Document ID: FERC-2019-1192-0001
Agency: ferc
Document Type: Notice
Title: Inviting Post-Technical Conference Comments: Managing Transmission Line Ratings
Posted Date: 2019-10-08T04:00Z

[Federal Register Volume 84, Number 195 (Tuesday, October 8, 2019)]
[Notices]
[Pages 53717-53718]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-21969]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. AD19-15-000]

Notice Inviting Post-Technical Conference Comments: Managing 
Transmission Line Ratings

    On September 10 and September 11, 2019, Federal Energy Regulatory 
Commission (Commission) staff convened a technical conference to 
discuss what transmission line ratings and related practices might 
constitute best practices, and what, if any, Commission action in these 
areas might be appropriate.
    All interested persons are invited to file initial and reply post-
technical workshop comments on any or all of the questions listed in 
the attachment to this Notice. Commenters may also respond to the 
questions outlined in the September 4, 2019 supplemental notice of 
technical conference.\1\ Commenters need not answer all of the 
questions. Commenters should organize responses consistent with the 
structure of the attached questions. Commenters are also invited to 
reference material previously filed in this docket, including technical 
workshop transcripts, but are encouraged to avoid repetition or 
replication of previous material. Initial comments must be submitted on 
or before 30 days from the date of this notice. Reply comments must be 
submitted on or before 15 days after the deadline to submit initial 
comments.
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    \1\ Available at https://www.ferc.gov/CalendarFiles/20190904173327-AD19-15-000supplTC.pdf.
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    For more information about this Notice, please contact:

Dillon Kolkmann (Technical Information), Office of Energy Policy and 
Information, Federal Energy Regulatory Commission, 888 First Street NE, 
Washington, DC 20426, (202) 502-8650, dillon.kolkmann@ferc.gov.
Kevin Ryan (Legal Information), Office of the General Counsel, Federal 
Energy Regulatory Commission, 888 First Street NE, Washington, DC 
20426, (202) 502-6840, kevin.ryan@ferc.gov.

    Dated: October 2, 2019.
Kimberly D. Bose,
Secretary.

Post-Technical Conference Questions for Comment

    Commenters may respond to the questions outlined in the September 
4, 2019 supplemental notice of technical conference.\2\ In addition, 
based on discussions during the Managing Transmission Line Ratings 
technical conference, Staff developed the following questions to better 
understand whether Commission action might be appropriate. To guide 
discussion, ambient-adjusted ratings (AAR) are defined as ratings that 
are adjusted daily, hourly, or more frequently and account for ambient 
air temperatures. Dynamic line ratings (DLRs) are defined as line 
ratings that are adjusted hourly or more frequently and account for 
local weather conditions (e.g., ambient temperature, wind, 
precipitation, solar irradiation) and/or account for conductor 
parameters (conductor temperature, tension, sag, clearance), typically 
as measured by local sensors.
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    \2\ Available at https://www.ferc.gov/CalendarFiles/20190904173327-AD19-15-000supplTC.pdf.
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1. Discussion of a Possible Requirement for Transmission Owners To 
Implement AARs

    a. Should transmission owners be required to implement AARs? If so, 
to which lines would the requirement apply? What criteria (e.g., 
congestion, facility age) and process would be used to determine to 
which lines the requirement would apply? What would be the benefits or 
drawbacks to such a requirement?
    b. If AARs are required, should they be required for modeling in 
both the day-ahead and real-time markets?
    c. What type of forecasting (e.g., how frequently, how granularly, 
and of what variables) is needed to incorporate AARs and DLRs into both 
real-time and day-ahead markets? If forecasts submitted in day-ahead 
markets differ from the real-time rating, how should

[[Page 53718]]

the difference be treated by the transmission system operator? Who is 
liable if forecasted ratings are wrong?
    d. Aside from ambient air temperature, are there other ambient 
conditions that can be forecasted or calculated without need for local 
sensors that should be considered in AARs? Should maximum possible 
solar irradiance intensity (conservatively calculated or forecast 
assuming no cloud cover) be included in calculation of any required 
AARs? Are there any instances where wind can be conservatively forecast 
without local sensors, such that wind should be considered in AARs for 
such lines?

