Introduction by Curtis Holland about battery energy storage systems (BESS) in the Western Interconnection, covering parts of 14 states, 2 Canadian provinces, and Baja, Mexico.
Overview of the role and technology of BESS, including their connection via inverters and operation through a battery management system.
Statistics from the Energy Information Administration showing a significant increase in BESS capacity in California ISO and ERCOT.
Different uses and capabilities of BESS, such as system peak shaving and regulation, with emphasis on California ISO's adjustments to ramp rates.
Use case example of BESS during cold weather and its role during emergencies.
NERC’s study on disturbances affecting BESS, highlighting systemic vulnerabilities in inverter-based resources.
Detailed accounts of January 2024 cold weather event where BESS played a critical emergency role.
Discussion on the impact of protective logic failures in BESS operations and implications during system events.
Examples of unexpected BESS behaviors during grid events, highlighting the importance of correct control implementation and modeling.
Issues with BESS causing oscillations in the system and proposed improvements such as hardware in the loop testing.
Fire incidents associated with BESS and the challenges in extinguishing these fires, including significant ecological impacts and ongoing attention to these events.
Closing remarks highlighting key resources for understanding BESS and addressing audience questions on lessons learned in PFR coordination and control strategy issues in BESS.
Discussion around potential changes in interconnection requirements for BESS, specifically concerning hardware in the loop testing for identifying oscillations before integration.
Julia Matevosyan and Fred Huang address a recent interaction with ERCOT battery owners regarding aggressive frequency response settings and the need to meet required droop settings to prevent excessive battery drain.
▶️3 - HRL of a single resource vs an aggregated value of a defined IRR Group
Acciona Energy proposed allowing a single HRL value for grouped IRR units instead of individual HRLs to increase the stabilization of generation injection and reactive support.
The current system evaluates compliance at the group level, but individual units are limited by their registered HSL or HRL.
ERCOT Nodal Protocol Section 3.8.7 Self-Limiting Facilities, introduced recently with NPRR1026, may be relevant to the scenario.
Self-limiting facilities are required to operate within agreed upon power limits at the POI.
ERCOT is conducting internal discussions and plans to gather site-specific details to further evaluate the proposal.
A follow-up meeting with Acciona representatives is planned to discuss site-specific details offline.
Issues arise with solar plants having more units but being limited at the transformer level, affecting injection capacity.
Acciona found similar plants in different regions with varying energy injection capabilities.
Future Actions:
ERCOT to reach out to entities for site-specific details to potentially apply self-limiting protocol to IRR groups.
Ismael Moral Díaz and Jose Villarreal from Acciona will coordinate with Abhi Masanna Gari from ERCOT for further offline discussions.
Possibility of another meeting to discuss resolutions and share with the working group.
Additional Comments:
Jose Villarreal from Acciona emphasized that the self-limiting facilities option may not fully resolve the issue.
Acknowledged the opportunity to inject more energy from solar plants in the system.
Acknowledgement of growing energy demand and the importance of optimizing solar energy injection.
