say an hour, a system generates 5 kWh and you consume 2 kWh, you will feed the difference (5 kWh - 2 kWh = 3 kWh) to the grid. Also say that the POCO rate for power for that hour is $0.20/kWh, and the NBC's for that hour are a total of $0.02 per kWh. If NBC's did not exist, the 3 kWh you sent to the grid would result in a 3 X $0.20 = $0.60 credit against your bill. But, because NBC's do exist those 3 kWh you send to the grid generate a credit against your bill == ($0.20-$0.02) X (3kWh) = $0.54.

I read my meter every morning. Since my smart meter installation (09/20/2013), that meter says my system has sent 25,702 kWh to the grid. During that same time, SDG & E has sent me 17,522 kWh. If I was subject to NBC's, I'd have been credited the per kWh charge less whatever the NBC's charges were at that time. So, sticking with the above example, I'd have been credited ($0.20-$0.02 $/kWh) X (25,702 kWh) = $4,626.36 for electricity. If they had delivered that same amount of electricity to me under the same example as above, the charge would have been ($0.20) X ($0.20) = $ 5,140.40.

[J.P.M.]

I did not download the complete study because it requires I give information that I do not want to give.

However, I believe, after reading the article that the study is mostly B.S.

If what the article says is in the paper is being reported correctly and accurately, the paper is full if innuendo and twisted crap, a lot of which, if it is a statement of some truths, has those truths look to be twisted to make a trap for the solar ignorant.

Start with the idea that the article comes from Greentech Media - a greenwash rag with an agenda. Add that the source of the study is an outfit called Aurora. If that's the Aurora I'm thinking it is, their advert. statement says: "We are a diverse team based in Palo Alto CA, passionate about advancing the growth of solar energy". They peddle solar sizing software. I'll let those readers with a brian draw their own conclusions about the objectivity of both Greentech Media and Aurora.

I do not intend to chapter and verse the article. There is simply way too much that's B.S. in it. I'd be writing for the next several hours and still not get it all in.

I will say however, maybe as a way of speaking truth to B.S., that the best way to figure out how new rates in CA will affect you, is to run the bills you have now under the current (old ?) tariff you are (were) under, and then repeat the process using the new (likely)tariff you'll be under and compare the two.

I'm very well aware that's a real PITA, and not all that's required, but it's a start. The rest of the task is to SWAG what will happen in the future, not only from the standpoint of what directions the tariffs will take, but also from the standpoint of what users live's will look like over the next 5 - 10 - 20 years or so.

Example of one piece of the puzzle based on what I think I might know:

For my situation, using the current T.O.U. schedule for users with a PV, NEM 2.0 system, every STC kW of installed PV facing south at a 20 deg. tilt in zip 92026 will generate $506/yr. in revenue to offset a bill under the old T.O.U. schedule DR-SES. that amount under the new DR-SES tariff using the new times is $387/yr. in revenue to offset a bill That's a $119/$$506 = 23.5 % reduction in annual revenue, regardless of system size because there is no tier overlay for that schedule. That will, in a simple analysis, mean either the ROI will drop by 23.5 % or a system price has to drop by 23.5 $ to maintain the same cost effectiveness. It also means that increasing a system's size may well decrease the cost effectiveness, and, to put icing on the cake, increase, not decrease the impact of rate changes in the future. NBC's will reduce revenue under the old or new tariff about equally to the tune of somewhere between $0 and $30/yr. for this scenario under either the old or new schedule, depending on how much of a system's output is fed back to the grid.

Every situation will be different. You gotta' run the numbers.

Those who read the article and come away with the idea that how it describes rate change impact on them, and that what to do about such impact as describe in the article fits their situation are falling into the trap laid by those with skin in the game.

Bottom line: IMO, that article is very misleading in many ways too numerous the elaborate about here. I believe it's deceptive, in that it will give many readers who don't know any better, the idea that the way utilities are changing rates in CA, and for whatever reason(s), those changes will have little impact on the cost effectiveness of residential PV, and also that such impact can be offset simply by increasing proposed system sizes. The first implied assertion is, IMO, B.S. for most, if not all situations. The second assertion is utterly disingenuous and deceitful nonsense for most every situation, with reality being quite the opposite in fact, for more reasons than I've the time or inclination to delve into.

Caveat Praelector prior Caveat Emptor !

