Welcome to the report of the PQopen measurement network for 2026-08.
News of PQopen Network
New Location in Baltic: LV/Riga. This very interesting measurement point makes the dynamics visible in combination with power exchange with Nordic area.
Summary
Evaluated is the 1s-mean value of the mains frequency measured in CH/Solothurn.
| Statistics | Value and occurrence |
|---|---|
| MIN | 49.8868 Hz (2026-08-22 22:00:53 CEST) |
| 1% Percentile | 49.9464 Hz |
| MEAN | 50.0002 Hz |
| 99% Percentile | 50.0520 Hz |
| MAX | 50.1356 Hz (2026-08-23 16:16:52 CEST) |
Daily Mean

Rate of Change of Frequency (ROCOF)

Frequency Spread

Other Abnormalities
Deviations of frequency below and above the ±100 mHz band, with the change to the previous month in brackets:
| < 49.9 Hz | > 50.1 Hz | |
|---|---|---|
| Count of threshold crossings | 10 (+3) | 28 (+10) |
| Number of seconds below/above | 131 (+83) | 484 (+370) |
Events
List of all detected events
| Timestamp (UTC) | Timestamp (CET) | Text | Category |
|---|---|---|---|
| 2026-08-29 16:57:19 | 2026-08-29 18:57:19 | NL: TTB-TTG/380/DIELE-MEEDEN/WS | Transmission Failure |
| 2026-08-26 08:28:14 | 2026-08-26 10:28:14 | NO: SIMA G1 HYDRO (315 MW) | Generation Outage |
| 2026-08-26 04:31:51 | 2026-08-26 06:31:51 | NO: SIMA G1 HYDRO (315 MW) | Generation Outage |
| 2026-08-25 20:28:42 | 2026-08-25 22:28:42 | NO: SIMA G1 HYDRO (315 MW) | Generation Outage |
| 2026-08-25 07:08:50 | 2026-08-25 09:08:50 | NO: SIMA G1 HYDRO (315MW) | Generation Outage |
| 2026-08-24 15:49:13 | 2026-08-24 17:49:13 | France: GOLFECH 2 (1310MW) | Generation Outage |
| 2026-08-22 18:18:59 | 2026-08-22 20:18:59 | LV: start of series of multiple voltage dips | Voltage Dip |
| 2026-08-21 09:13:12 | 2026-08-21 11:13:12 | Eastern Germany | Frequency Swing |
| 2026-08-20 12:17:09 | 2026-08-20 14:17:09 | Southern-East Europe | Frequency Swing |
| 2026-08-19 10:17:11 | 2026-08-19 12:17:11 | IFA-2: Tourbe-Dædalus (1014 MW) | Transmission Outage |
| 2026-08-19 02:57:46 | 2026-08-19 04:57:46 | Estlink? | Transmission Failure |
| 2026-08-18 12:43:07 | 2026-08-18 14:43:07 | Estlink? | Transmission Failure |
| 2026-08-18 12:38:54 | 2026-08-18 14:38:54 | Southern-East Europe | Generation Outage |
| 2026-08-18 06:33:34 | 2026-08-18 08:33:34 | France: TRICASTIN 3 (915 MW) | Generation Outage |
| 2026-08-17 12:20:39 | 2026-08-17 14:20:39 | Southern-East Europe | Frequency Swing |
| 2026-08-16 06:10:00 | 2026-08-16 08:10:00 | France: PALUEL 4 (1330 MW) | Generation Outage |
| 2026-08-15 03:30:02 | 2026-08-15 05:30:02 | Failure in Northern Germany, possible trip of transmission line | Frequency Swing |
