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If Dominion is not applying ELCC to thermal units, can you please explain the capacity value assumptions for those resources? The transmission study seems consequential to the impact of the resource builds, because the import/export constraints will significantly affect where or how much new capacity gets built. The assumptions within the transmission study (such as voltage concerns, stability issues, etc.) will drive these decisions. It would therefore be very helpful to understand the extent to which options like alternative transmission technologies, or near-term grid enhancing technologies are being considered.
Per the recommendations of the Commission Staff and the Hearing Examiner during the 2023 IRP case, Dominion Energy will utilize the PJM Effective Load Carrying Capacity (ELCC) study, published on April 24, 2024 (preliminary-elcc-class-ratings-for-period-2026-2027-through-2034-2035.ashx (pjm.com)), for use in the 2024 IRP modeling for all applicable resources in the IRP modeling.
The import/export transmission analysis is performed to estimate the transmission network's capability to import power into the Dominion Zone. The analysis uses similar study principles to PJM’s Regional Transmission Expansion Planning Process (RTEPP) and considers thermal and voltage equipment limits. The results of the import/export analysis represent one of many inputs into the IRP.
Dominion Energy, as a member of the PJM, participates in PJM’s FERC-approved RTEPP that is used to plan the enhancement and expansion of the transmission system. All transmission solutions including the construction of new transmission facilities, uprating of existing transmission facilities, and the application of grid-enhancing technologies (GETs) are considered in the RTEPP. The IRP can help identify possible transmission needs, but it is not intended to replicate the RTEPP analysis.