Take what you may want of the above. Scrap the rest

[derrallg]

I did not download the complete study because it requires I give information that I do not want to give.

However, I believe, after reading the article that the study is mostly B.S.

If what the article says is in the paper is being reported correctly and accurately, the paper is full if innuendo and twisted crap, a lot of which, if it is a statement of some truths, has those truths look to be twisted to make a trap for the solar ignorant.

Start with the idea that the article comes from Greentech Media - a greenwash rag with an agenda. Add that the source of the study is an outfit called Aurora. If that's the Aurora I'm thinking it is, their advert. statement says: "We are a diverse team based in Palo Alto CA, passionate about advancing the growth of solar energy". They peddle solar sizing software. I'll let those readers with a brian draw their own conclusions about the objectivity of both Greentech Media and Aurora.

I do not intend to chapter and verse the article. There is simply way too much that's B.S. in it. I'd be writing for the next several hours and still not get it all in.

I will say however, maybe as a way of speaking truth to B.S., that the best way to figure out how new rates in CA will affect you, is to run the bills you have now under the current (old ?) tariff you are (were) under, and then repeat the process using the new (likely)tariff you'll be under and compare the two.

I'm very well aware that's a real PITA, and not all that's required, but it's a start. The rest of the task is to SWAG what will happen in the future, not only from the standpoint of what directions the tariffs will take, but also from the standpoint of what users live's will look like over the next 5 - 10 - 20 years or so.

Example of one piece of the puzzle based on what I think I might know:

For my situation, using the current T.O.U. schedule for users with a PV, NEM 2.0 system, every STC kW of installed PV facing south at a 20 deg. tilt in zip 92026 will generate $506/yr. in revenue to offset a bill under the old T.O.U. schedule DR-SES. that amount under the new DR-SES tariff using the new times is $387/yr. in revenue to offset a bill That's a $119/$$506 = 23.5 % reduction in annual revenue, regardless of system size because there is no tier overlay for that schedule. That will, in a simple analysis, mean either the ROI will drop by 23.5 % or a system price has to drop by 23.5 $ to maintain the same cost effectiveness. It also means that increasing a system's size may well decrease the cost effectiveness, and, to put icing on the cake, increase, not decrease the impact of rate changes in the future. NBC's will reduce revenue under the old or new tariff about equally to the tune of somewhere between $0 and $30/yr. for this scenario under either the old or new schedule, depending on how much of a system's output is fed back to the grid.

Every situation will be different. You gotta' run the numbers.

Those who read the article and come away with the idea that how it describes rate change impact on them, and that what to do about such impact as describe in the article fits their situation are falling into the trap laid by those with skin in the game.

Bottom line: IMO, that article is very misleading in many ways too numerous the elaborate about here. I believe it's deceptive, in that it will give many readers who don't know any better, the idea that the way utilities are changing rates in CA, and for whatever reason(s), those changes will have little impact on the cost effectiveness of residential PV, and also that such impact can be offset simply by increasing proposed system sizes. The first implied assertion is, IMO, B.S. for most, if not all situations. The second assertion is utterly disingenuous and deceitful nonsense for most every situation, with reality being quite the opposite in fact, for more reasons than I've the time or inclination to delve into.

Caveat Praelector prior Caveat Emptor !

Take what you may want of the above. Scrap the rest

I didn't see anything notifying me that I couldn't upload it. So I'll do that. Here it is in case you want to see it more in depth.

[sensij]

Example of one piece of the puzzle based on what I think I might know:

For my situation, using the current T.O.U. schedule for users with a PV, NEM 2.0 system, every STC kW of installed PV facing south at a 20 deg. tilt will generate $506/yr. in revenue to offset a bill under the old T.O.U. schedule DR-SES, and $387/yr. in revenue to offset a bill under the new(proposed)same schedule DR-SES using the new T.O.U. times. That's a $119/$$506 = 23.5 % reduction in annual revenue, regardless of system size because there is no tier overlay for that schedule. That will, in a simple analysis, mean either the ROI will drop by 23.5 % or a system price has to drop by 23.5 $ to maintain the same cost effectiveness. It also means that increasing a system's size will decrease the cost effectiveness, and increase, not decrease the impact of rate changes in the future. NBC's will reduce either revenue about equally to the tune of somewhere between $0 and $30/yr. under either the old or new schedule, depending on how much of a system's output is fed back to the grid.

