Provide comments on the RAS Design guidelines such as SPS 6 & 7. A) Do the current guidelines give enough information regarding the design of the new RAS? B) If not, what are the suggested enhancements? C) Should some of the guidelines be converted to mandatory ISO planning standards?
A) Do the current guidelines give enough information regarding the design of the new RAS?
EDF-R believes the guidelines could be improved.
B) If not, what are the suggested enhancements?
It is EDF-R’s understanding that often the use of RAS is preferred not only for economics but for time. EDF-R appreciates these opportunities and regards RAS and other grid enhancing technologies and opportunities to maximize existing transmission and interconnect generation on an expeditious schedule. But if a RAS needs to be armed well above CAISO guidelines to accommodate generation in the area, EDF-R posits that the RAS is not the best long term solution. CAISO’s planning standards and SPS guideline 6 indicates “The SPS must be simple and manageable.” Though these terms are subjective, EDF-R suggests that an oversubscribed RAS or a nested RAS is neither simple nor manageable and that the guidelines should be amended to include examples of unacceptable scenarios.
C) Should some of the guidelines be converted to mandatory ISO planning standards? *
EDF-R suggests that CAISO planning standards should be amended to indicate that as supply increases and the transmission system changes, a RAS scheme that was previously the preferred solution may need to be replaced with a transmission solution. EDF-R suggests that CAISO planning standards should require an annual assessment of all existing and planned RAS, and that the Transmission Plan include in the existing list of RAS in the Transmission plan a new set of columns indicating:
- Confirmation that each RAS is still the best long-term solution given the expected level of generation in the area, and
- An assessment of how well the SPS manages the planning year’s scenarios (for example: very well, sufficient, poorly)
- If managing outages in the area are becoming “unmanageable”
- What the alternative transmission solution would be, including the timeline to construct
Publishing this data on the existing and planned RAS will provide an efficient look ahead (and look back) on RAS sufficiency. When RAS are poorly managing scenarios, CAISO the planning area narrative should include justification for the RAS remains in place, or a suggestion for reconfiguration or new transmission.
Are there any other RAS-related issues that need to be captured in the Issue Paper?
Protection from Risk for Existing and In-Flight Generation
In the policy paper CAISO states that “As a result, the amount of generation that was connected and available to be armed to these RAS exceeds the planning guidelines” and on the stakeholder call CAISO described that some RAS are oversubscribed by as much as 1000 MW and that some RAS are nested within other RAS. Existing generation and in-flight development are dependent on existing and planned RAS. Disruption of these RAS is quite likely to create subsequent disruptions in facility operations and RA contracting. EDF-R requests that CAISO does not modify or further restrict the use of RAS until comparable or better solutions are in place, and that any changes to existing or in-flight RAS are widely socialized with affected generators.
At a minimum “in-flight generation” should be defined as generation with an executed Generator Interconnection Agreement. At that stage in development interconnection customers have a reasonable expectation that project interconnection plans are basically firm and established.
Furthermore, EDF-R requests CAISO provide empirical data and examples of how any change proposed by CAISO would impact curtailment across generators participating or not into a RAS, and LMP signals. In particular, for oversubscribed RAS, how would modifying existing RAS to a fixed set of generators affect curtailment of generators in the RAS and market signals, and how the oversubscription being accounted for in operations, transmission and interconnection processes and studies?
Considerations for the TPP
Consistent with other comments in this document and elsewhere, EDF-R encourages CAISO to consider limiting the use of RAS in the future. EDF-R believes that it is clear that California is in need of more transmission to enable interconnection to the transmission system and based on operations observations and RAS planning standards in other ISOs that RAS has the effect of masking transmission needs. EDF-R cautions that it is inappropriate that future interconnection projects could bear the cost of major upgrades historically forgone due to CAISO’s planning guidelines and RAS oversubscription. Such costs are more appropriately borne by the TPP.
With respect to specific projects and RAS, EDF-R encourages CAISO to look at what is needed to resolve 500kv Devers-Colorado Rivers congestion and RAS in this year's TPP. RAS use in this area is widespread, already limiting generation, and immediate review is sensible.
Fictitious Bus Solution
Before providing an opinion on CAISO’s suggestion to create separate fictitious buses so that generation on RAS is not on the same bus as generation that is not on RAS EDF-R would like to better understand potential impacts of this. Once online all generation should be treated equitably by the market model transmission system. Is it just and reasonable for generators that are otherwise similarly situated to be subject to different treatment because of the RAS? Similarly, EDF-R is reluctant to endorse any fuel-type based treatment to identify which generators would be subscribed to the RAS, such a policy appears to be discriminatory. If CAISO decides to include this as a possible solution in the straw proposal, EDF-R requests CAISO provide empirical data and model how the fictious bus solution would affect curtailment and LMP signals.
Changes to single and double contingency limits
EDF-R requests more detail on the possibility of CAISO changing the single contingency (1100 MW0 and double contingency (1400) amounts. For most items in the paper CAISO presented possible solution sets for stakeholder consideration, but not for the contingency item. EDF-R would like to better understand the potential benefits or concerns with raising or lowering the contingency limits, and if any other guidelines or planning standards (NERC, WECC, etc) besides inform the limits.
Implementation of new standards
EDF-R requests CAISO provide with its next paper a table illustrating when and where new RAS standards will be implemented:
- Which TPP planning cycle will first use the new standards? 2022-2023? Or 2023-2024?
- Will the new RAS standards apply to Cluster 14 studies? Or start with cluster 15?
- What of CAISO’s recently published 20-year plan? How would new SPS guidelines shift those results, particularly in the scenario where tripping limits are reduced with the retirement of Diablo Canyon