1.
Please provide your organization’s feedback regarding the Extended Day-Ahead Market Tariff Clarification Matrix, which was posted on Nov 4th
Summary Comments:
The Energy Authority (TEA) appreciates the ongoing opportunity to provide feedback on CAISO’s EDAM Intertie Scheduling implementation plans as they have developed across multiple meetings from August 21 through November 14, 2025, and as they are addressed in the Tariff Clarifications proposed to be submitted to FERC in January 2026. We appreciate CAISO staff’s time in considering our revised and supplemental comments.
CAISO took two very important steps to simplify its EDAM go-live plans over the past few weeks to reduce EDAM scheduling seams with bilateral and other existing market expectations, which TEA strongly supports.
- Maintaining the status-quo “SP-Tie” model for pricing DA and HASP interchange schedules and mapping CAISO CRRs at CAISO’s interfaces; and
- Not requiring auto-mirroring of HASP schedules at CAISO’s interfaces, which would have effectively inserted a “hurdle rate” in the clearing of those CAISO-intertie HASP schedules.
TEA recommends, however, that CAISO make two additional adjustments to the EDAM intertie scheduling framework via its Tariff Clarifications process to reduce the economic exposure EDAM LSEs will have in the market and improve transaction efficiency for all entities making bilateral purchases and sales before the CAISO day-ahead market run:
- Extending the SP-Tie model to the non-CAISO EDAM BAA interface points with their adjacent BAAs to maintain pricing and scheduling conventions used today; and
- Using the SP-Tie model for all non-EDAM transactions at all CAISO interfaces.
TEA understands that CAISO has valid reasons for pursuing a GAP-Tie framework for its markets, however, TEA believes the commercial benefits of maintaining a SP-Tie model for all EDAM interfaces outweighs any potential tradeoffs in powerflow modeling accuracy in the DAM horizon.
TEA also recommends CAISO make an additional related adjustment prior to EDAM go-live to improve outcomes for EDAM LSEs and overall benefit the efficiency of the market.
- Enable EDAM BAs to provide Tier One congestion reversals to Non-Firm Network (6-NN) rightsholders in certain circumstances.
Each of the above adjustments to the EDAM model should remain in place until a package of EDAM Enhancements can be developed through a stakeholder process in 2026 and implemented when feasible in 2027 or 2028.
Finally, TEA requests CAISO revise its proposed Tariff Clarification in Section 33.31.3 and 33.31.3.2 regarding the EDAM Net EDAM Transfer Constraint (NETC) timeline by maintaining the defined targeted timeline for publishing the constraint information and moving that timeline earlier in the day-ahead market horizon, ideally to 0800 on OD-1 or sooner.
Detailed Comments:
Extending the SP-Tie Model to the Non-CAISO EDAM BAAs
TEA does not agree with CAISO’s assumption that the GAP-Tie model is appropriate in the day-ahead horizon for the non-CAISO EDAM areas simply because the WEIM uses that model for certain transfers in the real-time horizon. EDAM and WEIM are very different markets with different participation models and very different economics and market volumes. Use of the GAP-Tie model for the PacifiCorp and PGE BAAs will create price-formation and congestion price exposure issues for entities arranging firm energy hourly-block transactions outside of EDAM to meet load or generation priorities through transfers to or from an EDAM BAA at its EDAM External Interties. TEA therefore believes CAISO should encourage and support non-CAISO EDAM BAAs to use functionality for their areas that mirrors CAISO’s SP-Tie model for its BAA, at least until significant enhancements have been made to the EDAM Congestion Revenue Allocation (CRA) and congestion accrual policies. TEA does not view this as a step backward relative to WEIM modeling because EDAM is a new market and using the SP-Tie model in day-ahead and HASP would not prevent WEIM imbalance optimization between WEIM-only and EDAM areas from happening as today.
TEA is sympathetic to CAISO’s concerns that the systems-based and other implementation constraints the CAISO faces at this juncture may make it difficult to move to a SP-Tie model in time to adequately test systems prior to go-live. TEA also is aware that the GAP-Tie methodology in Appendix C of CAISO’s OATT was already approved by FERC in CAISO’s initial EDAM Tariff filing and therefore CAISO does not have a new “just and reasonable” threshold to meet if it wishes to maintain the GAP-Tie model for the non-CAISO EDAM areas. Nonetheless, we believe the effort it would take to move to a SP-Tie model for interchange transactions at the EDAM areas is worth undertaking at this time.
