Study on NEM 1.0 vs. NEM 2.0

[J.P.M.]

Looks like I have to contact SDGE. My data is messed up because of a meter swap. The data I can export stops at the meter swap that was required because the prior meter would not take the NEM reprogramming.

sdge1.JPG

I can see data beyond 4/25 in the charts -- this is how I pull daily data into my spreadsheet I maintain.

The "Green Button" usually doesn't work for me. I just used the button next to the green button and it got me data for the dates I plugged in, 07/01/2017 to 07/28/2017,and it worked as of about 5 minutes ago.

Edit: I think our posts crossed on the wires. Yea, I bet you will need to contact them for info on dates prior to meter swap. I tried to get that same info from them but the old mechanical meter that got swapped out obviously had no hourly data history as it was read by a good eyeball 1X/billing period.

[CharlieEscCA]

Edit: I think our posts crossed on the wires. Yea, I bet you will need to contact them for info on dates prior to meter swap. I tried to get that same info from them but the old mechanical meter that got swapped out obviously had no hourly data history as it was read by a good eyeball 1X/billing period.

Yeah, my fault. I edited my post after I figured out the download spreadsheet feature button location.

My issue is that the only data I can download (and this is the data with the 15 minute breakdown) is the data up to 4/25/2017. There is no data after 4/25/2017.

[sensij]

Even when the meter isn't physically changed, just reprogramming between NEM and normal metering is enough to break the data collection. Looks like they messed yours up, hopefully they can get the right connection back in place soon.

Fwiw, I emailed them for more detail on how the 3 kWh is determined. I'm not optimistic I'll get a good response, and even if I get one, I'm even less optimistic that this is really how NBC surcharges will be calculated in the long run... But, we will see. I have a few more ideas to try out in the spreadsheet later that should make more logical sense, hope to find one that returns 3 kWh.

[J.P.M.]

Even when the meter isn't physically changed, just reprogramming between NEM and normal metering is enough to break the data collection. Looks like they messed yours up, hopefully they can get the right connection back in place soon.

Fwiw, I emailed them for more detail on how the 3 kWh is determined. I'm not optimistic I'll get a good response, and even if I get one, I'm even less optimistic that this is really how NBC surcharges will be calculated in the long run... But, we will see. I have a few more ideas to try out in the spreadsheet later that should make more logical sense, hope to find one that returns 3 kWh.

One other blinding flash of the obvious (DUH !?!?) that came to me this A.M. as I was doing my 1X/day meter reading was that if NBC's are indeed charged on everything delivered from the POCO - regardless of how much a system generates or what's done with that generation, be it used behind the meter or sent back to the POCO - I record how many kWh have been received from the POCO each day as well as how much I send back to the grid, and the meter reading. I'm still not sure (and from the looks of things, SDG & E may not be too sure or at least forthcoming) how that information may be useful or not. But, since 07/01/2017 through 0540 this A.M today, SDG & E has delivered 611 kWh to my meter. That may be all the information necessary to calculate NBC for a billing period. Maybe not. Anyone else have similar info for their meter ?

[CharlieEscCA]

One other blinding flash of the obvious (DUH !?!?) that came to me this A.M. as I was doing my 1X/day meter reading was that if NBC's are indeed charged on everything delivered from the POCO - regardless of how much a system generates or what's done with that generation, be it used behind the meter or sent back to the POCO - I record how many kWh have been received from the POCO each day as well as how much I send back to the grid, and the meter reading. I'm still not sure (and from the looks of things, SDG & E may not be too sure or at least forthcoming) how that information may be useful or not. But, since 07/01/2017 through 0540 this A.M today, SDG & E has delivered 611 kWh to my meter. That may be all the information necessary to calculate NBC for a billing period. Maybe not. Anyone else have similar info for their meter ?

The PUC document that was linked somewhere stated that (per my understanding of what I read) that the meters have two separate channels, one that reads the power to the grid, and the other reads the power from the grid.

What the utilities wanted was that NBC are charged on every kWh from the grid.

What the PUC has approved, until they review it, is that the NBC applies to the summed NBC or various periods of net from the grid.

One can apply all kinds of "periods". It could be 15 minutes. It could be one hour (this is what we think it's supposed to be). It could be one day. It could be the entire billing period.

However, the only conclusion that I can draw from three data points of sensj and myself, namely 3 kWh, 6 kWh, and 10 kWh of NBC billed kWh for three separate bills is that SDGE has a billing software error. I suspect they may someday correct it. In the big picture of things, the possible $ that could be billed later are small enough that I'm not going to be too concerned. Especially as I look at $$$$$$$$$$$$$$ for my new home project -- oh what have I done???

