System Stress: GB Grid Frequency
Grid frequency measured every 15 seconds, published by Elexon in roughly 2-minute batches. The newest reading is typically 1–2 minutes behind the current moment; this page ingests every 5 minutes and refetches every 60 seconds.
Latest reading
No readings available yet.
Last 24 hours — 5-minute average with min–max range
Not enough readings in the last 24 hours to draw the chart yet.
Excursion event log — permanent ledger
0 events recorded
| Started (UTC) | Duration | Direction | Extreme (Hz) | Band reached | Data gaps | |
|---|---|---|---|---|---|---|
| No events match the current filters. | ||||||
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Methodology & data handling
- Source: Elexon BMRS Insights API,
GET /system/frequency(dataset FREQ). Frequency is measured every 15 seconds, published by Elexon in roughly 2-minute batches; the newest reading is typically 1–2 minutes behind the current moment. - Resolution & query limits: one reading every 15 seconds; the source API serves at most 7 days per request (verified against the live endpoint).
- Validity filter: the source feed occasionally publishes placeholder readings outside 45–55 Hz. These rows are stored as published but excluded from charts, aggregates, and event detection; the missing span is recorded as a data gap — never interpolated.
- Bands: an event opens when readings leave the operational band (49.80–50.20 Hz) and closes after readings hold inside it for 60 seconds; “statutory band” marks events whose extreme fell outside 49.50–50.50 Hz.
- Retention: raw 15-second readings are kept for 90 days; daily minimum / maximum / average figures and the event ledger (with per-event traces) are permanent.