2016-04-15
Cause of NordBalt disruption being determined
On 14 April, power transmission via the NordBalt power interconnection between Lithuania and Sweden was disrupted. The reasons behind the interconnection failure are currently being determined; repair will begin once the cause and location are established. As soon as the 700-megawatt interconnection shut down and the amount of electricity being imported into Lithuania decreased, Litgrid activated the necessary reserves – 300 MW from Poland and 400 MW from the Kruonis Pumped Storage Plant. Consumers did not experience any inconvenience.
“Spring – when electricity consumption decreases and supply is high due to spring flooding – is a good time to test interconnections, and this ensures electrical supply to the market,” said Daivis Virbickas, CEO at Lithuanian electricity transmission system operator Litgrid.
Latvian hydroelectric power plants traditionally produce particularly high amounts of electricity in spring, and this year the water level is almost twice that of the multi-annual average. However, the Kaliningrad thermal power plant is being closed for planned maintenance from 15 April.
The NordBalt trial operations started in February, and the transmitted electricity has since been traded on the market. During the test phase, it is normal for the system to shut down more frequently; this will occur less often in the future.
The amount of time it takes to eliminate high voltage direct current interconnection failures depends on the cause and location of the problem. Repairing submarine and underground cable failures can take anywhere from several days to several months.
According to data from ENTSO-E, the European Network of Transmission System Operators for Electricity, each of the 14 high voltage direct current interconnections operating in Northern Europe shut down an average of 9.8 times in 2013; half of the disruptions were caused by equipment failures.