| 2026-08-14 19:17:44 | 2026-08-14 21:17:44 | Spain | Voltage Dip |
| 2026-08-13 13:35:59 | 2026-08-13 15:35:59 | Southern-East Europe | Frequency Swing |
| 2026-08-13 06:00:24 | 2026-08-13 08:00:24 | France: CRUAS 2 (915MW) | Generation Outage |
| 2026-08-11 22:01:47 | 2026-08-12 00:01:47 | TR/Istanbul: UPS Operation | Local Power Outage |
| 2026-08-11 04:20:07 | 2026-08-11 06:20:07 | PL: Opole B6 (833MW) | Generation Outage |
| 2026-08-09 19:17:20 | 2026-08-09 21:17:20 | TR/Istanbul: UPS Operation | Local Power Outage |
| 2026-08-08 14:56:38 | 2026-08-08 16:56:38 | NL: Onyx Power 731MW in Rotterdam | Generation Outage |
| 2026-08-08 14:06:23 | 2026-08-08 16:06:23 | Southern-East Europe | Frequency Swing |
| 2026-08-07 01:56:49 | 2026-08-07 03:56:49 | Northern Germany; Transmission Failure between Nordic and CE | Frequency Swing |
| 2026-08-04 10:39:49 | 2026-08-04 12:39:49 | Southern-East Europe | Frequency Swing |
| 2026-08-03 13:24:29 | 2026-08-03 15:24:29 | Disconnection of Offshore Windpark? | Frequency Swing |
| 2026-08-02 12:01:45 | 2026-08-02 14:01:45 | NL/Amersfoort Oscillation Record: 250mHz p-p / 10V p-p | Oscillation |
| 2026-08-02 07:49:24 | 2026-08-02 09:49:24 | Sourthern-East Europe | Frequency Swing |
| 2026-08-01 21:40:30 | 2026-08-01 23:40:30 | Failure in Nordic/CE Link | Transmission Outage |
| 2026-08-01 14:54:09 | 2026-08-01 16:54:09 | Spain (details unknown) | Generation Outage |
Event Metrics
Automatically derived from the event plots: frequency nadir/zenith (10-cycle moving average), peak ROCOF (500 ms window per ENTSO-E convention), settling time (time until every location stays within ±10 mHz of 50 Hz) and the location with the highest peak ROCOF.
| Timestamp (UTC) | Event | Min in Hz | Max in Hz | Peak ROCOF in mHz/s | Settling in s | Peak location |
|---|---|---|---|---|---|---|
| 2026-08-29 16:57:19 | NL: TTB-TTG/380/DIELE-MEEDEN/WS | 49.9590 | 50.0260 | 371.8 | 7.9 | DE/Essen |
| 2026-08-26 08:28:14 | NO: SIMA G1 HYDRO (315 MW) | 49.9492 | 50.0409 | 21.4 | 7.9 | FI/Helsinki |
| 2026-08-26 04:31:51 | NO: SIMA G1 HYDRO (315 MW) | 49.9316 | 50.0024 | 36.8 | 7.9 | SE/Malmoe |
| 2026-08-25 20:28:42 | NO: SIMA G1 HYDRO (315 MW) | 49.9055 | 49.9998 | 48.0 | 7.9 | SE/Malmoe |
| 2026-08-25 07:08:50 | NO: SIMA G1 HYDRO (315MW) | 49.9329 | 50.0305 | 45.8 | 7.9 | SE/Malmoe |
| 2026-08-24 15:49:13 | France: GOLFECH 2 (1310MW) | 49.9354 | 50.0049 | 98.9 | 7.9 | ES/Pamplona |
| 2026-08-22 18:18:59 | LV: start of series of multiple voltage dips | 49.9007 | 50.0994 | 1015.2 | 7.9 | LV/Riga |
| 2026-08-21 09:13:12 | Eastern Germany | 49.9999 | 50.0488 | 132.2 | 7.9 | CH/Solothurn |
