Please provide your organization's comments on the FERC 881 - Managing Transmission Line Ratings May 24 stakeholder call discussion:
SCE commends the CAISO for initiating this stakeholder process to address the myriad issues to implement the requirements of FERC Order 881. SCE looks forward to coordinating with the CAISO to ensure a timely and effective implementation of Ambient Adjusted Ratings (AARs). SCE appreciates the opportunity to comment on the CAISO’s proposals regarding implementation of FERC Order 881 and provides its responses to the issues raised during the May 24 stakeholder call as follows (SCE lists the CAISO’s request based on the corresponding slide from the May 24 CAISO presentation):
CAISO Request: Do stakeholders have a different view and believe modifications to the TCA are necessary
SCE agrees there is no need to modify the TCA
Section 29.17 of the CAISO tariff require each WEIM Entity to submit transmission service information to the CAISO
CAISO Request: Do stakeholders have a different view and believe changes to Section 29 of the CAISO tariff are necessary?
SCE agrees there is no need to modify Section 29 of the CAISO tariff.
Section 19.5(b)(2) of the CAISO tariff requires each RC Customer to exchanging data, operating plans, operating procedures, studies, and reports with the CAISO in accordance with the Business Practice Manual for RC Services and applicable RC Operating Procedures
CAISO Request: Do stakeholders have a different view and believe changes to Section 19 of the CAISO tariff are necessary?
SCE agrees there are no revisions needed to Section 19 of the CAISO tariff.
- CAISO proposes to adapt the pro forma OATT language state that it will coordinate with participating transmission owners in their development of transmission line methodologies
- CAISO will also coordinate with participating transmission owners on the development of exceptions and alternate ratings
- CAISO is not proposing to create methodology requirements for participating transmission owners or WEIM Entities
CAISO Request: Do stakeholders have a different view and believe the CAISO must create methodology requirements that apply to participating transmission owners or WEIM Entities?
SCE strongly supports the CAISO’s position in coordinating with participating transmission owners on the development of exceptions criteria, development of alternate ratings and the development and implementation methodologies of transmission ratings for all transmission facilities as described in FERC Order 881.
- CAISO will propose to require submission of ambient adjusted ratings by market close to allow time for CAISO validation and market systems to utilize ratings
CAISO Request: Do stakeholders have any perspective on the use of ambient adjusted ratings in the CAISO’s markets or the timing to incorporate ratings
SCE is unclear of how the CAISO will use the ambient adjusted ratings (AARs) in the Day Ahead (DA) and Real-Time (RT) markets, as well as how the transmission owner will transfer this data to the CAISO. SCE asks for further explanation on how the usage of AAR data will be operationalized in the DA and RT markets.
- CAISO will also propose participating transmission owners validate ambient adjusted ratings prior to submission – Request: Does this proposed requirement create any stakeholder concerns
CAISO Request: Does this proposed requirement create any stakeholder concerns
SCE is unclear of the validation process and details of the CAISO proposal where participating transmission owners validate ambient adjusted ratings prior to submission. SCE expects that these details will be addressed during the CAISO-led implementation discussions and activities, including further explanation and clarification on the validation requirements and guidelines.
- CAISO will use seasonal rating if data or system issues prevent use of ambient adjusted rating
In the absence of the required AAR data submission, SCE asks if it would be better suited to use the most recently submitted AAR ratings such as the prior day or the prior week’s data, rather than seasonal ratings. Further explanation on the use of seasonal ratings such as use cases etc. would be appreciated.
The CAISO proposes to use ambient adjusted ratings from the real-time market in its real-time contingency analysis
- CAISO proposes to reflect the most granular ambient adjusted ratings used in the market as part of its RTCA during that same time interval
CAISO Request: Do stakeholders have any perspective on which ratings to use in RTCA, or potential variance between CAISO and participant RTCAs
SCE requests the CAISO clarify what is meant by the “most granular ambient adjusted ratings” as part of its RTCA analysis. SCE is unclear on how this will affect the RTCA analysis and what the ratings will be used in its RTCA analysis. SCE also asks for further explanation on how the RTCA analysis will be coordinated with the Transmission Owners.
CAISO Request: The CAISO requests stakeholder comment on the planned utilization of ambient adjusted ratings in remedial action schemes
SCE’s position is RAS schemes should not be required to incorporate AARs in their operations. Currently, it is infeasible for SCE to implement AARs in our RAS schemes within the timeframe allocated by FERC Order 881. Moreover, the potential benefits of using AARs on RAS schemes would not justify the implementation effort.
Seasonal ratings will apply to any long-term transmission service provided by the CAISO
- The CAISO is holding working group meetings to foster dialogue on the development of long-term transmission products and reservations, i.e. requests for transmission service more than 10 days in the future
- Seasonal rating methodologies would apply to these request for transmission service
CAISO Request: Do stakeholders have any comments on how, if at all, the CAISO should address this issue in its Order No. 881 compliance filing?
SCE’s assumption is that seasonal ratings would be used for most long-term transmission planning studies and requirements.
Order No. 881 requires the CAISO to implement systems and procedures necessary to allow electronic updates to ratings at least hourly
- Ratings submitted by participating transmission owners directly into the EMS through SCADA or similar systems
- Use of other electronic systems, such as Inter-Control Center Communication Protocol (ICCP)
CAISO Request: Do stakeholders have any perspectives on allowing both functionalities to accommodate PTOs, EIM Entities and RC Customers?
SCE does not have any concerns with using both functionalities to accommodate PTOs, EIM Entities and RC Customers. However, SCE will need to ascertain the technical viability of using these methods to communicate AAR data via the ICCP Protocol and EMS / SCADA systems due to the volume of data. SCE foresees significant technical challenges with achieving seamless data transfer using these two functionalities.
SCE also seeks clarification on how the CAISO would accommodate other stakeholders and what these accommodations mean in terms of data communication.
CAISO Request: Do stakeholders have perspectives on whether the CAISO should include tariff language governing dynamic line ratings, e.g. a definition and language recognizing dynamic line ratings in transmission rating methodologies?
SCE recommends excluding tariff language governing Dynamic Line Ratings (DLRs) until the FERC NOI proceeding on DLRs has been concluded or there is ultimately a requirement to implement DLRs as part of FERC’s transmission planning and cost allocation and generator interconnection NOPR.
Order No. 881 requires the CAISO maintain a database of ratings and methodologies on OASIS or another password-protected website
- Share ratings and methodologies with Transmission Providers, Market Monitor and other entities
- Maintain database of ratings used and methodologies as well as exceptions and alternate ratings
- Individual records of ratings in effect for each transmission line at which times
- Maintain records for 5 years
- CAISO proposes to limit this database to ratings and methodologies of participating transmission owners and not include EIM Entities or RC Customers
CAISO Request: Do stakeholders have any comments on these compliance requirements the CAISO should consider?
SCE concurs with the CAISO on the compliance requirements stated above.