Latvia - Estonia third interconnection

Estonia – Latvia third power transmission network interconnection is an important future infrastructure project for the Baltic Sea region that will increase the security of power supply in the region, ensure effective operation of the energy market in the Baltics and increase the competitiveness of producers both within the Baltic countries and the Nordic countries.

Latvian transmission system operator JSC Augstsprieguma tīkls is responsible for the implementation of the Estonia – Latvia 3rd interconnection project in the territory of Latvia.


Project events


All construction works of the JSC Augstsprieguma tīkls (AST) development project "Estonia-Latvia third 330 kV…


The State Office of Construction Control has commissioned the newly built 330 kV electricity transmission line from…

Latvia - Estonia 3rd interconnection

Under the framework of the project, it is planned to construct a 330 kV high voltage power transmission line with a total length in the territories of Latvia and Estonia of approximately 200 km between the substations Kilingi-Nōmme in Estonia and Riga CHP-2 in Latvia. The new power transmission line in Latvia and Estonia will mainly be built along the already existing power transmission line routes.

The project is a serious step towards increasing transfer cross-border capacity and elimination of overload in the Estonia-Latvia transmission cross-section - the estimated transfer capacity increase is 500/600 MW in both directions.

The project is to be completed by 2020 and it is included in the Latvian, Estonian and European transmission system development documents. The costs of the project in the territory of Latvia are estimated at around  EUR 100 million.

The costs of Estonia-Latvia third interconnection will be partially covered from the funds of  Connecting Europe Facility, while the project environmental impact assessment in the territory of Latvia was implemented with co-funding from the European Union TEN-E.

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Work progress plan

It is planned to complete the project Estonia-Latvia 3rd Interconnection in 2020.

Application submission to the Environmental State Bureu for environmental impact assessment and right of way study
With co-funding from the European Union TEN-E, the route research and environmental impact assessment (EIA) process was started in the Latvian territory while the Estonian side funded such works in its territory itself.
On 1 August 2014, the Estonian TSO Elering AS, Latvian TSO JSC Augstsprieguma tīkls and the owner of the Latvian transmission network JSC Latvijas Elektriskie tīkli (LET) signed the letter of intent on the principles of cooperation and areas of responsibility within the implementation of the project.
In November 2014 European co-funding in the amount of 65% was granted to the construction of the Estonia-Latvia 3rd interconnection from the funds of the Connecting Europe Facility. It is planned to complete the project in 2020

Public discussion with all municipalities and landowners involved
Route approved

On 24 August 2016, the Cabinet of Ministers has approved the results of EIA of the project in the territory of Latvia and has granted the status of national importance to the project.

Tender announced



On 1st December 2017 the right to sign the contract was obtained by the association of entities “SIA “ELKO”, SA “SELPOL” un AS “Leonhard Weiss Energy”” (EE-LV Interconnection constructors community).

Signing of contracts for designing and building
the electric transmission line.
Design, topographic, geological activities

Individual communication with landowners regarding the conclusion of encumbrance and compensation agreements
Completion of the construction and clean-up of the areas affected 
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Leaflet about the project
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Technical background of the project

The Estonia-Latvia cross-border cross-section is the most loaded section in the power transmission network of the Baltic countries. The third Estonia-Latvia interconnection will enable elimination of overloads of the existing transmission network in the cross-section between Estonia and Latvia and increasing of the transfer capacity available to the electricity market.

Current transfer capacity of the Estonia-Latvia cross-section, especially in summer and under the power transmission network repair modes, is not sufficient to provide for the entire electricity trade amount demanded in the Baltics. Besides, to eliminate technical limitations, the Estonian transmission system operator needs to reconstruct the already existing 330 kV lines, while during reconstruction the transfer capacity in the Estonia-Latvia cross-section available to the electricity market will be close to zero. Therefore, the above project is an important step to increase the cross-border transfer capacity and to eliminate overloads in the Estonia-Latvia cross-section as well as a precondition for effective cross-border electricity trade and development of a competitive electricity market. It is essential that after implementation of the Latvia - Estonia 3rd interconnection project and other interconnections, the strengthened power system of the Baltic countries and its connections to the Nordic and Central European power networks will serve as a safe and stable alternative route for the import or export of electricity from Nordic countries to Central Europe.

