Which component is NOT part of operating reserves?

Operating reserves are critical components of a power system’s reliability, providing backup power that can be quickly accessed when needed. Synchronized reserves and non-synchronized reserves both fall under the umbrella of operating reserves. Synchronized reserves refer to those resources that can respond immediately to changes in demand or outages, while non-synchronized reserves typically involve resources that can be brought online with a slight delay. Supplemental reserves also function similarly, providing additional capacity that can be deployed in case of unexpected system demands.

The component labeled as "sustainable reserves" does not align with the definitions or categories typically recognized within operating reserves. Sustainable reserves may imply a focus on long-term renewable energy resources or stable generation that continually meets operational needs, but they are not a recognized subset of operating reserves as defined in power system operations. Therefore, this choice does not fit with the commonly accepted classifications within operating reserves, making it the correct answer in this context.