The California Independent System Operator (CAISO) manages the flow of electricity across 80% of California and parts of Nevada. One of its main objectives is to ensure the frequency of power on the grid stays at around 60 Hz. It achieves this by procuring and deploying Ancillary Services.
But why does frequency change? And how do the Ancillary Services correct deviations in system frequency?
System frequency is the speed at which generators on the grid are spinning. If there’s an imbalance between generation and demand, some generators slow down or speed up, causing the frequency to shift.
Keeping the frequency close to 60 Hz makes sure the lights stay on.
Each Ancillary Service is designed to incentivize resources to adjust their output when the system needs it most. They secure capacity from resources to regulate the system frequency and reconcile short-term imbalances between supply and demand.
To read our beginner’s guide to ERCOT’s Ancillary Service, head here.
The entirety of this article is completely free to view - you just need to sign up for a free Modo Energy account. Find out:
- What CAISO’s main Ancillary Services (Regulation, Spinning Reserve, and Non-Spinning Reserve) actually do.
- The specific requirements of each service - in terms of duration and capacity.
- And when CAISO deploys each service.
What are CAISO’s Ancillary Services?
There are four main Ancillary Services: Regulation Up, Regulation Down, Spinning Reserve, and Non-Spinning Reserve.