Increasing reliability of the electricity supply

The project will significantly increase reliability of the electricity supply in the cross-section between Estonia and Latvia as well as in power systems of both countries. The two existing 330 kV interconnection lines are geographically situated within a single narrow belt and are connected in the Territory of Latvia to a single 330 kV substation in Valmiera. The planned third interconnection will use a different corridor and will connect two other substations in the Latvian and Estonian transmission networks. The project has a positive impact on the voltage levels in the network and dynamic stability of power stations in the network contingency situations in the region of Baltic power systems, where a probable loss of large generation units in Latvian or Lithuanian power systems in the event of emergency may impact the security of the electricity supply in the entire Baltic region. In order to prevent this, the transmission operators are currently forced to reduce the transfer capacity available for the electricity market. If after 2025 the power systems of Baltic countries will start synchronous operation with power systems of Continental Europe, this project will serve as a precondition for maintaining safe and stable operation of power systems of the Baltic countries.

Establishment of an effective and reliable transit corridor

The project will provide for the effective power transit corridor between Baltic and Nordic country power systems from the North via the Estonian – Finnish interconnections Estlink 1 and Estlink 2 to the South via NordBalt (Lithuania – Sweden) and LitPol link (Lithuania – Poland) interconnections.

Connecting new generation capacities to the power transmission network

The interconnection is creating possibilities for connecting new generating units utilising renewable energy resources to the power transmission system, thus facilitating achievement of the goals proposed by the European Commission energy policy for the period until 2020 and 2030, including more optimal usage of existing generation capacities and reducing the volume of CO2 emissions.

The best option for implementation of the project

The Latvian transmission system operator (TSO), JSC Augstsprieguma tīkls, and the Estonian TSO, Elering AS, having analysed technical and economical parameters of the interconnection options, decided that the best option for the Estonia-Latvia third interconnection is the route between the substations Kilingi-Nōmme in Estonia and Riga CHP-2 in Latvia with a total length in the territories of Latvia and Estonia of approximately 200 km. The new 330 kV power transmission line in Latvia and Estonia will mainly be built along the already existing power transmission line routes. This project option has smaller construction costs and, which is substantial, the largest increase of transfer capacity, i.e. 500/600 MW in both directions. An additional benefit is improved security of 110 kV transmission network in the section Riga - Rūjiena.

The costs of the project in the territory of Latvia are estimated at around EUR 100 million.


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Environmental Impact Assessment

In September 2012, JSC Latvijas elektriskie tīkli, as the owner of assets of the Latvian transmission system and a body responsible for research of the route and environmental impact assessment, submitted the application to the State Environmental Bureau regarding performance of the environmental impact assessment and research of the route of the Estonia-Latvia 3rd power transmission network interconnection.

The application for the envisaged activities can be found here.

During the period between January and April 2013, the representatives of JSC Latvijas elektriskie tīkli and JSC Augstsprieguma tīkls participated in the initial public discussions with the involved municipalities and land owners regarding the possible high voltage power transmission line route options in the territory of Latvia. After evaluating the results of the initial public discussions, the State Environmental Bureau (SEB) developed, and on 4 July 2013 approved, the programme for carrying out environmental impact assessment (EIA) for the third Estonia-Latvia power transmission network interconnection between Sindi (Kilingi-Nōmme) substation in Estonia and Salaspils (Riga CHP-2) substation in Latvia. The programme approved by the SEB can be found here.

Pursuant to the Law On Environmental Impact Assessment and the environmental impact assessment programme approved by the State Environmental Bureau (SEB) on 4 July 2013, LLC Eiroprojekts was selected as the winner of the procurement procedure that will develop the final EIA report. The process of EIA and route research was started in April 2014.

After the research of all available alternatives, a draft final EIA report was developed and public discussion of it with all involved municipalities and land owners took place in November and December 2015 by offering already specific solutions and taking into account all opinions of or objections from residents and municipality representatives. Documents of public discussions may be found here.

In light of the compromises made during public discussions, in February 2016 LLC Eiroprojekts submitted the final EIA report to the State Environmental Bureau (SEB) for examination and making a decision; a particularised final report was submitted in April 2016The SEB provided its conclusion regarding the final report on 10 June 2016, while on 24 August 2016 the final EIA report was approved by the Cabinet of Ministers of the Republic of LatviaOn 24 August 2016 the Cabinet of Ministers of the Republic of Latvia granted the Estonia - Latvia third interconnection project the status of national importance.

More detailed information about the progress of the EIA development and the decisions made may be found on the SEB website.

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