2021-12-29
Litgrid and Siemens Energy Will Implement the Second Largest Synchronisation Project in Lithuania
On Wednesday, 29th December, the Lithuanian electricity transmission system operator Litgrid has signed a contract with Siemens Energy for implementation of three synchronous condensers in Lithuania by the end of 2024. This equipment is necessary for synchronous operation of the Baltic States with Continental European Synchronous Area (CESA).
The value of the contract for the design, manufacture and installation of synchronous condensers, that has been awarded to Siemens Energy after an international public tender, is 87.4 million euros (exclusive of VAT). The contractors will also have to provide after-sales service and supply of spare parts, which are necessary to ensure the continuous operation and maintenance of synchronous condensers.
“We finish this year by finalizing the main purchase of the second largest synchronisation project and signing a contract with an international partner. The new synchronous condensers will perform many functions that are important for the system reliability, that is, they will help us to control the frequency independently, integrate into the system more power plants that use renewable resources, conduct power trade with the neighbouring countries effectively. The electricity producers already operating in the country will also benefit from them”, says Rokas Masiulis, CEO of Litgrid.
"Following an order for synchronous condensers in Estonia, the order from Litgrid is the second we have received in the Baltic States for this technology”, said Volker Hild, Vice President Grid Stabilization at Siemens Energy. “We are proud that our state-of-the-art grid stabilization technology plays such an important role in the smooth synchronisation of the Baltic States' power grid with the continental European grid. The synchronous condensers will form the basis for a long-term reliable and affordable power supply in the Baltic States."
Benefits of synchronous condensers
Synchronous condensers are powerful and massive rotating motors, that are connected to the electric power transmission grid. They do not produce electricity. Their main task is to ensure required and stable frequency, which is one of the most important parameters of the electrical system.
“Currently, the Baltic States are part of the IPS / UPS synchronous system. Frequency here is regulated centrally by the Russian operator. However, after the synchronisation, the Baltic States will disconnect from the IPS / UPS system and they will have to ensure frequency stability on their own. This is why we need synchronous condensers”, says R. Masiulis.
The frequency of the electrical system in Europe is 50 Hz, and this is exactly the frequency that must be present in all system - from high voltage transmission lines to wires that reach every home. Normally, a stable frequency in the system is ensured by synchronously rotating generators of conventional power plants. However, not all electricity reaches our system from such facilities that operate synchronously and provide inertia. Part of electricity is imported through the direct current (DC) connections LitPol Link and NordBalt, and part of it is produced, for example, in wind turbines or solar power.
Importance for the integration of renewable sources
Such a system, in which a significant part of electricity is received via DC links or is produced from renewable sources (wind, solar power), can operate, but even a relatively minor disruption could result in a major change in frequency, which cannot be compensated by other generators operating in the system, because their inertia is simply insufficient.
“We will exercise control over this risk by connecting synchronous condensers to the grid. As the condensers rotate, they ensure sufficient inertia of the system even when a part of electricity reaches the system via DC interconnections or from asynchronous sources, such as wind/solar inverters. For example, the inertia of one new synchronous condenser, that we plan to install, will correspond to the total inertia of two working power units, 7th and 8th, at the Lithuania Power Plant” - says the CEO of Litgrid.
R. Masiulis emphasizes that synchronous condensers will also contribute to the development of renewable resources in Lithuania. Both wind turbines and solar power plants operate asynchronously. They supply electric power to the grid by means of inverters and so far are not involved in ensuring stability of frequency. Therefore, if synchronous condensers were not installed, a certain limit would need to be set on the number of grid-connectable power plants using renewable resources. As soon as the set limit is exceeded, due to lack of inertia, the transmission system operator would not be able to ensure frequency stability.
The newly planned synchronous condensers will ensure sufficient grid inertia so that it would be possible to produce in Lithuania much more electricity from renewable sources than is produced now.
3 facilities in each Baltic State
The synchronisation conditions stipulate that in each Baltic State three synchronous condensers will have to operate. In Lithuania, they will be connected to Telšiai, Alytus and Neris (Nemenčinė, Vilnius district) 330 kV transformer substations.
Synchronous condensers are usually installed in places where generation of electricity from renewable sources is growing rapidly. For example, in Australia, installing synchronous condensers is the first thing that builders of wind farms must do.
In Europe, where until very recently traditional thermal or nuclear power plants dominated, such facilities were not required in the past. But as the countries that switch to renewable resources install the increasing number of synchronous condensers, such devices become a common element of the grid, which ensures quality and reliability of electric power in the system. Similar facilities operate in the electricity systems of Ireland, Denmark, Germany, Italy, and Norway.
In the project of installing synchronous condensers, which is partially funded by the EU Connecting Europe Facility, Litgrid is also currently carrying out the procurement of engineering consulting services, the tender for which has been announced in September.
5 synchronisation projects have already been completed
Installation of synchronous condensers is one of the 15 projects of the synchronisation programme of special national importance that has been approved by the Government. The aim of this project is to ensure the reliable and stable work of the electricity system of the country. In addition to this project, works in other groups of projects are also consistently in progress: the LitPol Link connection, which is considered the gateway to the West, has already been expanded and is ready for synchronisation; construction of Harmony Link, the new maritime connection with Poland, is currently in progress; the internal grid of the country is strengthening.
To date, 5 synchronisation projects have been accomplished. These are the expansion of the 330 kV Bitėnai transformer substation, the construction of the 110 kV Pagėgiai-Bitėnai overhead line, the reconstruction of the 330 kV Lietuvos elektrinė-Vilnius overhead line, the expansion of LitPol Link and grid optimization in North-Eastern Lithuania. In total, in Lithuania more than 40% of the work needed for synchronisation is completed. Connection to the continental European grid and synchronous operation with Poland, Germany and other continental European countries will be ensured by 2025 at the latest.
