Main grid transmission reliability rate remained good in 2024
In 2024, the transmission reliability rate of the main grid managed by Fingrid remained at a good level but weakened compared to the peak levels of previous years. The effect of a single disturbance to last year's indicators was exceptionally large.
The main grid transmission reliability rate indicates the amount of energy transmitted for consumption in the main grid in relation to the total energy available for transmission.
Key figures for the main grid in 2024. The averages for the preceding five years are given in parentheses.
- The transmission reliability rate in the main grid was 99.9995% (99.9999%).
- The fall of a tower on a 110 kV line Kolsi-Forssa on July 29, 2024, caused 209 MWh of electricity not being delivered. Without the disturbance, the transmission reliability rate would have been 99.99978% which is close to an average level.
- The volume of electrical energy not transmitted for consumption because of disturbances was 374 MWh (71 MWh).
- The number of electricity supply interruptions (≥ 30 seconds) caused by disturbances was 0.10 per connection point (0.13).
- Disturbances caused an average 7.0 minutes (2.2 minutes) interruptions at connection points.
- The volume of energy not received from power plants was 115 MWh (298 MWh).
- The System Minute (SM) was 1.50 min (0.30 min).
- The Average Interruption Time (AIT) was 2.64 min (0.53 min).
- The imputed economic detriment that disturbance interruptions caused to consumer customers was EUR 4.7 (2.2) million.
The quality of frequency in the Nordic synchronous area remained good. In 2024, the frequency was outside the normal range (49.9–50.1 Hz) for approximately 10,330 minutes. The upper limit set in the European network code is 15,000 minutes, and the Nordic target is 10,000 minutes.
Further information is available on our website under Supply security of electricity - Fingrid
The website also provides annual fault statistics for the Nordic and Baltic AC grid and fault and availability information for the cross-border DC connections.
Further information:
Markku Piironen, Specialist, Fingrid Oyj,
Email addresses firstname.lastname@fingrid.fi