[sensij]

One other blinding flash of the obvious (DUH !?!?) that came to me this A.M. as I was doing my 1X/day meter reading was that if NBC's are indeed charged on everything delivered from the POCO - regardless of how much a system generates or what's done with that generation... Anyone else have similar info for their meter ?

See my post at 3:04 pm yesterday. Using the most granular 15 min increment, my imports totaled 415 kWh in my last billing period.

[J.P.M.]

The PUC document that was linked somewhere stated that (per my understanding of what I read) that the meters have two separate channels, one that reads the power to the grid, and the other reads the power from the grid.

What the utilities wanted was that NBC are charged on every kWh from the grid.

What the PUC has approved, until they review it, is that the NBC applies to the summed NBC or various periods of net from the grid.

One can apply all kinds of "periods". It could be 15 minutes. It could be one hour (this is what we think it's supposed to be). It could be one day. It could be the entire billing period.

However, the only conclusion that I can draw from three data points of sensj and myself, namely 3 kWh, 6 kWh, and 10 kWh of NBC billed kWh for three separate bills is that SDGE has a billing software error. I suspect they may someday correct it. In the big picture of things, the possible $ that could be billed later are small enough that I'm not going to be too concerned. Especially as I look at $$$$$$$$$$$$$$ for my new home project -- oh what have I done???

Yea, it's my understanding at this time, that the NBC's are supposedly calculated per interval period, 15 minutes, 1 hr., whatever, and summed for all hours in a billing period. I tend toward agreeing with your thoughts on software errors, and that's were I'd put my money if I was subject to NBC. However, while I think such errors are certainly possible, and perhaps even likely, I also think it's possible that the differences seen may have other, or additional, causes. For example, the after market software (or hardware) that's being used can also have glitches or calibration errors. Given the relatively small differences observed, if things disagree with what the POCO meter thinks by a % or so, that would account for a good portion or all of a, say, 5 kWh/billing period difference over what the customer's monitoring equipment shows. One other thing I thought about was that perhaps SDG & E makes some type of adjustment in the quantity of kWh subject to NBC for some or all of the gross overgeneration such as such overgeneration may occur in a billing cycle.

Not trying to argue - just get to the bottom of W.T.F. is going on.

[sensij]

The only data I've seen discussed comes directly from the power company's meter, so I would strike equipment error from the list of possibilities.

[sensij]

In this bill, the NEM Credits (Shown as "Applied credits", since none are carried forward) look like the following. -1091 kWh was the net for the month in the peak and off peak periods.

UDC contribution = -1091 kWh * 0.14184 = -154.75
EEEC contribution = -1091 kWh * 0.35243 = -292.97
DWR-BC contribution = -1091 kWh * .00549 = -5.99
State surcharge tax contribution = -1091 kWh * 0.00029 = -0.32
State regulatory fee contribution = -1091 kWh * 0.00043 = -0.47
San Diego Franchise fee contribution = 0.0578 * (UDC contribution + EEEC contribution) = -25.88
Others Franchise fee contribution = 0.0688 * (DWR-BC contribution) = -.41

The sum of those numbers adds up to the (428.02 + 52.77) remaining + applied credits shown on page 4.

The NEM charges, on the other hand, are calculated accounting for NBC's. Super-off peak consumption =280 kWh

UDC contribution (subtracting NBC's) = 280 kWh * (0.14184 - 0.01191) = 36.38
EEEC contribution = 280 kWh * 0.04651 = 13.02
State surcharge tax contribution = 280 kWh * 0.00029 = 0.08
State regulatory fee contribution = 280 kWh * 0.00043 = 0.12
San Diego Franchise fee contribution = 0.0578 * (UDC contribution + NBC contribution + EEEC contribution) = 3.05
Others Franchise fee contribution = 0.0688 * (DWR-BC contribution) = .11

The sum of these numbers matches the 52.77 shown under NEM charges on page 4.

That leaves the non-bypassable charges.
DWR-BC contribution = 280 kWh * .00549 = 1.54
Other NBC contribution = 280 kWh * 0.01191 = 3.33

Total NBC's = 4.87

This number is not shown directly, but implicitly agrees with the "Additional charges/Payments" on page 4.

