31.08.2018. After the assessment of dynamic research results and presentation thereof to the European Commission and ministries of the Baltic states responsible for energy, Poland refused to implement the second alternating current link scheduled on their side and stated that Poland is only ready to implement an additional direct current sea cable between Poland and Lithuania.
Considering the above, the TSOs of the Baltic states and Poland, with the support of ENTSO-E, agreed to perform other research on additional measures and costs that are required for the synchronisation of the Baltic states with continental Europe. The aforementioned study was conducted by the Gdansk Institute of Power Engineering according to the order of the TSOs of the Baltic states and Poland in summer 2018.
The study concluded that the option for the synchronisation of Baltic electricity grids with Europe proposed by Poland, which provided for the use of two-circuit alternating current link Alytus-Elk (Poland – Lithuania) and the construction of an additional direct current sea link between Poland and Lithuania could be feasible. In addition to that, and in order to ensure inertia, the installation of synchronous compensators in the Baltic states and, if required, the installation of small capacity energy saving batteries for the adjustment of frequency will be necessary. The aforementioned study recommended to use existing direct current links between the Baltic states and neighbouring electricity networks in Europe, as well as links under construction for frequency adjustment measures and the provision of reserves. Based on the conclusions and recommendations of this and previous studies of 2018, the European Commission, on 14 September 2018, supported the synchronisation of the Baltic states on a political level and recommended to implement further technical steps for the commencement of synchronisation of the Baltic states with continental Europe.