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acep-uaf / aetr-web-book-2024

Alaska Electricity Trends Report as a web book
https://acep-uaf.github.io/aetr-web-book-2024/
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Net generation totals for 2013-2020 have a missing component: MLP share of SPP #59

Open sgcolt562 opened 1 month ago

sgcolt562 commented 1 month ago

I noticed that the net gen time series for Railbelt drops conspicuously from 2012 to 2013 and bumps back up in 2021. Further investigation shows that reported sales exceed reported netgen in 2013, and they continue to do so in subsequent years after one adjusts for self-gen that starts becoming reported in 2014. The problem goes away in 2021.

Further investigation shows that MLP was NOT reporting on form 923 its 30% Share of SPP, while Chugach, the operator of SPP, was only reporting its 70% share. The problem goes away in 2021 because Chugach is merged with MLP for the full year.

Importantly, MLP DOES include its 30% share of SPP when reporting "net generation" on Form 861. The problem is their nonreporting on Form 923.

If the curators of these data wish, they could backfill the 2013-2020 data for MLP's share of SPP generation. Or, a footnote could be added somewhere.

jikaczmarski commented 1 month ago

@sgcolt562 Thanks for the in depth bug report. We will backfill the data with the missing self gen using Form 861 as soon as possible.

jikaczmarski commented 1 month ago

More context:

sgcolt562 commented 1 month ago

I thought it was a good chance to beta test the feedback mechanism. From my perspective as a "user" reporting an issue the system worked very well!

On Fri, May 24, 2024 at 1:24 PM Jesse Kaczmarski @.***> wrote:

@sgcolt562 https://github.com/sgcolt562 Thanks for the in depth bug report. We will backfill the data with the missing self gen using Form 861 as soon as possible.

— Reply to this email directly, view it on GitHub https://github.com/acep-uaf/aetr-web-book-2024/issues/59#issuecomment-2130382012, or unsubscribe https://github.com/notifications/unsubscribe-auth/A3GSUKL6F4OD2E6FQXAPMBTZD6VXDAVCNFSM6AAAAABHY2X2EWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCMZQGM4DEMBRGI . You are receiving this because you were mentioned.Message ID: @.***>

-- Steve Colt Research Professor Alaska Center for Energy and Power University of Alaska 907-301-6394

jikaczmarski commented 1 week ago

Just to provide an update

Because of this, I'm going to prepare a comparative analysis that looks at:

sgcolt562 commented 1 week ago

Excellent idea!

Steve Colt Research Professor Alaska Center for Energy and Power University of Alaska 907-301-6394

On Tue, Jun 18, 2024 at 1:44 PM Jesse Kaczmarski @.***> wrote:

Just to provide an update

  • The AK Energy Statistics Workbooks use EIA Form 923 for all generation tables.
  • The EIA923 form is missing the data that appears in EIA 861

Because of this, I'm going to prepare a comparative analysis that looks at:

  • Summing the EIA 923 power plant data to obtain net generation at the annual time step
  • Compare the annualized EIA 923 data with the annual EIA 861 net generation reported figures

— Reply to this email directly, view it on GitHub https://github.com/acep-uaf/aetr-web-book-2024/issues/59#issuecomment-2177107145, or unsubscribe https://github.com/notifications/unsubscribe-auth/A3GSUKKNCBVO6HHHEYKP35LZICS3PAVCNFSM6AAAAABHY2X2EWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCNZXGEYDOMJUGU . You are receiving this because you were mentioned.Message ID: @.***>

sgcolt562 commented 1 week ago

Excellent idea. The 861 has a great structure, I think, but coverage is sparse and it doesn’t say who purchased from and who sold to. If we could figure that out, wahoo!