Additional charges and payments last month = (192.14)
Additional charges and payments this month = (187.27)
Dfference = 4.87

But wait, there are an additional 3 kWh tacked on for reasons unknown (one speculation a few posts ago), which adds 0.06 of NBC charges to real cash ledger.
This is also shown in the breakdown of line items on page 3. For example, Public Purpose Programs has a charge of 3.01. At 0.01063 / kWh, it agrees with 283 kWh contrubuting to that particular NBC.

There is more insight to be gleaned on how the minimum bill will be calculated for NEM-ST, I'll show that break down later.

[With respect to the massive over-production, I just added a 2nd EV that will be running 20k mi / annually at ~250 Wh / mi, so I expect to see another 400 kWh of consumption monthly. If you aren't familiar with the unlimited miles lease available for the Hyundai Ioniq, that might be worth its own thread]


Bill images below:

july page 1.JPG

july page 2.JPG

july page 3.JPG
july page 4.JPG

[CharlieEscCA]

...

Total NBC's = 4.87

This number is not shown directly, but implicitly agrees with the "Additional charges/Payments" on page 4.

Additional charges and payments last month = (192.14)
Additional charges and payments this month = (187.27)
Dfference = 4.87

...

Your bill is $9.87 plus taxes on electric used (electric was actually credited back from your balance).

And $9.87 comes from $0.329 minimum per day x 30 days.

So not only is the NBC kWh off from what we expect, the NBC is being absorbed into the minimum monthly bill.

Enjoy

[sensij]

Your bill is $9.87 plus taxes on electric used (electric was actually credited back from your balance).

And $9.87 comes from $0.329 minimum per day x 30 days.

So not only is the NBC kWh off from what we expect, the NBC is being absorbed into the minimum monthly bill.

Enjoy

They make it look that way, don't they. The problem is that the actual account balance increased by $13.23. Under NEM 1.0, the account balance would only have increased by $9.87. I have actual NEM 1.0 bills from my older system, on this same rate plan, that show that.

The actual statement shows the minimum bill adjustment on this bill was $8.30. $8.30 + $4.87 + $0.06 = $13.23. The 4.87 and the 0.06 are NBC's, so the trick is to figure out how the 8.30 was determined. More on that later.

[J.P.M.]

In this bill, the NEM Credits (Shown as "Applied credits", since none are carried forward) look like the following. -1091 kWh was the net for the month in the peak and off peak periods.

UDC contribution = -1091 kWh * 0.14184 = -154.75
EEEC contribution = -1091 kWh * 0.35243 = -292.97
DWR-BC contribution = -1091 kWh * .00549 = -5.99
State surcharge tax contribution = -1091 kWh * 0.00029 = -0.32
State regulatory fee contribution = -1091 kWh * 0.00043 = -0.47
San Diego Franchise fee contribution = 0.0578 * (UDC contribution + EEEC contribution) = -25.88
Others Franchise fee contribution = 0.0688 * (DWR-BC contribution) = -.41

The sum of those numbers adds up to the (428.02 + 52.77) remaining + applied credits shown on page 4.

The NEM charges, on the other hand, are calculated accounting for NBC's. Super-off peak consumption =280 kWh

UDC contribution (subtracting NBC's) = 280 kWh * (0.14184 - 0.01191) = 36.38
EEEC contribution = 280 kWh * 0.04651 = 13.02
State surcharge tax contribution = 280 kWh * 0.00029 = 0.08
State regulatory fee contribution = 280 kWh * 0.00043 = 0.12
San Diego Franchise fee contribution = 0.0578 * (UDC contribution + NBC contribution + EEEC contribution) = 3.05
Others Franchise fee contribution = 0.0688 * (DWR-BC contribution) = .11

The sum of these numbers matches the 52.77 shown under NEM charges on page 4.

That leaves the non-bypassable charges.
DWR-BC contribution = 280 kWh * .00549 = 1.54
Other NBC contribution = 280 kWh * 0.01191 = 3.33

Total NBC's = 4.87

This number is not shown directly, but implicitly agrees with the "Additional charges/Payments" on page 4.

Additional charges and payments last month = (192.14)
Additional charges and payments this month = (187.27)
Dfference = 4.87

But wait, there are an additional 3 kWh tacked on for reasons unknown (one speculation a few posts ago), which adds 0.06 of NBC charges to real cash ledger.
This is also shown in the breakdown of line items on page 3. For example, Public Purpose Programs has a charge of 3.01. At 0.01063 / kWh, it agrees with 283 kWh contrubuting to that particular NBC.

