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Does anyone know how net metering with duke energy works?

BrettS

Active Member
Mar 28, 2017
2,129
2,540
Orlando, FL
So I just got my first power bill since I officially got PTO.

It shows that I used X amount of power from the grid and sent Y amount of power back to the grid. I used about 200kW more than I produced, so they charged me for the connection fee plus the 200kW that I used, which makes sense.

But I’m trying to figure out how it works if I produce more than I use, which will likely happen in the spring and summer. I called and spoke with someone at Duke and she said that any excess production will be carried forward and can be used in months where I use more than I produce, which also makes sense.

Then she said that once a year on the anniversary of my PTO date they will true up and cut a check for any excess production (at the wholesale rate).

However, this seems like it could be a problem for me, because my PTO date was 9/16. So the way I see it, from this point through the winter I will use more than I produce and need to pay for that excess power. But then in the spring and summer I will likely produce more than I use and those credits will build up. However, instead of allowing me to carry those credits forward to the next fall and winter they will 0 them out in September and cut me a check at the wholesale rate.

Is it possible that I (or the rep that explained this to me) is misunderstanding exactly how this works?
 

BrettS

Active Member
Mar 28, 2017
2,129
2,540
Orlando, FL
So just to follow up on this, I called Duke back and asked for them to clarify my understanding of how this worked. She said that what the previous rep had explained was basically correct, however, the true up doesn’t happen on the anniversary of the PTO, instead it is the same for everyone and it is actually based on the calendar year.

She said that after the last bill in December they will pay out any remaining credits at the wholesale rate and then it starts again at 0 in January.

This definitely seems better than having the true up happen in September, but it’s still not great. It seems like Feb or Mar would be a much better time for this, since Jan and Feb will likely also be low production months.

In my case I’m not entirely certain it’s going to matter too much to me. Since I think my system will only produce around 80% of my annual power usage, it’s pretty unlikely that I will have any credit at the end of December anyway. However, for someone who sized their system to meet 100% of their annual power demand I can see that this would come as a bit of a shock as they will almost certainly have a credit that gets zeroed out in December and then wind up buying power in Jan and Feb.
 
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jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
10,407
11,750
Riverside Co. CA
I am not on duke energy, but how you describe it is how it works for me on SCE. For the exact reason you describe, SCE allows you to change your "true up" date once (and I believe only once). Because my PTO date was in march (of 2016 for solar), I did not need to change my true up date since I start off my true up period producing more than I use.

Check with Duke to see if they have a provision to reset your true up date once, and consider changing it to February or March. That would make THIS true up period have a cost to you (since you would use more than you produce, then the true up would happen in Feb / March), but every year going forward, you would start off with the period generating credits that you would then pull from in the colder months.

EDIT.. your second post was not there when I posted this. Sounds like you dont have the option to reset it once like we do on SCE.
 

BrettS

Active Member
Mar 28, 2017
2,129
2,540
Orlando, FL
The second rep (who seemed to be more knowledgeable than the first one) mentioned that the true up period was fixed for all Duke customers in Florida and cannot be changed.

I think part of the issue is that I was under the impression that I wouldn’t actually be paying for the power I used as I used it. I was thinking that they would record how much power I used during the year and record how much power I produced during the year. Then once a year they would compare the amount of power I used to the amount of power I produced and either send me a bill for excess power use, or send me a check for excess production. If that was how it was done then it wouldn’t really matter when true up happened, however, it also has the potential for someone to wind up with a really big bill if their solar system doesn’t come close to their annual production amount.

Instead, though, I need to pay for excess power use when I use it, so no matter what there is no way to have credits for excess production apply to my Jan and Feb usage because that will already have been paid for in Jan and Feb.

I guess it’s possible that even this second rep is misunderstanding how things work. I guess I’ll see what happens at the end of the year. This year I’m certainly not going to have any credits at the end of December, so it’s really not going to matter until next year anyway.
 

BrettS

Active Member
Mar 28, 2017
2,129
2,540
Orlando, FL
And one more follow up. I found this on the energysage website here: 2020 Duke Energy Net Metering Rates | EnergySage

Florida
Any excess energy generation at the end of the billing month is credited to the customer's energy consumption for the next billing cycle. At the end of each calendar year, Duke Energy credits the customer for any unused net metering credits at an annual rate based on the COG-1 tariff.

