29.6.2021 16:08
Current News

High-voltage direct current links connecting Finland to Sweden and Estonia again among the most reliable in the Nordic countries

The high-voltage direct current (HVDC) links connecting the Finnish grid to Sweden and Estonia were among the very best in the Nordic countries in terms of technical availability in 2020. The connections ensure the security of transmission to consumption in Finland.

Statistics on Nordic and Baltic links for 2020 have been published on Fingrid's website. The statistics provide information on the transmission, availability and outages of direct current connections between different countries.

Connections in efficient use

The electricity market utilised the most FI-SE3 connection between Finland and Sweden, 85% of the total capacity i.e. 8.9 TWh. The transmission was almost entirely import to Finland.

The FI-EE connection between Finland and Estonia was also among the best at 75% of the total capacity, ie 6.6 terawatt hours. The transmission was mainly export to Estonia. 

The utilisation rate of the Fenno-Skan 1 link was again by far the highest of the HVDC connections, as high as 97% of the technical capacity. The next best were EstLink 2 (85%) and Fenno-Skan 2 link (78%). The utilization rate of the EstLink 1 link in 2020 was 57%.

EstLink 1 connection is regularly used also to support the frequency of the Nordic power system. Fingrid purchases part of the frequency containment reserves from Estonian HVDC links. In addition, EstLink 1 converter stations are utilised as part of the voltage regulation and reactive power management of the Finnish and Estonian main grids. This activity will help the electricity transmission of both countries to operate as securely as possible.

Both in 2019 and 2020, the technical capacity of Finnish links was out of service due to disturbances and maintenance work on average only 1.8% of the hours throughout the year, i.e. for about 160 hours.

In the Nordic and Baltic countries, all four Fingrid's HVDC connections (Fenno-Skan 1, Fenno-Skan 2, EstLink 1 and EstLink 2) were among the five best HVDC connections in terms of technical availability.

Further information:

Specialist Markku Piironen, Fingrid, tel. + 358 30 395 4172, markku.piironen (at) fingrid.fi

Nordic and Baltic HVDC interconnectors statistics 2020 >

Definitions:

Utilization rate % = Transmission (TWh) / The maximum energy (TWh) that can be physically received through the HVDC link to the converter station excluding all HVDC link losses.

Technical availability % = (Transmission TWh + Technical capacity not used TWh) /  The maximum energy (TWh).

Unavailability of technical capacity due to disturbances and maintenance = Disturbance outages + unplanned maintenance + planned maintenance