According to NERC requirements, what happens if reactive resources are insufficient during a voltage collapse situation?

In a voltage collapse situation, the primary concern is maintaining system reliability and stability. When reactive resources are insufficient to support voltage levels and ensure the stability of the electrical grid, the requirement is to shed firm load. Firm load refers to the load that is guaranteed to be served and cannot be curtailed without consequence. This is crucial because shedding firm load helps to stabilize the system by reducing demand, allowing the remaining resources to restore voltage levels and prevent a more significant collapse.

This action is performed to ensure that the stability of the electric grid is maintained and to prevent cascading failures that could lead to larger outages. Shedding only non-firm load would not be adequate in this scenario, as it may not sufficiently alleviate the stress on the system. Similarly, increasing load or reducing generation would exacerbate the problem, leading to further voltage issues. Therefore, the requirement to shed firm load is a necessary and strategic response to protect the overall integrity of the electric grid during a voltage collapse scenario.