ERCOT FFR Dispatch Timeline
How a grid-following BESS turns an under-frequency trigger into delivered fast frequency response.
ERCOT FFR Dispatch Timeline
How a grid-following BESS turns an under-frequency trigger into delivered fast frequency response.
Control visualization - autoplay the under-frequency event, scrub the timeline, and check whether full response lands inside the ERCOT 0.25 s FFR window.
What it shows
The timeline follows an under-frequency event from the moment grid frequency crosses the FFR trigger through the command path — POI meter, plant controller (PPC), energy storage controller (ESC), inverter — to delivered active power. Each hop adds latency; the example delivers full power well inside the 0.25 s ERCOT limit, leaving margin.
Why it matters for BESS
Fast frequency response is a revenue-bearing ancillary service, but only if the full detection-to-delivery chain fits inside the market window. Mapping the latency budget across the command path is how engineers prove a plant can qualify — and where they find the milliseconds when it cannot.
Frequently asked
- What is Fast Frequency Response (FFR)?
- FFR is an ancillary service in which a resource injects active power within a fraction of a second of a frequency deviation to arrest decline — far faster than traditional primary frequency response. ERCOT requires delivery within 0.25 seconds.
- Why is BESS well suited to FFR?
- Batteries and inverters can move from zero to full power in tens of milliseconds, so the binding constraint is the measurement and command chain, not the hardware — which is exactly what this timeline makes visible.