Steve Colt Research Professor Alaska Center for Energy and Power University of Alaska 907-301-6394

On Tue, Jun 18, 2024 at 1:44 PM Jesse Kaczmarski @.***> wrote:

Just to provide an update

  • The AK Energy Statistics Workbooks use EIA Form 923 for all generation tables.
  • The EIA923 form is missing the data that appears in EIA 861

Because of this, I'm going to prepare a comparative analysis that looks at:

  • Summing the EIA 923 power plant data to obtain net generation at the annual time step
  • Compare the annualized EIA 923 data with the annual EIA 861 net generation reported figures

— Reply to this email directly, view it on GitHub https://github.com/acep-uaf/aetr-web-book-2024/issues/59#issuecomment-2177107145, or unsubscribe https://github.com/notifications/unsubscribe-auth/A3GSUKKNCBVO6HHHEYKP35LZICS3PAVCNFSM6AAAAABHY2X2EWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCNZXGEYDOMJUGU . You are receiving this because you were mentioned.Message ID: @.***>

jikaczmarski commented 1 week ago
I agree. I found that there are pretty significant difference between the data from EIA923 that we use (it's the only way the workbooks were able to produce stats by fuel code and prime mover type) and the utility's EIA861 reports. Below is an example from the 2019 data. Note that not all those who submit EIA923 also submit EIA861. Index Utility Id Utility Name EIA 861 Net Generation EIA 923 Net Generation Percent Difference
1 213 Alaska Electric Light&Power Co 123203 358105.00 190.66
2 221 Alaska Village Elec Coop, Inc 127782 112251.00 -12.15
3 599 Anchorage Municipal Light and Power 1125455 831896.89 -26.08
4 1276 Barrow Utils & Elec Coop, Inc 50047 47567.00 -4.96
5 3522 Chugach Electric Assn Inc 960771 899090.00 -6.42
6 4329 Copper Valley Elec Assn, Inc 95982 96218.00 0.25
7 6915 Galena Electric Utility 6147 5886.00 -4.25
8 7353 Golden Valley Elec Assn Inc 843857 840234.00 -0.43
9 9188 I-N-N Electric Coop, Inc 3753 3388.00 -9.73
10 10210 Ketchikan Public Utilities 113109 100277.00 -11.34
11 10433 Kodiak Electric Assn Inc 147524 149162.00 1.11
12 10451 Kotzebue Electric Assn Inc 20368 22149.93 8.75
13 11824 Matanuska Electric Assn Inc 755465 723815.00 -4.19
14 12119 McGrath Light & Power Co 0 1556.00 Inf
15 12385 Metlakatla Power & Light 17383 17384.00 0.01
16 13642 Nome Joint Utility Systems 30182 32649.00 8.17
17 13870 Nushagak Electric Coop, Inc 18663 18663.00 0.00
18 14856 Petersburg Borough - (AK) 14488 12940.00 -10.68
19 17271 City & Borough of Sitka - (AK) 109927 109927.00 0.00
20 18963 Inside Passage Elec Coop, Inc 9441 8188.00 -13.27
21 19454 City of Unalaska - (AK) 54273 54192.62 -0.15
22 19558 Homer Electric Assn Inc 118 705708.00 597957.63
23 21015 City of Wrangell - (AK) 614 612.00 -0.33
24 26616 North Slope Borough Power & Light 34910 34905.00 -0.01
25 29297 Pelican Utility 1273 1055.00 -17.12
26 40215 Cordova Electric Coop, Inc 26210 25915.00 -1.13
27 40548 Unalakleet Valley Elec Coop 4287 3166.00 -26.15

I'm starting to think that the size of the differences are so substantial that we may be misinterpreting the data in some way. To further investigate, I've reached out to EIA's electricity data expert hotline. I've had lots of success with past projects, so my fingers are crossed that they will have a lot to say about the differences. In the meantime, we're going to pursue a funding source that would allow us to really investigate these issues more diligently. I will also place a disclaimer on the net generation page (the only page that uses EIA923).

sgcolt562 commented 1 week ago

You know about Homer, Alaska Energy & Electric Coop generates all their power for purposes of 923.