2. Reducing Barriers to DLRs

    a. Can RTOs/ISOs currently accept and use a DLR data stream from a 
transmission owner in both real-time and day-ahead markets? Can 
transmission owners outside of RTO/ISOs currently automatically 
implement a DLR data stream in operations? Are there limits on what 
type and amount of data can be received and incorporated into dispatch? 
Would a transmission owner's or RTO/ISO's implementation of AARs be 
sufficient to also implement DLRs? If not, what additional changes 
would be necessary and how feasible are such changes?
    b. Would a requirement for transmission owners or other entities 
(e.g., RTOs/ISOs) to study the cost effectiveness of DLRs on their most 
congested lines be appropriate? If so, what metrics for congestion 
(e.g., congestion cost, hours of congestion) would be appropriate for 
determining the most congested lines?

3. AARs/DLRs in Available Transmission Capacity (ATC) Calculations

    a. In the non-RTO/ISO regions, a transmission owner's use of AARs 
could affect ATC for transmission customers. ATC could also be affected 
at RTO/ISO seams. Given the importance of ATC calculations, should 
AARs/DLRs be incorporated into the determination of ATC? Specifically:
    i. At what times in advance of transmission reservation and/or 
scheduling deadlines should ATC made possible through AARs/DLRs be made 
available to point-to-point and network customers?
    ii. Should AARs/DLRs affect when network customers (and the 
transmission provider's own resources) are subjected to redispatch, 
load shedding, and/or curtailments under sections 30.5 and 33 of the 
pro forma open access transmission tariff (OATT)?
    iii. Would any revisions be needed to section 30.5, section 33, or 
Attachment C of the pro forma OATT to accommodate a requirement to 
implement AARs or voluntary implementation of DLRs? Are there any other 
sections of the pro forma OATT that would be relevant to or affected by 
AAR/DLR implementation?

4. Discussion of Transparency of Transmission Line Rating Methodologies

    Currently, some transmission line rating methodology information is 
made available through certain transmission expansion processes or 
voluntarily on certain transmission owners' websites. Transmission line 
rating methodologies are also sometimes provided in annual FERC Form 
715 part 4 filings. Lastly, some RTO/ISOs post actual facility ratings 
on their open access same-time information system (OASIS) pages. 
However, there appear to be concerns about the inaccessibility of 
transmission line rating methodologies and resulting ratings.
    a. Should transmission owners' transmission line rating methodology 
be made more transparent? If so, how and how much additional 
transparency? Should underlying assumptions be made available? Should 
transmission line ratings be made more transparent? If so, how? For 
both transmission line rating methodologies and resulting ratings, who 
should have access to such information?
    b. Should transmission owners or other entities (e.g., NERC 
regional entities or RTOs/ISOs) be required to develop a database to 
document each transmission facility's most limiting element? Should 
limiting elements consider first and second contingency operating 
conditions? Please describe the burden associated with reporting and 
maintaining such a database. Who should have access to such a database 
and what levels of confidentiality protections would need to exist for 
such a limiting elements database?
    c. If a transmission system operator contacts a transmission owner 
to request an ad hoc increase in transmission line ratings above static 
or seasonal ratings, should information about the request be publicly 
posted? If so, where, when, and how often should such information be 
posted?

5. Review and Audit Procedures for Transmission Line Rating Practices

    a. Are the current review and audit procedures for transmission 
line ratings sufficient to ensure that such transmission line ratings 
are consistent with the methodology set forth by the transmission owner 
under FAC-008?
    b. What entities currently review or audit transmission line rating 
methodologies, assumptions, and values? What standards or criteria do 
these entities use in their reviews?
    c. What changes, if any, should be made to the review and audit 
procedures for transmission line ratings?
    d. What, if any, changes to information and document retention with 
respect to transmission line ratings might be needed?
    e. Where should any non-reliability criteria (e.g., economic) for 
transmission line ratings be established (e.g., regulations, tariff, 
policy statement)? What should these criteria be, and how would the 
Commission ensure that such criteria for transmission line ratings are 
consistent with reliability criteria?
    f. In implementing DLR, is there any data verification necessary 
from devices that measure DLR by the transmission system operators or 
transmission owners? If so, what data and why?

6. NERC Reliability Standards

    a. Are there security concerns associated with implementing AARs 
and DLRs with respect to communicating line ratings and field 
measurements?

[FR Doc. 2019-21969 Filed 10-7-19; 8:45 am]
BILLING CODE 6717-01-P