Every situation will be different. You gotta' run the numbers. Those who read the article and come away with the idea that how it describes rate change impact on them and that what to do about as describe in the article fits their situation are falling into the trap laid by those with skin in the game.

Just to clarify, the change in TOU that J.P.M. is describing is SDG&E specific, and is only related to NEM-ST (as SDG&E calls it) or NEM2 (as PG&E calls it) in that TOU becomes mandatory for those who missed NEM 1.0. Most of the ROI hit described here was already absorbed by PG&E customers over a year ago, when E-6 closed and the later peak hours of E-TOU-A became standard. For those PG&E customers who missed out on E-6, the difference between NEM and NEM2 is much smaller.

For SDG&E customers, the change in DR-SES hours described here will hurt NEM 1.0 and NEM-ST equally, it isn't a NEM-ST problem. NEM-ST complicates it by "forcing" customers to be on TOU, although that requirement was delayed until now and is therefore getting more discussion time even though NEM-ST has been out for a while. NEM 1.0 customers have the choice (for now) to stay on the tiered plan, but that decision has very customer-specific benefit... I just elected to move my first system onto the grandfathered DR-SES plan (for 5 years), because I think the savings over the tiered DR plan will be worth it, and it shouldn't give up the ability to switch back to tiered 5 years from now if that option is still available and desirable at that time.

[sensij]

That is wrong, and another example of your confusion I wrote about in a different, recent post to another thread.

NBC's are that portion of the UDC rate charges that are not reimbursable under NEM for that portion of the electricity a system generates that gets sent back to the grid.

So, if for some period, say an hour, a system generates 5 kWh and you consume 2 kWh, you will feed the difference (5 kWh - 2 kWh = 3 kWh) to the grid. Also say that the POCO rate for power for that hour is $0.20/kWh, and the NBC's for that hour are a total of $0.02 per kWh. If NBC's did not exist, the 3 kWh you sent to the grid would result in a 3 X $0.20 = $0.60 credit against your bill. But, because NBC's do exist those 3 kWh you send to the grid generate a credit against your bill == ($0.20-$0.02) X (3kWh) = $0.54.

This is not how NBC's are calculated on any bill that I've seen. On my first NEM-ST SDG&E bill, the NBC's were calculated only on TOU periods which showed net consumption for the month, and were completely unrelated to the generated energy in the net generation time periods, which received full dollar credit for those periods, as they had under the original NEM.

A simplified example, consistent with how my bill was calculated:

Energy costs $0.20 / kWh in a two period system, peak and off peak.
Of that 0.20, $0.02 / kWh is from NBC's, and $0.18 / kWh is all of the other rate, fee, and tax components.

If the system generates net 100 kWh in the peak period over the whole month, I'd show $20 in NEM credits.
If the system consumes a net 100 kWh in the off peak period over the month, I'd show $18 in NEM charges, and $2 in NBC's.

Because NEM credits can offset only NEM charges (not NBC's or the minimum daily charge), my bill for the month would be $2 (+$8, assuming $10 month minimum bill), with $2 of unused NEM credits carrying forward to the next month.

I'll receive another bill this week, and will be looking to see if the same calculation holds. Another SDG&E customer CharlieEscCA has an even more inscrutable calculation going on in his bills, since all of the TOU periods in his bill were net generation, but they found a way to asses NBC's on just a handful of kWh despite several hundred kWh of actual energy import at night or during other times the PV system was not meeting the full demand. The potential for a true-up correction of NBC's to occur at the end of the year also exists, but for now, I'm just working on what actually shows up in the bill each month.

There is no guarantee that PG&E calculates NBC costs the same way as SDG&E. I sort of recall it being discussed in another thread with actual bills, but I didn't pay much attention since it didn't apply to me at the time. Maybe cebury was paying attention, or can tell me if I'm just imagining this.

[J.P.M.]

This is not how NBC's are calculated on any bill that I've seen. On my first NEM-ST SDG&E bill, the NBC's were calculated only on TOU periods which showed net consumption for the month, and were completely unrelated to the generated energy in the net generation time periods, which received full dollar credit for those periods, as they had under the original NEM.

A simplified example, consistent with how my bill was calculated:

Energy costs $0.20 / kWh in a two period system, peak and off peak.
Of that 0.20, $0.02 / kWh is from NBC's, and $0.18 / kWh is all of the other rate, fee, and tax components.

