What must be reported if there is a change in flow of ≥ 100 MW at ≥ 500 kV?

The requirement to report a change in flow of ≥ 100 MW at ≥ 500 kV specifically pertains to transmission flow. Transmission flow refers to the amount of electrical power transmitted through transmission lines, and it is crucial for maintaining system reliability and operability. When changes of this magnitude occur, they can significantly impact the stability of the electric grid, necessitating immediate reporting to ensure that system operators are aware of the current conditions.

Understanding and monitoring transmission flow helps in managing grid resources and forecasting potential overloads or other operational issues. Accurate reporting facilitates timely responses to any changes, which is essential for grid reliability. This context underscores the importance of transmission flow as a metric in the monitoring and management of electricity networks at high voltages.