Essential Reliability Service Requirements from Utility-scale Solar and Wind in Bulk Power Markets

For decades, the inherent provision of Essential Reliability Services (ERS) by central, dispatchable generators led to an abundance of frequency and voltage support, such that planners and operators of the U.S. Bulk Power System (BPS) did not require robust techniques to monitor these attributes. This paradigm has shifted over the past two decades as reliability concerns from larger penetrations of variable energy resources (VERs) have emerged. Recent demonstrations of advancements in power electronics have shown that VERs are also capable of accurate and rapid response to grid disturbances. However, the ERS capabilities of VERs are limited by market structures and regulations designed for conventional resources. Utilizing the ERS framework developed by North American Electric Reliability Corporation (NERC), this report documents key discussions, demonstrations of ERS capability, market innovations, and updates to U.S. interconnection rules and reliability standards for VERs.