On Wed, Jun 19, 2024 at 8:33 AM Jesse Kaczmarski @.***> wrote:

I agree. I found that there are pretty significant difference between the data from EIA923 that we use (it's the only way the workbooks were able to produce stats by fuel code and prime mover type) and the utility's EIA861 reports. Below is an example from the 2019 data. Note that not all those who submit EIA923 also submit EIA861. Index Utility Id Utility Name EIA 923 Net Generation EIA 861 Net Generation Percent Difference 1 213 Alaska Electric Light&Power Co 123203 358105.00 190.66 2 221 Alaska Village Elec Coop, Inc 127782 112251.00 -12.15 3 599 Anchorage Municipal Light and Power 1125455 831896.89 -26.08 4 1276 Barrow Utils & Elec Coop, Inc 50047 47567.00 -4.96 5 3522 Chugach Electric Assn Inc 960771 899090.00 -6.42 6 4329 Copper Valley Elec Assn, Inc 95982 96218.00 0.25 7 6915 Galena Electric Utility 6147 5886.00 -4.25 8 7353 Golden Valley Elec Assn Inc 843857 840234.00 -0.43 9 9188 I-N-N Electric Coop, Inc 3753 3388.00 -9.73 10 10210 Ketchikan Public Utilities 113109 100277.00 -11.34 11 10433 Kodiak Electric Assn Inc 147524 149162.00 1.11 12 10451 Kotzebue Electric Assn Inc 20368 22149.93 8.75 13 11824 Matanuska Electric Assn Inc 755465 723815.00 -4.19 14 12119 McGrath Light & Power Co 0 1556.00 Inf 15 12385 Metlakatla Power & Light 17383 17384.00 0.01 16 13642 Nome Joint Utility Systems 30182 32649.00 8.17 17 13870 Nushagak Electric Coop, Inc 18663 18663.00 0.00 18 14856 Petersburg Borough - (AK) 14488 12940.00 -10.68 19 17271 City & Borough of Sitka - (AK) 109927 109927.00 0.00 20 18963 Inside Passage Elec Coop, Inc 9441 8188.00 -13.27 21 19454 City of Unalaska - (AK) 54273 54192.62 -0.15 22 19558 Homer Electric Assn Inc 118 705708.00 597957.63 23 21015 City of Wrangell - (AK) 614 612.00 -0.33 24 26616 North Slope Borough Power & Light 34910 34905.00 -0.01 25 29297 Pelican Utility 1273 1055.00 -17.12 26 40215 Cordova Electric Coop, Inc 26210 25915.00 -1.13 27 40548 Unalakleet Valley Elec Coop 4287 3166.00 -26.15

I'm starting to think that the size of the differences are so substantial that we may be misinterpreting the data in some way. To further investigate, I've reached out to EIA's electricity data expert hotline. I've had lots of success with past projects, so my fingers are crossed that they will have a lot to say about the differences. In the meantime, we're going to pursue a funding source that would allow us to really investigate these issues more diligently. I will also place a disclaimer on the net generation page (the only page that uses EIA923).

— Reply to this email directly, view it on GitHub https://github.com/acep-uaf/aetr-web-book-2024/issues/59#issuecomment-2179096511, or unsubscribe https://github.com/notifications/unsubscribe-auth/A3GSUKLU7QEXKPTUQWC3AMDZIGXD7AVCNFSM6AAAAABHY2X2EWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCNZZGA4TMNJRGE . You are receiving this because you were mentioned.Message ID: @.***>

-- Steve Colt Research Professor Alaska Center for Energy and Power University of Alaska 907-301-6394

jikaczmarski commented 1 week ago

Could you elaborate more?

jikaczmarski commented 1 week ago

I got some clarification from EIA I think it important, especially for your following comment:

Importantly, MLP DOES include its 30% share of SPP when reporting "net generation" on Form 861. The problem is their nonreporting on Form 923.

Only one entity can submit net generation figures on EIA-923 for a power plant/unit, regardless of ownership share. The submitter is supposed to report all 100% of the power plant's net generation on this form. This means that we will get differences in numbers if we compare 'net generation' from EIA-923, summed by utility, to EIA-861 due to the lack of information on share of net generation that goes to each. This is why there are such different numbers in the above table.

I went ahead and pulled the monthly 923 reporting data for SPP and here is a graph of net generation as reported by Chugach. I do see that there is a significant uptick in reported net generation after 2020,

net_generation_57036

To properly solve this problem, we would need to investigate how much missing net generation there is from Chugach's SPP reports on EIA-923.