Estlinki

Estlinki, commonly known as Estlink, is a high-voltage direct current (HVDC) submarine electricity interconnector between Estonia and Finland. It consists of two parallel transmission links, Estlink-1 and Estlink-2, which run under the Gulf of Finland and connect the Estonian and Finnish power grids. The purpose is to enable cross-border electricity trade, improve grid reliability, and support the integration of renewable generation across the Baltic and Nordic regions.

The system uses HVDC technology with converter stations at each end to convert alternating current to direct current for the underwater cables and back to alternating current for the connected national grids. This arrangement allows efficient, long-distance transmission with lower losses and improved controllability compared with alternating-current links.

Estlink is a joint venture formed by the national transmission system operators of Finland and Estonia. The interconnectors are operated and maintained to ensure secure and efficient electricity exchange, market integration, and network stability across the two countries.

Impact and significance: By increasing cross-border capacity, Estlink supports electricity market integration within Nord Pool, enhances supply security, and enables more effective utilization of renewable energy resources in the region.

History: Estlink-1 entered service in the mid-2000s, followed by Estlink-2 in the following decade, together expanding the transmission capacity between Estonia and Finland.