Using The SP-Tie Model For All Non-EDAM Transactions At All CAISO Interfaces
TEA does not support the changes proposed by CAISO regarding the scheduling of RA Imports sourced-from or wheeled-through an EDAM BAA or a WEIM BAA to reach a CAISO intertie. Rather than making changes to the Import RA bidding and scheduling framework, CAISO should make allowances within the EDAM model that permit these contracts to be fulfilled as they are today – from showing to bidding to pricing to scheduling – while meshing with the congestion revenue accrual and allocation model for the EDAM BAAs. Adjusting this treatment should not be complicated or conceptually foreign to CAISO as it currently supports the bidding of Import RA-associated energy schedules at its interties where transfer capacity is optimized separately for DA and HASP hourly-block schedules and residual imbalance optimization through WEIM using established ETSR capacity. If extending this functionality to Import RA schedules, it would be logical for CAISO to extend the same to all bilateral schedules, including those for economy energy imports as well as source-specific, RPS-eligible imports. EDAM Transfer System Resources (TSR) function similar to WEIM Energy Transfer System Resources (ETSR) in that they seek to optimize system-to-system capabilities rather than individual resources, and therefore it is logical to separate those transfers from import and export schedules in the day-ahead market that become resource specific once e-tagged as an individual transaction.
Enable EDAM BAs To Provide Tier One Congestion Reversals To 6-NN Rightsholders In Certain Circumstances
LSEs within an EDAM BAA have no choice but to be exposed to congestion price impacts when importing Firm energy using SSs if they are unable to secure 7-FN rights, register them with CAISO to receive a CRN, and reference that CRN in a balanced-SS transaction’s E-Tag. Despite stakeholder objections, CAISO and the EDAM BAAs developed Tariff language that failed to address the practical reality LSEs face regarding use of and billing for NT rights, particularly in the pre-DAM window where third-party LSEs will attempt to deal with outages, forecast error, and market economics as efficiently as possible prior to the EDAM RSE and EDAM optimization.
Specifically in the PacifiCorp East EDAM BAA, insufficient 7-F and 7-FN rights are available in the planning horizon to support all DNRs registered by the LSEs. In many instances, these LSEs have requested network upgrades and have been waiting years to receive Firm service rights. In others, upgrades have been deferred because relying on 6-NN rights has generally been reliable to date and there have not been meaningful economic trade-offs of doing so. Importantly, all LSEs are billed through their Network service agreements as if they receive Firm service for their entire DNR portfolio, as well as for whatever service is necessary to meeting their Coincident Peak (CP) demand.
For example, UAMPS is assigned transmission costs according to its 12-CP (i.e., monthly CP demand) and the relationship between its CP and the CPs of PacifiCorp’s other NT users, including its own LSE and others like UMPA, DGT, and BPA. UAMPS does not receive a discount for the portions of its CP that must be covered by 6-NN rights, nor does it pay an additional amount today for import schedules that use new 6-NN or redirected 7-FN rights.
The PacifiCorp Tariff and pro-forma OATT recognizes that LSEs are capped in their use of a provider’s transmission system by their measured demand and prevented in most instances from using these rights for anything other than load service (i.e., they cannot use 6-NN rights to support economy-energy off-system sales to third-parties). The OATT and other agreements therefore provide allowances for the use of 6-NN that prevent these LSEs from being disadvantaged in existing bilateral markets. As a result, LSEs like UAMPS primarily schedule economy-energy transactions using 6-NN rights in the market today.
Unfortunately, in attempting to create parallel treatment between wheeling customers’ 7-F Point-to-Point rights and 7-FN NT rights in EDAM, both the CAISO and PacifiCorp (as well as PGE) failed to recognize that the above realities would prevent EDAM LSEs from receiving equitable treatment in practice for their EDAM schedules that through no fault of their own must be executed on 6-NN rights. Despite intervenor objections, this asymmetrical treatment was allowed to be baked into EDAM Tariffs. It is this treatment that TEA believes should be unwound at this late hour through targeted Tariff adjustments and clarifications.
The simplest way to do this would be to amend the CAISO and EDAM Entity Tariffs to allow LSEs to register 6-NN rights to receive a CRN from CAISO that would make schedules associated with those 6-NN rights eligible for Tier One congestion allocation when specific requirements have been met, including:
- The transaction is SS in accordance with applicable Tariff or Service Agreement[1] rules at an EDAM External Intertie or as intra-change within the EDAM BAA in the DAM to serve EDAM LSE demand;
- The transaction is for Firm energy, i.e., a WSPP Schedule C Firm Energy product or equivalent;
- The transaction is appropriately accounted for in the ECP for EDAM RSE purposes; and
- The EDAM LSE has complied with all applicable NT rights usage rules under the EDAM Entity’s OATT.