So that certainly seems like the second agent was correct. I searched for a whole to find out exactly how much power was worth at the COG-1 tariff, but I was unable to find anything. I’m sure it’s not much though.
 

wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
This is similar to what PEPCO does, except that ours is fixed to the end of our billing period in April, whenever that is. I had expected to pay as I went, so that part doesn't concern me. However, similar to you, I am not entirely clear what happens if I am net user of power for they year (which is expected since my solar will be around 80%-85% of my power use) but my final bill before the "true-up" is negative. According to my billing data from PEPCO and estimated solar from PVWatts, the three calendar months I should be a net generator are March, April, May, and June (with over half in April.) So it would really suck if like a third of my excess generation was paid out at wholesale rates rather than carried forward to the next year, since I would definitely use the credits.

I am hoping that it remains as a credit since I am a net user for the year, but I am not entirely clear. If not, I will have to see if I can change my bill end date from the 15th to the 1st if PEPCO lets you pick.
 

GaitherBill

Member
Jun 10, 2020
98
60
Maryland/DMV
This is similar to what PEPCO does, except that ours is fixed to the end of our billing period in April, whenever that is. I had expected to pay as I went, so that part doesn't concern me. However, similar to you, I am not entirely clear what happens if I am net user of power for they year (which is expected since my solar will be around 80%-85% of my power use) but my final bill before the "true-up" is negative. According to my billing data from PEPCO and estimated solar from PVWatts, the three calendar months I should be a net generator are March, April, May, and June (with over half in April.) So it would really suck if like a third of my excess generation was paid out at wholesale rates rather than carried forward to the next year, since I would definitely use the credits.

I am hoping that it remains as a credit since I am a net user for the year, but I am not entirely clear. If not, I will have to see if I can change my bill end date from the 15th to the 1st if PEPCO lets you pick.


My understanding is that here in Maryland they cut you a check in April if you've generated more than used.

And it all resets.

Which is a shame, but it's designed to "protect consumers".
 

wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
My understanding is that here in Maryland they cut you a check in April if you've generated more than used.

And it all resets.

Which is a shame, but it's designed to "protect consumers".
That is a bummer, if that payout is at the wholesale rate. To me, what they should do (PEPCO, Potomac Edison, Duke, or any other utility) is for the "true up" bill, look at your net usage for the year. If it is positive (meaning you used more than you generated), then if you happen to have a credit balance that last period, they should pay out at the full, retail rate (or, alternatively, transform it into a monetary credit for the next year.) Only if you are net negative should they pay out at the wholesale rate the amount of credit that exceeds your annual usage.

It is not the end of the world by any means, but it seems to go against the spirit of the net metering regulations. I'm guessing the difference will be in the area of $25/year for me (best estimate of the amount negative I would be in the spring through mid-April) but I could see that being a much bigger number for larger houses, and for ones right at the 100% of usage region. And it is a big payday for the utilities across all their customers with solar.
 

BrettS

Active Member
Mar 28, 2017
2,129
2,540
Orlando, FL
That is a bummer, if that payout is at the wholesale rate. To me, what they should do (PEPCO, Potomac Edison, Duke, or any other utility) is for the "true up" bill, look at your net usage for the year. If it is positive (meaning you used more than you generated), then if you happen to have a credit balance that last period, they should pay out at the full, retail rate (or, alternatively, transform it into a monetary credit for the next year.) Only if you are net negative should they pay out at the wholesale rate the amount of credit that exceeds your annual usage.

That seems like a reasonable way to do it. That way you can still get full credit for all the power that you produce and use and still pay as you go.

Or even have a rolling 12 month period. For example, any excess power produced in April 2020 would need to be used by April 2021. Any excess power produced in May 2020 would need to be used by May 2021. It might be a little harder to track, but unless you have a really oversized system you shouldn’t have to worry about much excess.

It definitely does seem to vary by state. Here is the note about how Duke Energy in Indiana works:

Indiana
When a solar panel system generates more energy than supplied by Duke Energy, the customer is credited the excess kWh in the next billing cycle. These credits never expire, but if the customer discontinues net metering, all excess credits are granted to Duke Energy. The customer is separately responsible for paying the monthly connection charge.

I wouldn’t be against this option, really. It’s a bit less than ideal if your system is producing more power than you use in that eventually you’ll probably lose those credits. But at the same time you could get an EV (or charge your friend’s EV’s) to use them up before you move.
 

wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
That seems like a reasonable way to do it. That way you can still get full credit for all the power that you produce and use and still pay as you go.