If the system generates net 100 kWh in the peak period over the whole month, I'd show $20 in NEM credits.
If the system consumes a net 100 kWh in the off peak period over the month, I'd show $18 in NEM charges, and $2 in NBC's.

Because NEM credits can offset only NEM charges (not NBC's or the minimum daily charge), my bill for the month would be $2 (+$8, assuming $10 month minimum bill), with $2 of unused NEM credits carrying forward to the next month.

I'll receive another bill this week, and will be looking to see if the same calculation holds. Another SDG&E customer CharlieEscCA has an even more inscrutable calculation going on in his bills, since all of the TOU periods in his bill were net generation, but they found a way to asses NBC's on just a handful of kWh despite several hundred kWh of actual energy import at night or during other times the PV system was not meeting the full demand. The potential for a true-up correction of NBC's to occur at the end of the year also exists, but for now, I'm just working on what actually shows up in the bill each month.

There is no guarantee that PG&E calculates NBC costs the same way as SDG&E. I sort of recall it being discussed in another thread with actual bills, but I didn't pay much attention since it didn't apply to me at the time. Maybe cebury was paying attention, or can tell me if I'm just imagining this.

As I stated, every situation is different. You gotta' run the numbers. My example, as stated, and not trying to explain any possible error on my part, was for a specific place and tariff as a means of showing possible complexities and some possible useful comparison against how different tariffs in SDG & E territory, and other I.O.U. tariffs may react.

I'm aware of and as perplexed as you may be by Charlie's conundrum of how he wound up with a so farb incalculable NBC number, but reducing the credit received for less than all the power exported to the grid seems to fit the possibilities of net exports to the grid being subject to NBC's (by time period).

My statements are my best interpretation of the information supplied by the CPUC and SDG & E., including, for example,under schedule NEM-ST, C.P.U.C sheet number 28174-E, from special condition 1.f., nonbypassable charges: "These shall be based upon the kWh consumed in each metered interval net of exports, over the course of each monthly billing period.".

I have not seen a NEM-ST bill. No one I monitor is on T.O.U., at least not yet. I could be mistaken in my interpretation. But, and no insult intended, I'm not sure your interpretation is correct either, at least as I think I understand what you're writing.

I think we may be making progress on understanding W.T.F. is going on here, but we may have a ways to go yet.

[J.P.M.]

I didn't see anything notifying me that I couldn't upload it. So I'll do that. Here it is in case you want to see it more in depth.

I never wrote that I couldn't upload it. I wrote that to get it, I'd need to supply information, that I was (and that I remain), unwilling to supply.

[sensij]

I have not seen a NEM-ST bill. No one I monitor is on T.O.U., at least not yet. I could be mistaken in my interpretation. But, and no insult intended, I'm not sure your interpretation is correct either, at least as I think I understand what you're writing.

I think we may be making progress on understanding W.T.F. is going on here, but we may have a ways to go yet.

Here you go:
20170724120135.pdf

Next month, I'll be in the situation with NEM credit carry forward, although the basic shape will look the same (Peak is net generation, Super-Off peak is net consumption, and Off-peak something in between.

In this bill, the NEM Credits (Shown as "Applied credits", since none are carried forward) look like the following. -93 kWh was the net for the month in the peak period.

UDC contribution = -93 kWh * 0.14184 = -13.19
EEEC contribution = -93 kWh * 0.35243 = -32.78
DWR-BC contribution = -93 kWh * .00549 = -0.51
State surcharge tax contribution = -93 kWh * 0.00029 = -0.03
State regulatory fee contribution = -93 kWh * 0.00043 = -0.04
San Diego Franchise fee contribution = 0.0578 * (UDC contribution + EEEC contribution) = -2.66
Others Franchise fee contribution = 0.0688 * (DWR-BC contribution) = -0.04

The sum of those numbers adds up to the 49.25 credit shown on page 4.