TEA believes it is critical that CAISO and the EDAM BAAs support this treatment at least until a comprehensive redesign of the EDAM CRA policy can be undertaken and implemented. TEA is hopeful that redesign will include EDAM BAAs supporting economic intertie bidding without requiring association with demand or resources in an EDAM area, with a framework and incentives like what has been developed for the Markets+ day-ahead market. TEA is also hopeful a redesigned CRA policy will directly and fairly compensate transmission customers for their investment in an EDAM Entity’s transmission system, regardless whether they are scheduling on their NT or PTP ownership rights in any given interval (i.e., moving to a rights-based instead of use-based framework with direct settlement between CAISO and market participants)[2].
This is important for market equitability given that EDAM LSEs that are paying for full 7-FN network transmission service for their entire coincident peak demand have no choice but to rely on 6-NN transmission to deliver imported energy due to either a lack of available 7-FN rights on specific paths or an inability to complete the DNR process in time to receive 7-FN rights for WSPP Schedule C bilateral firm energy spot-market and near-term contracts;
Retaining and Adjusting EDAM NETC Provisions in Tariff Sections 33.31.3 and 33.31.3.2
TEA sees the NETC as clearly impacting “rates, terms, and conditions” of the market and therefore believes process parameters constraining its use should be in the Tariff. TEA expects the NETC will be used sparingly by operators; however, when it is used, it will likely have a meaningful impact on market clearing prices across the EDAM and persisting in the WEIM horizon. Given that the current EDAM Congestion Revenue Allocation policy limits non-CAISO EDAM areas’ market participants’ ability to hedge congestion component price risk without undermining market efficiency or increasing overall energy price risk[3], and also introduces additional underfunding risk to CRR positions in the CAISO EDAM area, it is very important that entities have as much information as possible to adjust their positions and hedge their risks with pre-DAM or intra-day bilaterally contracting when markets are most liquid and prior to EDAM compliance deadlines.
TEA therefore requests CAISO retain the existing expectation established in the Tariff that CAISO and/or EDAM Entity Operators communicate no later than 09:00a on OD-1 any plans to enact the NETC, absent a system emergency or immediate reliability threat. Ideally this would include at what level the NETC would be set and for what duration. This would be similar to the communication and transparency expectations CAISO meets when enacting a nomogram constraint, limiting convergence bidding at certain nodes, removing source-sink pairs from its CRR process, or making similar market-impacting decisions, all of which are communicated timely to market participants through OASIS or other means.
TEA and others suggested in the PacifiCorp Tariff development process that this deadline be moved up to 0800 or earlier, or even be set in the OD-2 horizon, to give market participants as much certainty as possible when they are making financially binding decisions to arrange supply and manage demand well in advance of the EDAM RSE binding compliance deadline or ideally in advance of the western bilateral market liquid day-ahead trading window (roughly 0600-0800).
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About TEA:
The Energy Authority is a nation-wide, non-profit, public-power owned provider of wholesale energy market services. In the West, TEA has partnered with load serving entities inside the CAISO BAA and those in external EDAM and WEIM BAAs to leverage CAISO’s markets to return value to their end-use consumers from their investments in generation and transmission assets. TEA has also partnered with the same to leverage the two SPP markets, RTO-Expansion and Markets+, which are going live in 2026 and 2027 respectively. TEA’s participation in these efforts is focused on CAISO and SPP developing practical solutions that enhance DA and RT market efficiency without undermining other aspects of the complex near- and long-term energy markets its customers engage with to meet their load-service and least-cost planning goals.
[1] Some PacifiCorp NT customers operate under a Transmission Service Operating Agreement (TSOA) that in certain areas supersedes PacifiCorp’s Pro-Forma OATT but is generally consistent with OATT treatment and transmission service available in other EDAM BAAs, as well as the CAISO’s treatment of its on-system resources and loads.
[2] TEA and many other stakeholders requested this treatment during PacifiCorp’s and PGE’s Tariff development process, and also suggested other remedies, but unfortunately were dismissed at the time. SPP’s Markets+ congestion revenue accrual and allocation framework is an example of a model that could work for EDAM, even with the structural market seams between CAISO’s full-market and the EDAM areas.
[3] TEA and its regional partners commented at length in the CAISO EDAM CRA Tariff effort this past summer and in PacifiCorp and PGE’s EDAM Tariff processes regarding the market impacts of the EDAM congestion accrual and allocation framework, which incentivizes self-scheduling of resources and prevents Network Transmission customers from receiving a fair hedge in the market for their significant funding of EDAM BA/TSP’s transmission revenue requirements. TEA looks forward to engaging with CAISO and other stakeholders soon on evolving the EDAM congestion accrual and allocation framework in the new CRA intiative.