Or even have a rolling 12 month period. For example, any excess power produced in April 2020 would need to be used by April 2021. Any excess power produced in May 2020 would need to be used by May 2021. It might be a little harder to track, but unless you have a really oversized system you shouldn’t have to worry about much excess.

It definitely does seem to vary by state. Here is the note about how Duke Energy in Indiana works:



I wouldn’t be against this option, really. It’s a bit less than ideal if your system is producing more power than you use in that eventually you’ll probably lose those credits. But at the same time you could get an EV (or charge your friend’s EV’s) to use them up before you move.

It definitely varies by state - as @GaitherBill noted, the net metering rule seems to be a MD PSC rule, and a very high percentage of utility rules are actually set by the state (and I think that is fairly common.) If I had a somewhat larger system, I would not like the IN rule because you get nothing for overproduction, but at least you know in advance and can plan for that (including potentially choosing to bank some production now against plans for a future EV, more use, or reduced generation as the system ages.) PEPCO in DC seems to have this same policy from what I can tell - credits do not expire but are never paid out.

The annual payout process is a bit difficult because weather in that last month in March/April can really affect the balance (as I am seeing with the unexpected, slight surplus I have for Sept/Oct due to the cooler weather.) I am not sure the selection of the month of April was necessarily done to hurt consumers - June might be the worst - but I think it would be better if they set the cutoff as the March bill instead. As you note, January is a bit early, but April - at least for me - is projected as the most net negative usage month, so it sucks to see it potentially get immediately paid out instead of banked against my summer usage.
 

Redhill_qik

Member
Aug 16, 2020
315
224
South SF Bay, California
The annual payout process is a bit difficult because weather in that last month in March/April can really affect the balance (as I am seeing with the unexpected, slight surplus I have for Sept/Oct due to the cooler weather.)

It really doesn't matter what month it ends/stops on as every day and month is in the 12 month period. Cycles from 1/1 to 12/31, 5/1 to 4/30, or 9/1 to 8/31 all have same 365 days in them with the same amount of sunlight and temperatures which will result in the same net result over the course of the year. The energy that you are consuming in July to run the AC that drives your net balance lower is the same regardless of the year ending on 7/31 or on 4/30.
 

wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
It really doesn't matter what month it ends/stops on as every day and month is in the 12 month period. Cycles from 1/1 to 12/31, 5/1 to 4/30, or 9/1 to 8/31 all have same 365 days in them with the same amount of sunlight and temperatures which will result in the same net result over the course of the year. The energy that you are consuming in July to run the AC that drives your net balance lower is the same regardless of the year ending on 7/31 or on 4/30.

It does matter if your utility automatically pays out credits at the wholesale rate at the end of the fiscal year and if that is based on your current credit level, not your total for the year.

As an example, suppose my bill has 4 quarters (to simplify,) roughly based on my home: Q1 = 300 kWh net use; Q2 = -600 net use (net production); Q3 = 1000 net use; Q4 = 400 net use.

My total usage is 1100, so you might think that is all that matters, regardless of the cutoff. However, the discussion seems to be that utilities don't necessarily look at it that way. So, if the utility cuts off at the end of Q1, the math is:
  1. After Q2, annual use to date is -600. Receive bill credit.
  2. After Q3, annual use to date is +400. Bill reduced due to prior credit. Credit is now 0.
  3. After Q4, annual use to date is +800. No bill reduction. Credit is 0.
  4. After Q1, annual use to date is +1100. No bill reduction. Credit is 0.
So, the utility pays me nothing, and we start over. However, if they cut off at the end of Q2 instead, the math may be:
  1. After Q3, annual use to date is +1000. No bill reduction. Credit is 0.
  2. After Q4, annual use to date is +1400. No bill reduction. Credit is 0.
  3. After Q1, annual use to date is +1700. No bill reduction. Credit is 0.
  4. After Q2, annual use to date is +1100. Receive bill credit of -600.
The problem is, it appears PEPCO (and other utilities) will immediately pay out that 600 kWh at the wholesale rate, rather than letting me carry it to the next year or recognizing that while I was -600 this quarter, I was +1100 for the year, so they should pay me at the retail rate. The basic issue is there is apparently no way to have a "negative credit" so the timing of when you receive and use credits throughout the year does matter. (I am still hoping it will turn out PEPCO does account for this, but it is not at all clear that they do.)
 