The NEM charges, on the other hand, are calculated accounting for NBC's. Off-peak + Super-off peak net consumption = (124 + 328) = 452 kWh

UDC contribution (subtracting NBC's) = 452 kWh * (0.14184 - 0.01191) = 58.73
EEEC contribution = (124 kWh * 0.09604) + (328 kWh * 0.04651) = 27.16
State surcharge tax contribution = 452 kWh * 0.00029 = 0.13
State regulatory fee contribution = 452 kWh * 0.00043 = 0.19
San Diego Franchise fee contribution = 0.0578 * (UDC contribution + NBC contribution + EEEC contribution) = 5.28
Others Franchise fee contribution = 0.0688 * (DWR-BC contribution) = 0.17

The sum of these numbers matches the 91.67 shown under NEM charges on page 4.

NEM Charges can be offset by NEM credits, which is valid since none of the non-bypassable charges were included in the offsettable NEM charge calculation. The NEM balance after the credits are netted against the charges is 42.42, which is greater than (0.329 * 32), so the minimum charge won't apply at this time. However, that 42.42 remains to be carried forward to next month, when I will have sufficient NEM credits to cover it, and also roll credits ahead to August. On my next statement, a minimum charge will apply, but the true whole minimum charge total won't be resolved until true-up.


That leaves the non-bypassable charges.
DWR-BC contribution = 452 kWh * .00549 = 2.48
Other NBC contribution = 452 kWh * 0.01191 = 5.38

Total NBC's = 7.86

This number is not shown directly, but implicitly agrees with the (192.14) line shown in "Additional charges/Payments" on page 4.
-200 EV credit + 7.86 NBC charge = -192.14

The combined total of all these numbers:
42.42 - 192.14 = -149.72, which matches the statement balance on pages 1 and 4.




Unfortunately for the OP, this is all SDG&E specific, and I have no idea how much of this is applicable to PG&E.

[J.P.M.]

Sensij: Maybe it's just the Luddite in me, but the .pdf reference in your most recent post simply led me back to Solar Panel Talk., so no bill to compare to the text.

Also, snooping around some more, the method I'm using for DR-SES, pre and post old/new times is the same method as CALSEIA suggests. I'm pretty sure it'll flush out what happens for less than 100 % offset systems at trueup, but like I said, I could be wrong as happens on a fairly and irritatingly regular basis.

Still, everything else I've read (and that's not to imply I believe everything, or even much of what I read), has consistently said that while NBC's are charged on everything consumed, the per kWh NEM credit for what's exported to the grid for any time period (15 minutes) is reduced by NBC's.

[derrallg]

I never wrote that I couldn't upload it. I wrote that to get it, I'd need to supply information, that I was (and that I remain), unwilling to supply.

Yes, I understood. You didn't want to provide personal information, and I already had. I thought there might be interest in seeing the full report. It provides a level of details that is missing from the article and gives a complete picture of how the statistical research was done and how the conclusions were reached.

[sensij]

Sensij: Maybe it's just the Luddite in me, but the .pdf reference in your most recent post simply led me back to Solar Panel Talk., so no bill to compare to the text.

Also, snooping around some more, the method I'm using for DR-SES, pre and post old/new times is the same method as CALSEIA suggests. I'm pretty sure it'll flush out what happens for less than 100 % offset systems at trueup, but like I said, I could be wrong as happens on a fairly and irritatingly regular basis.

Still, everything else I've read (and that's not to imply I believe everything, or even much of what I read), has consistently said that while NBC's are charged on everything consumed, the per kWh NEM credit for what's exported to the grid for any time period (15 minutes) is reduced by NBC's.

Did you try clicking on the file? I uploaded the pdf to solarpaneltalk's server, so it ought to point back to them, but will download a pdf however your browser handles that (it works correctly when i click on it). Here is a dropbox link, if that helps:

https://www.dropbox.com/s/1cljnr72es...20135.pdf?dl=0

I understand where you are coming from, everything I read and understood suggested an implementation like what you've written here would be correct. I've only shifted my stance since I've gotten my bill and worked through the numbers first hand.

Further supporting the implementation I've described in this thread, is no evidence that SDG&E is looking at the net of each 15 min period individually. For example, over the billing period that I've shared here, I can download the 15 min data from their site and re-create the 359 kWh net for the month, as well as the net totals for each time period. If I drill into the 15 min data though, I see the following:

Peak: -93 net kWh, 72 kWh imported and 165 kWh exported
Off-peak: 124 net kWh, 219 kWh import and 95 kWh exported
Super off peak: 328 kWh, all imported.

There is *nothing* in the bill that suggests NBC's are being applied to the 15 min export numbers, only the monthly net, as described above.