Synchronisation with Continental Europe
Current situation: Estonia, together with Latvia and Lithuania, disconnected its power system from the Russian frequency area on 8 February 2025 and, following an island mode test, connected it to the Continental Europe Synchronous Area on 9 February.
Until then, the Baltic States’ power system was part of Russia’s interconnected power system, which posed a geopolitical and energy security risk. This is because Russia controlled one of the most important parameters of our power system – frequency – and thus the eastern neighbour had the ability to influence the operation of the power system in the Baltic States.
Synchronisation Information Day 28 November 2024
Why we synchronised?
First, the transition to synchronous operation with the Continental Europe Synchronous Area mitigated the risk that dependence on the Russian energy system and frequency area could be used against us. Secondly, the Baltic States are politically and socio-economically part of Western Europe, so it is entirely logical that the power system is also part of the Continental Europe Synchronous Area. This have reduced the risks associated with system management and improve the energy security of Estonian people and companies.
In addition to energy security, Estonia’s greater connectivity also improves the international competitiveness of its economy. During synchronisation, new markets and products emerged alongside existing electricity markets, increasing the opportunities for local electricity producers to sell electricity.
How did synchronisation take place?
To mitigate risks and expand the market, steps were taken over the years to disconnect the power systems of Estonia, Latvia, and Lithuania from Russia’s and connect them to the Continental European electricity network and the corresponding frequency area by the beginning of 2025 at the latest. Synchronisation was a joint and extremely high-priority effort undertaken by the three Baltic States and Poland.
For synchronisation, the Baltic States reinforced their electricity networks and interconnections. Elering reconstructed the powerful 330-kilovolt power lines that originated in the Narva region and extended to Latvia near Valga. Similar reinforcements were also carried out in the power systems of Latvia and Lithuania.
To ensure frequency stability, synchronous compensators that added inertia to the system were built in all Baltic States, and the power system, IT systems, and control systems for existing direct current connections were upgraded.
In addition to the new infrastructure and systems, synchronisation improved the interoperability of the control centres of the Baltic States and provided additional expertise for the independent management of the electricity network.
Project financing
Synchronisation cost the Baltic States and Poland a total of approximately 1,6 billion euros, of which Estonia´s share was 298 million euros. Investments were divided into three rounds and, due to the high priority assigned by the European Commission, the projects were financed up to 75% through the Connecting Europe Facility (CEF). The remaining 25% of the required investments was covered by congestion charges in Estonia.
The total investment volume of the first financing round in the Baltic States was approximately 430 million euros. In Estonia, the first round included the reconstruction of domestic electricity networks and the construction of one synchronous compensator. Similar improvements to domestic network connections were carried out in Latvia and Lithuania, where synchronous compensators were also built.
The volume of the second round of investments in the Baltic States and Poland was approximately 700 million euros and included the construction of two synchronous compensators in Estonia. The investments financed the construction of synchronous compensators in the other Baltic States, as well as the construction of a direct current connection between Lithuania and Poland and the necessary network reinforcements.
The total investment volume of the third round in the Baltic States and Poland was 230 million euros. In Estonia, the third-round investments included upgrades to the control centre’s IT, control, and monitoring systems; upgrades to the management and control systems of the EstLink 1 and EstLink 2 submarine cables; and improvements to the operational continuity of substations. In the other Baltic States and Poland, third-round investments included the reconstruction of high-voltage lines, further development of substations, construction of battery-based energy storage systems in Latvia, and upgrades to IT systems.
In Estonia, a total of approximately 30 investment projects were financed as part of the synchronisation process.
See how the project was implemented over the years:
Synchronisation in brief:
Benefits for market participants
For electricity producers and traders, synchronisation opened up a larger and more flexible market, allowing them to offer new types of energy market products and services and expanding their export potential. New markets emerged alongside existing ones, increasing opportunities for electricity producers to sell electricity. Since electricity trade with Russia and Belarus had ended in 2022, access to new markets became crucial for market participants.
System operators introduced new products to the electricity market, giving market participants the opportunity to provide new services. These services included, for example, frequency maintenance reserve services and automatic frequency restoration reserves. System operators involved market participants in the development and introduction of these new products to ensure they met their capabilities and expectations.
Benefits for the consumer
Synchronisation primarily ensures better security of supply for consumers, but also a sense of security that Estonia itself, not Russia, has control over the energy system. In addition, European Union investments made it possible to reconstruct ageing high-voltage lines without requiring additional funding that would have led to an increase in network fees. The transition from one frequency area to another took place without any noticeable impact on end users, while the quality and continuity of network services improved.
