Which of the following is a characteristic of the AGC system?

The characteristic of the Automatic Generation Control (AGC) system that stands out is its effectiveness in real-time system management. AGC plays a crucial role in maintaining the balance between electricity supply and demand by automatically adjusting the output of generators. It helps manage real-time grid operations by responding to changes in load and frequency, ensuring that the supply of electricity aligns with the instantaneous demand. This capability allows grid operators to maintain stable operations while mitigating the risks associated with frequency deviations.

The other options do not accurately reflect the characteristics of the AGC system. The AGC operates continuously and is not limited to peak demand scenarios; it functions as needed to balance load throughout all times of the day. Additionally, AGC is designed to respond to frequency variations rather than functioning independently of them, as it relies on real-time data to adjust generator outputs accordingly. Lastly, AGC is not limited to hydroelectric plants; it can be applied across various types of generation resources, including thermal, renewable, and nuclear power facilities.