There is more insight to be gleaned on how the minimum bill will be calculated for NEM-ST, I'll show that break down later.

[With respect to the massive over-production, I just added a 2nd EV that will be running 20k mi / annually at ~250 Wh / mi, so I expect to see another 400 kWh of consumption monthly. If you aren't familiar with the unlimited miles lease available for the Hyundai Ioniq, that might be worth its own thread]


Bill images below:

july page 1.JPG

july page 2.JPG

july page 3.JPG
july page 4.JPG

Thank you. Clears up a lot of the accounting/B.S. That 3 kWh is still a mystery, but seems what you found rooting around in your bill makes sense, especially where it looks like the NBC might show up.

[CharlieEscCA]

They make it look that way, don't they. The problem is that the actual account balance increased by $13.23. Under NEM 1.0, the account balance would only have increased by $9.87. I have actual NEM 1.0 bills from my older system, on this same rate plan, that show that.

The actual statement shows the minimum bill adjustment on this bill was $8.30. $8.30 + $4.87 + $0.06 = $13.23. The 4.87 and the 0.06 are NBC's, so the trick is to figure out how the 8.30 was determined. More on that later.

We are just going to have to disagree

My read is the $13.23 account balance is the $9.87 plus $3.36 taxes shown on page 3 of 5. And the $3.36 comes franchise fees and taxes that are charged on the electrical use (the kWh delivered off peak) -- the $ for the electrical use get taken out by your applied credits as shown on page 4 in the net energy metering summary table.

So, in summary, I still contend that there were still yet to be understood very low NBC kWh, and the NBC $ (small that they were) were absorbed into the minimum daily charges, i.e. you actually paid no NBC $.

[sensij]

We are just going to have to disagree

My read is the $13.23 account balance is the $9.87 plus $3.36 taxes shown on page 3 of 5. And the $3.36 comes franchise fees and taxes that are charged on the electrical use (the kWh delivered off peak) -- the $ for the electrical use get taken out by your applied credits as shown on page 4 in the net energy metering summary table.

So, in summary, I still contend that there were still yet to be understood very low NBC kWh, and the NBC $ (small that they were) were absorbed into the minimum daily charges, i.e. you actually paid no NBC $.

I understand what you are reading, but for purposes of this thread, in particular, we want to understand NEM 1.0 vs NEM 2.0. Below are a couple pages from a NEM 1.0 bill on the same billing plan, with a similar consumption profile (net generator during peak, net consumer during super-off peak). There is a clear difference, looking at just the line items that you are focused on.

NEM 1.0 (29 day month)
Total electric charges = 6.05
Taxes and Fees = 3.49
Total electric service = 9.54

NEM-ST (30 day month)
Total electric charges = 9.87
Taxes and Fees = 3.36
Total electric service = 13.23

One possible explanation is that under NEM 1.0, the amount of the taxes and fees are included in the allowed "Applied generation credit", so only the minimum bill is left on the bottom line, while in NEM-ST, the taxes and fees are excluded from some calculations, so the total becomes the minimum bill + taxes and fees. I'm not sure yet that is the *right * explanation, since it wasn't on my radar that tax and fee handling was changing in NEM-ST, and I think there might still be an explanation that relies on NBC charges.

Your explanation also doesn't explain how the "NEM charges" or "applied generation credit" are calculated under either NEM 1.0 or NEM-ST, which are important numbers to understand when looking at how credits are calculated and consumed, determining what carries over from one month to the next. Under NEM-ST, the only way I can get this value to match what is shown in the Net Metering Summary table is by accounting separately for NBC's, as described above, while in NEM 1.0, I use the same calculations, but don't do anything special for NBC's. Hopefully you can see that based on the values shown in these bills, there is a different calculation at work between them.

NEM 1-1.JPG
NEM1-2.JPG

[CharlieEscCA]

...

NEM 1.0 (29 day month)
Total electric charges = 6.05
Taxes and Fees = 3.49
Total electric service = 9.54

NEM-ST (30 day month)
Total electric charges = 9.87
Taxes and Fees = 3.36
Total electric service = 13.23

...

We are both speculating (or at least I am )

It looks like NEM 1.0 taxes and fees get absorbed into minimum charge. Minimum charge is $0.329 x 29 days = $9.54

And in NEM 2.0, it's minimum charge + taxes and fees.

Who knows. Part of me is who cares, but I think we are both similar in we would like to know exactly how the bill is calculated and be able to get to the same exact amount. Instead, we are left trying to figure out how it got to that amount.