| 2026-08-20 12:17:09 | Southern-East Europe | 49.9435 | 50.0723 | 743.4 | 7.9 | ME/Podgorica |
| 2026-08-19 10:17:11 | IFA-2: Tourbe-Dædalus (1014 MW) | 49.9543 | 50.0131 | 77.9 | 6.2 | AT/Graz |
| 2026-08-19 02:57:46 | Estlink? | 49.9638 | 50.0710 | 1592.2 | 2.2 | FI/Helsinki |
| 2026-08-18 12:43:07 | Estlink? | 49.9727 | 50.1128 | 1023.6 | 4.5 | FI/Helsinki |
| 2026-08-18 12:38:54 | Southern-East Europe | 49.9307 | 49.9973 | 88.8 | 7.9 | AT/Graz |
| 2026-08-18 06:33:34 | France: TRICASTIN 3 (915 MW) | 49.9351 | 49.9800 | 74.7 | 7.9 | ES/Pamplona |
| 2026-08-17 12:20:39 | Southern-East Europe | 49.9335 | 49.9913 | 90.9 | 7.9 | ME/Podgorica |
| 2026-08-16 06:10:00 | France: PALUEL 4 (1330 MW) | 49.9542 | 50.0304 | 41.6 | 7.9 | TR/Istanbul |
| 2026-08-15 03:30:02 | Failure in Northern Germany, possible trip of transmission line | 49.9068 | 50.0427 | 503.9 | 7.2 | DE/Stade |
| 2026-08-14 19:17:44 | Spain | 50.0011 | 50.0455 | 372.8 | 7.9 | ES/Pamplona |
| 2026-08-13 13:35:59 | Southern-East Europe | 49.9485 | 50.0740 | 979.4 | 7.9 | ME/Podgorica |
| 2026-08-13 06:00:24 | France: CRUAS 2 (915MW) | 49.9894 | 50.0423 | 82.1 | 5.5 | DE/Essen |
| 2026-08-11 22:01:47 | TR/Istanbul: UPS Operation | 0.0000 | 49.9978 | 25595.8 | 7.9 | TR/Istanbul |
| 2026-08-11 04:20:07 | PL: Opole B6 (833MW) | 49.9688 | 50.0150 | 38.4 | 7.9 | ES/Pamplona |
| 2026-08-09 19:17:20 | TR/Istanbul: UPS Operation | 49.9767 | 50.0567 | 163.8 | 7.9 | TR/Istanbul |
| 2026-08-08 14:56:38 | NL: Onyx Power 731MW in Rotterdam | 49.9309 | 49.9958 | 97.9 | 7.9 | ES/Pamplona |
| 2026-08-08 14:06:23 | Southern-East Europe | 49.9528 | 50.0745 | 1136.8 | 7.9 | ME/Podgorica |
| 2026-08-07 01:56:49 | Northern Germany; Transmission Failure between Nordic and CE | 49.8838 | 50.0653 | 664.3 | 7.9 | DE/Stade |
| 2026-08-04 10:39:49 | Southern-East Europe | 49.9899 | 50.0215 | 86.0 | 7.6 | AT/Graz |
| 2026-08-03 13:24:29 | Disconnection of Offshore Windpark? | 49.8518 | 50.0819 | 473.3 | 7.9 | DE/Stade |
| 2026-08-02 12:01:45 | NL/Amersfoort Oscillation Record: 250mHz p-p / 10V p-p | 50.0347 | 50.0897 | 214.5 | 7.9 | NL/Eindhoven |
| 2026-08-02 07:49:24 | Sourthern-East Europe | 49.9676 | 50.0006 | 74.6 | 7.9 | ES/Pamplona |
| 2026-08-01 21:40:30 | Failure in Nordic/CE Link | 50.0082 | 50.0567 | 57.0 | 7.9 | ES/Pamplona |
| 2026-08-01 14:54:09 | Spain (details unknown) | 49.9522 | 50.0160 | 458.6 | 7.9 | ES/Pamplona |
Below, there are several graphs, each representing a detailed time series plot of cycle-by-cycle frequency as well as 10-cycle moving average, phase angle difference and voltage magnitude.
Central Europe Area





















Nordic Area






CE & Nordic Area




Yours,
Michael
