ERCOT Ancillary Services — Regulation, Reserves, and ECRS
Key Takeaway
ERCOT ancillary services include Regulation Up/Down, Responsive Reserve (RRS), Non-Spinning Reserve, ECRS, and Fast Frequency Response — procured to maintain grid reliability.
Quick Answer
ERCOT procures ancillary services to maintain grid reliability: Regulation Up/Down (AGC frequency control), Responsive Reserve Service (30-second frequency response), Non-Spinning Reserve (30-minute availability), ECRS (10-minute contingency), and Fast Frequency Response (sub-second from batteries/inverters).
Service Types
| Service | Response Time | Purpose |
|---|---|---|
| Reg-Up/Down | Seconds (AGC) | Continuous frequency regulation |
| RRS | 30 seconds | Sudden generation loss response |
| Non-Spin | 30 minutes | Reserve capacity, not synchronized |
| ECRS | 10 minutes | Contingency reserve (post-Uri) |
| FFR | Sub-second | Inverter-based frequency response |
ORDC
The Operating Reserve Demand Curve adds a scarcity premium to real-time prices as reserves decline. ORDC can add thousands of $/MWh at low reserve levels.
Industrial Demand Response
Large loads can register as Controllable Load Resources (CLRs) to provide Reg-Down and Non-Spin, earning capacity payments. See also the existing ERCOT demand response guide.
Frequently Asked Questions
Responsive Reserve Service — 30-second frequency response including fast-ramping generators and load resources that trip on under-frequency.
The Operating Reserve Demand Curve — an adder to real-time energy prices that increases as operating reserves decline, signaling scarcity before actual load shedding.
Yes. Large loads can register as CLRs and provide Reg-Down and Non-Spin, earning capacity payments.