BrettS

Active Member
Mar 28, 2017
2,129
2,540
Orlando, FL
It really doesn't matter what month it ends/stops on as every day and month is in the 12 month period. Cycles from 1/1 to 12/31, 5/1 to 4/30, or 9/1 to 8/31 all have same 365 days in them with the same amount of sunlight and temperatures which will result in the same net result over the course of the year. The energy that you are consuming in July to run the AC that drives your net balance lower is the same regardless of the year ending on 7/31 or on 4/30.

The problem is that with my utility, at least, I need to pay for any power I use as I go, but I only get credit for power I generate after I generate it. So in my case the cycle starts in Jan. But Jan and Feb are low production months, so it’s likely that I’ll use some power from the grid during those months. And I need to pay for the power that I use on the Jan and Feb bills. Then as spring and summer comes I’ll start generating more power than I use, so at that point I’ll start building up credits. Then in November and December I’ll be producing less, so I can some of the credits I’ve been building up for those bills.

But then at the end of December the utility takes any excess credits that I have and pays me for them at the wholesale rates, then zero’s out my credits. So as I move in to Jan and Feb again I won’t have any credits to offset those bills, even though I potentially had plenty of credits left at the end of December. So even though my annual production might have been the same as my annual consumption I will have paid for power at retail rates in Jan and Feb and been refunded for credits that could have offset the Jan and Feb bills at wholesale rates in December.
 

Redhill_qik

Member
Aug 16, 2020
315
224
South SF Bay, California
It does matter if your utility automatically pays out credits at the wholesale rate at the end of the fiscal year and if that is based on your current credit level, not your total for the year.

As an example, suppose my bill has 4 quarters (to simplify,) roughly based on my home: Q1 = 300 kWh net use; Q2 = -600 net use (net production); Q3 = 1000 net use; Q4 = 400 net use.

My total usage is 1100, so you might think that is all that matters, regardless of the cutoff. However, the discussion seems to be that utilities don't necessarily look at it that way. So, if the utility cuts off at the end of Q1, the math is:
  1. After Q2, annual use to date is -600. Receive bill credit.
  2. After Q3, annual use to date is +400. Bill reduced due to prior credit. Credit is now 0.
  3. After Q4, annual use to date is +800. No bill reduction. Credit is 0.
  4. After Q1, annual use to date is +1100. No bill reduction. Credit is 0.
So, the utility pays me nothing, and we start over. However, if they cut off at the end of Q2 instead, the math may be:
  1. After Q3, annual use to date is +1000. No bill reduction. Credit is 0.
  2. After Q4, annual use to date is +1400. No bill reduction. Credit is 0.
  3. After Q1, annual use to date is +1700. No bill reduction. Credit is 0.
  4. After Q2, annual use to date is +1100. Receive bill credit of -600.
The problem is, it appears PEPCO (and other utilities) will immediately pay out that 600 kWh at the wholesale rate, rather than letting me carry it to the next year or recognizing that while I was -600 this quarter, I was +1100 for the year, so they should pay me at the retail rate. The basic issue is there is apparently no way to have a "negative credit" so the timing of when you receive and use credits throughout the year does matter. (I am still hoping it will turn out PEPCO does account for this, but it is not at all clear that they do.)

I'm not a PEPCO customer, but looking through their very slim documents on net metering I see this.

Are anniversary credits paid out by the District? No. Excess generation credits are applied to a customer's next bill as a dollar credit. Unused credit roll over to the next bill until fully used. Unlike in some neighboring states anniversary credits - a one-time annual payment of accumulated excess generation credits - are not paid in the District.

My reading of this is that generation and credits are month to month and if you oversized your system then you need to find a way to use that energy because you won't get paid for it.

Edit: I realized after I posted that the PDF that I was looking at said that it was for District of Columbia, but it also looks to be the same for Maryland.
 
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getakey

Active Member
Jan 28, 2020
1,413
451
95762
The problem is that with my utility, at least, I need to pay for any power I use as I go, but I only get credit for power I generate after I generate it. So in my case the cycle starts in Jan. But Jan and Feb are low production months, so it’s likely that I’ll use some power from the grid during those months. And I need to pay for the power that I use on the Jan and Feb bills. Then as spring and summer comes I’ll start generating more power than I use, so at that point I’ll start building up credits. Then in November and December I’ll be producing less, so I can some of the credits I’ve been building up for those bills.

