What percentage is required for Black Start resources to meet the critical load requirement?

To understand the requirement for Black Start resources to meet critical load, it’s essential to realize that Black Start capability is designed to restore power after a system-wide outage. The purpose of having Black Start resources is to ensure that when the grid goes down, there are sufficient resources available to start up offline power plants and bring them back online in a systematic way.

Meeting the critical load requirement necessitates planning for potential contingencies and system losses to ensure reliability. Therefore, requiring 110% of the critical load means that the available Black Start resources must not only aim to meet the immediate needs of critical loads but also have a buffer. This buffer accounts for unexpected surges in demand or any delays in bringing additional resources online.

In practice, a target of 110% ensures that there is enough capacity to handle variations and guarantees that critical loads will be maintained, even if some resources are not available or operational. This extra percentage also supports resilience within the power system during restoration processes, which can often be unpredictable and complex.

Thus, the requirement for Black Start resources is set at 110% to provide a necessary cushion that maintains the integrity and reliability of the power supply during the challenging periods of system recovery.