What action should Balancing Authority ABC take after losing a generator at 0605?

In the context of a balancing authority experiencing a loss of generation at a specific time, the most appropriate action is to call the Regional Scheduler Group (RSG) for generation replacement. This is crucial because the immediate loss of a generator can lead to an imbalance between supply and demand on the electrical system.

By contacting the RSG, Balancing Authority ABC can explore options for securing replacement generation from other resources or neighboring entities. This ensures that generation is quickly restored to meet demand and maintain system stability, which is essential for reliability. The RSG typically has the necessary contacts and processes in place to facilitate timely generation adjustments.

The other options, while potentially useful in certain contexts, do not address the urgent need to replace lost generation as directly. Requesting additional generation immediately may not ensure a coordinated response, as it lacks the structured approach provided by RSG. Increasing operational efficiency or decreasing load demand, while they may help in the long run, do not directly and immediately address the critical situation following a generator loss.