But then at the end of December the utility takes any excess credits that I have and pays me for them at the wholesale rates, then zero’s out my credits. So as I move in to Jan and Feb again I won’t have any credits to offset those bills, even though I potentially had plenty of credits left at the end of December. So even though my annual production might have been the same as my annual consumption I will have paid for power at retail rates in Jan and Feb and been refunded for credits that could have offset the Jan and Feb bills at wholesale rates in December.

I don't understand the pay as you go part. For PG&E, we only pay for power in the annual true-up bill. Well, there are some "non-bypassable charges" at 2 or 3 cents per kWh that I pay monthly. However, they track credit/debit by month for each rate period and only pay for the power at true up. Duke's policy is really screwing you over. That said, your rates are way lower than ours
 

wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
I'm not a PEPCO customer, but looking through their very slim documents on net metering I see this.

Are anniversary credits paid out by the District? No. Excess generation credits are applied to a customer's next bill as a dollar credit. Unused credit roll over to the next bill until fully used. Unlike in some neighboring states anniversary credits - a one-time annual payment of accumulated excess generation credits - are not paid in the District.

My reading of this is that generation and credits are month to month and if you oversized your system then you need to find a way to use that energy because you won't get paid for it.

Edit: I realized after I posted that the PDF that I was looking at said that it was for District of Columbia, but it also looks to be the same for Maryland.
Yes, that PDF refers to DC, which I noted is like the Duke example for Indiana in terms of the policy. MD is not the same - the ever-so-exciting Public Utilities Code, Section 7-306 specifies:
On or before 30 days after the billing cycle that is complete immediately prior to the end of April of each year, the electric company shall pay each eligible customer-generator for the dollar value of any accrued net excess generation remaining at the end of the previous 12-month period ending with the billing cycle that is complete immediately prior to the end of April.

(2017 Maryland Code :: Public Utilities :: Division I - Public Services and Utilities :: Title 7 - Gas, Electric, and Water Companies :: Subtitle 3 - Consumer Relations :: § 7-306. Net energy metering)

The issue is "accrued net excess generation" is defined, as best I can understand it, such that if your April bill has excess generation, it cannot be offset against against January or February's bill - instead it is paid to you at the "generation or commodity portion of the rate".
 
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wjgjr

Active Member
May 11, 2020
1,305
1,037
Silver Spring, MD
I don't understand the pay as you go part. For PG&E, we only pay for power in the annual true-up bill. Well, there are some "non-bypassable charges" at 2 or 3 cents per kWh that I pay monthly. However, they track credit/debit by month for each rate period and only pay for the power at true up. Duke's policy is really screwing you over. That said, your rates are way lower than ours
It is the same in MD (I think with all utilities, but definitely PEPCO.) We pay for what we use when we use it. In some ways, I don't have an issue with it - that makes sense. However, the adjustment in this true-up bill should be that if you used more than you generated for the year, then your refund should be at the full net metering rate. However if it is less - meaning you over-produced - then the amount you over-produced would be paid out at the reduced rate (but any amount they owe you up to the amount generated would be at the full rate.)

Though I understand how they are intertwined, in some ways they are two issues, and Duke, PEPCO, or the state of MD could solve the one issue without removing the pay-as-you-go setup.

I am interested to see this month if we will still be charged the $8.50 monthly fee or if excess generation will offset that.
 

sleevemedia

Member
Jul 1, 2020
57
41
Orlando
This is the published tariff, but it doesn't show the COG-1 rate. https://www.duke-energy.com/_/media...es-fl/retail-rates-by-rate-schedule.pdf?la=en

My February bill has a line item on it labeled Net metering annual unused energy credit. For 16 cents. Elsewhere on the same bill, my net metering summary shows that I have 1,710 kWh as a carried forward balance. So I've been on hold with Duke since forever twice today, and in the process of trying to figure out what COG-1 is, I landed back here where it all started.

Eventually, DEF will answer the phone and I'll figure why the ridiculous "annual" credit and why the carry forward didn't reset.
---
Here's the download from Duke Renewables. Cutoff is the November billing period. That month, my PTO month, I had 8 excess kWh, at 1.9 cents COG-1 rate, resulting in 16 cents credit. For DEF customers, December and January excess production remains in the carried forward balance for the new year even though we don't see the annual credit until the bill we receive in February (that actually covers December 28 to January 28).

In my case, since I don't have an EV yet, and because I oversized my system in anticipation of buying one in a couple of years, I carry forward a lot of December through April production with very little heat and no cooling costs as production grows with longer days and better sun angle.
 
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