Environmental impact
Estonia has joined the goal of carbon neutrality, which aims to slow down global climate change. It is therefore unthinkable to invest in renewable energy in our country and at the same time consume electricity from third countries with unknown environmental impacts. Carbon emissions cannot be reduced if they are released into the air across borders. Synchronisation eliminated the risk of potential carbon leakage and improves the ability to generate electricity from renewable sources.
What happens if the Baltic States become electrically islanded?
The Baltic States are connected to the Continental European electricity system through the 500 MW LitPol Link interconnection between Lithuania and Poland. In addition, a new 700 MW direct current interconnection, Harmony Link, is planned between Lithuania and Poland, with completion scheduled for 2030. The Baltic electricity systems have been prepared for situations in which the connection to the Continental European system is temporarily interrupted and the region must operate independently, as an electrical island. To address such scenarios, the Baltic transmission system operators, including Elering, have agreed on clear action plans and cooperation procedures to ensure the stable operation of the electricity system even in emergency situations.The capability to manage such situations has been thoroughly tested, including prior to synchronisation with the Continental European frequency area, and all tests have been successful. Thanks to these preparations and close cross-border cooperation, the reliability of electricity supply can be maintained, supporting regional security and the functioning of the economy even under challenging circumstances.
Mitigation of risks
The probability and impact of possible risks materialising are continuously assessed at Elering in order to prevent and mitigate their negative impact on the activities necessary for synchronisation.
Project overview
Synchronous compensators
Synchronous compensators
Elering built synchronous compensators at the Püssi, Kiisa and Viru substations and they are used for frequency control.
According to studies and electricity market changes, the Baltic power system does not have the necessary inertia after disconnection from the Russian frequency area to ensure frequency stability and the required rate of change of frequency. Because of this, we built three synchronous compensators in Estonia, which help to control frequency.
In the Estonian context, the introduction of synchronous compensators means that the need to keep Narva power plant modules operating outside the market to ensure frequency is reduced, which entails significant costs.
Elering built synchronous compensators at the Püssi, Kiisa and Viru substations. The function of synchronous compensators is to add inertia to the system to slow down the frequency change and enable the implementation of subsequent measures in the frequency control process, for example in the event of emergencies. The synchronous compensators to be built have high reliability and, in addition to inertia, support the network with short-circuit power and reactive energy compensation.
A total of nine synchronous compensators will be built in the Baltic States. In Estonia, synchronous compensators were built by the Estonian branch of Siemens Energy Oy and Siemens Energy Global GmbH & Co. KG. All synchronous compensators manufactured in Estonia are identical in design and operating principles, which simplifies maintenance and allows for the construction of equipment in the shortest possible time frame.
Püssi synchronous compensator station
The first synchronous compensator station was connected to the network in May 2023. Of the nine synchronous compensators to be built in the Baltics, Püssi was the first to be completed, thereby helping to ensure frequency stability.
Kiisa synchronous compensator stationnkompensaatorjaam
The second synchronous compensator station in Kiisa was completed in January 2024.
Viru synchronous compensator station
The third and final synchronous compensator station in Estonia was completed at the Viru substation in June 2024.
TIMELINE:
|
Activity |
Deadline |
|---|---|
|
Start of the procurement process |
18.05.2020 |
|
Entry into a contract |
16.12.2020 |
|
Start of work at Püssi station |
01.01.2021 |
|
Start of work at Kiisa station |
01.05.2022 |
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Start of work at Viru station |
01.05.2022 |
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Completion of work at Püssi station |
01.05.2023 |
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Completion of work at Kiisa station |
01.01.2024 |
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Completion of work at Viru station |
01.06.2024 |
Transport and installation of the Viru synchronous compensator generator, September 2023:nkompensaatori generaatori transport ja paigaldus, september 2023:
Transport of the Viru synchronous compensator transformer, September 2023:
Preparing the Kiisa synchronous compensator generator for installation, May 2023:
Transport of the Kiisa synchronous compensator generator from the Port of Paldiski to Kiisa, May 2023:
Arrival of the basic equipment of the Kiisa synchronous compensator in April 2023:
Arrival of the equipment of the Püssi synchronous compensator in June 2022:
Read more:
High-voltage lines
High-voltage lines
Elering reconstructed old overhead lines and line corridors to increase the capacity of power lines.
Separation from the Russian power system means that the option to direct some power flows through the Russian power system disappears, meaning that all the power transmitted between Estonia and Latvia will be transferred only to the lines between Estonia and Latvia. Reconstructing the lines will maintain capacity at the existing level and help to avoid restrictions in the north-south transit. In summary, after synchronisation, we will have a new network that is at least as strong as before and we will completely eliminate the influence of third countries on inter-market trading in the Baltic States.
Elering chose reconstruction instead of building new lines to ensure timely completion of projects, thereby reducing potential costs. When reconstructing lines, it is important to keep in mind that sufficient transmission capacity is guaranteed in all situations in the event that some lines fail (n-1 situation), which is why it is not possible to reconstruct all lines simultaneously.
Lines L300/L301 together with lines L353/L354 form a parallel line corridor between Estonia and Latvia. The reconstruction of the lines was necessary to strengthen the connections between the Estonian electricity system and the rest of the power system, to create the prerequisites for synchronous operation with the European power system. The lines play an important role in allowing manufacturers to enter the Estonian market at a lower price. Since the 330 kV lines in Estonia were built in the 1950s and 1960s, their lifespan was coming to an end and the need for renovation was great.
Reconstruction of the Baltic-Tartu (L300) 330 kV overhead line
The reconstruction of the Baltic-Tartu 330 kV overhead line began in 2020. The line was completed and energised in February 2023.
TIMELINE:
|
Activity |
Deadline |
|---|---|
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Start of the procurement process |
02.01.2019 |
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Entry into a contract |
30.11.2020 |
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Start of construction work |
12.04.2021 |
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Completion of construction work |
01.03.2023 |
Dismantling work of the L300 Baltic-Tartu line:
Erection of a new tower in Iisaku, June 2022:
Reconstruction of the Tartu-Valmiera (L301) 330 kV overhead line
The reconstruction of the Tartu-Valmiera line began in autumn 2021. The line was energised together with Latvian partners in May 2023.
TIMELINE
|
Activity |
Deadline |
|---|---|
|
Start of the procurement process |
02.01.2019 |
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Entry into a contract |
30.11.2020 |
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Start of construction work |
20.09.2021 |
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Completion of construction work |
01.06.2023 |
Reconstruction of the Baltic-Tartu and Tartu-Valmiera 330 kV overhead lines, 2021–2023:
Reconstruction of the Viru-Tsirguliina (L353) 330 kV overhead line
Similar to the Baltic-Tartu-Valmiera line, the Viru-Tsirguliina-Valmiera 330 kV overhead line was also reconstructed. Even before the start of synchronisation operations, the 11.48-kilometer section of the Tsirguliina-Valmiera (L354) line located on Estonian territory was reconstructed in 2015. During the reconstruction, the cable was replaced and the clearance was adjusted.
The reconstruction of Viru-Tsirguliina (L353) was completed in November 2024.
Elering energised the important Viru-Tsirguliina power connection for synchronisation | Elering
TIMELINE:
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Activity |
Deadline |
|---|---|
|
Start of the procurement process |
01.08.2020 |
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Entry into a contract |
02.06.2021 |
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Start of construction work |
01.06.2023 |
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Completion of construction work |
31.12.2024 |
Upgrades to the control systems of EstLink 1 and EstLink 2
Upgrades to the control systems of EstLink 1 and EstLink 2
The EstLink 1 and EstLink 2 submarine cables are some of the most important connections between the Baltic States and the Nordic countries, which provide support for frequency regulation for our power system where necessary.
Due to the requirements and functionalities associated with synchronisation, it is necessary to upgrade the command and control systems of the converter stations of both submarine cables located on the mainland.
The depreciated hardware of the EstLink1 control systems will be replaced, and the control and protection system of the entire converter will be updated and brought in line with modern requirements and needs.
TIMELINE OF ESTLINK 1:
|
Activity |
Deadline |
|---|---|
|
Start of the procurement process |
30.07.2022 |
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Entry into a contract |
21.11.2023 |
|
Completion of work |
30.09.2027 |
TIMELINE OF ESTLINK 2:
|
Activity |
Deadline |
|---|---|
|
Start of the procurement process |
01.03.2023 |
|
Expected completion of work |
31.12.2025 |
Upgrades to IT, data communications and control systems
Upgrades to IT, data communications and control systems
The projects and investments necessary for synchronisation include not only infrastructure projects, but also require the development of the IT and communication capabilities of the electricity control system.
As part of this, the power system planning and control systems (SCADA/EMS) will be updated, which will make it possible to plan, monitor and control changes in the power system remotely. As a result of the update, the control centre’s ability to assess and control the power system in real time will be improved.
It is also important that real-time metering data and data exchange for monitoring the stability of the power system and frequency control are of high quality, reliable and guaranteed consistently. To this end, data communication and monitoring systems at critical substations will be replaced with newer and more reliable equipment that ensures continuous transmission of data related to voltage, current, and frequency.
Furthermore, various generation and consumption forecasting systems will be updated, and new balance administration software and outage planning software will be procured and implemented.
TIMELINE:
|
Activity |
Deadline |
|---|---|
|
Start of the procurement process |
01.12.2021 |
|
Entry into a contract |
01.02.2022 |
|
Start of development work |
01.02.2022 |
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Completion of development work |
01.12.2025 |