Synchronous grid of Continental Europe



The synchronous grid of Continental Europe (also known as Continental Synchronous Area; formerly known as the UCTE grid) is the largest synchronous electrical grid (by connected power) in the world. It is interconnected as a single phase-locked 50 Hz mains frequency electricity grid that supplies over 400 million customers in 24 countries, including most of the European Union. In 2009, 667 GW of production capacity was connected to the grid, providing approximately 80 GW of operating reserve margin. The transmission system operators operating this grid formed the Union for the Coordination of Transmission of Electricity (UCTE), now part of the European Network of Transmission System Operators for Electricity (ENTSO-E).

Area
The synchronous grid of Continental Europe covers territory of the ENTSO-E Continental Europe regional group and some neighboring countries not involved in the ENTSO-E. The synchronous grid includes part or all of Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark (western part), France, Germany, Greece, Hungary, Italy, Luxembourg, Montenegro, the Netherlands, North Macedonia, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, and Switzerland as a members of the ENTSO-E Continental Europe regional group. In addition to the ENTSO-E members, the small west electricity island of Ukraine is synchronized with the grid of Continental Europe. Albania is operating the national grid synchronously with the synchronous grid of Continental Europe. The grids of Morocco, Algeria and Tunisia are synchronised with the European grid through the Gibraltar AC link and form the SWMB. In April 2015, the grid of Turkey was synchronized with the European grid.

Although synchronous, some countries operate in a near island mode, with low connectivity to other countries. The European Commission considers high connectivity to be beneficial, and has listed several interconnection projects as Projects of Common Interest. However, the national grids must also be upgraded to handle increased power flows if the values of a free energy market are to be realised in the EU.

On 16 March 2022, during the 2022 Russian invasion of Ukraine, the ENTSO-E set up synchronisation with the networks of Ukraine and Moldova on an emergency basis to provide external support for the power supply in those countries. (Plans for Ukraine to shift from the Russian grid to the European grid were already in progress, with an experimental disconnect from the Russian grid underway when the invasion occurred. ) Power exchange and integration gradually increased, and by August 2022, 400—700 MW were sent from Ukraine to Eastern parts of EU.

List of electricity interconnection levels
Electricity interconnection as percentage (EIL = electricity interconnection level) of installed electricity production capacity in 2014; the EU goal of at least 10% for 2020, and 15% for 2030.

Alternative formulas for calculating interconnection levels are based on peak load instead of installed capacity.

Some border transmissions, particularly around the Alps, have both high utilization rate and high price difference, implying that further transmission would be beneficial.

Interconnections
The British grid is not synchronized with the Continental Europe frequency, but it is interconnected using high-voltage direct current (HVDC) via the HVDC Cross-Channel, BritNed, Nemo Link, IFA-2, North Sea Link, Viking Link and ElecLink links. In 2014, before Nemo Link, IFA-2, ElecLink and North Sea Link became operational, the United Kingdom's electricity interconnection level was 6%.

The networks of Ireland and Northern Ireland form the ENTSO-E Irish regional group, which is not yet interconnected with the Continental Europe grid, but has DC interconnections with the British network through the HVDC Moyle Interconnector and the East–West Interconnector.

Similarly, the Nordic regional group of ENTSO-E (former NORDEL), composed of Norway, Sweden, Finland and the eastern part of Denmark (Zealand with islands and Bornholm), is not synchronized with the Continental Europe, but has a number of non-synchronous DC connections with the Continental Europe grid. Gotland is not synchronized with the Swedish mainland, as it is connected by HVDC.

The network of ENTSO-E Baltic regional group, composed of Lithuania, Latvia and Estonia, currently part of the IPS/UPS system, is interconnected with the Nordic grid at an electricity interconnection level of 10% through the HVDC Estlink cables and NordBalt cable, which is functioning since 2015. The Baltics are also connected with the Continental Europe grid through the Lithuania–Poland interconnection.

The networks of Iceland and Cyprus are not yet interconnected with the other grids. Malta is connected up to 35% via the Malta-Sicily interconnector, commissioned in 2015.

Future extension plans
ENTSO-E is studying the following extensions:
 * Tunisia–Libya synchronous connection: to synchronise the Continental Europe with Libya, Egypt, Jordan, Syria and Lebanon (the latter five countries constitute the SEMB of the Mediterranean Electricity Ring project), in addition to others projects in the Mediterranean sea not necessarily relying on a synchronous connection, such as:
 * EuroAsia Interconnector HVDC project between Greece, Cyprus, and Israel,
 * DESERTEC concept.
 * ENTSO-E Baltic regional group synchronous extension: to disconnect only these networks from the IPS/UPS system and synchronously interconnect them to the synchronized grid of Central Europe. On 22 April 2023 a trial was scheduled in the Baltic states to test the infrastructure and operate for a day outside of IPS/UPS. On 16 July 2024, the three Baltic states formally notified Russia and Belarus of their decision to withdraw from the BRELL agreement. The agreement will legally expire on 7 February 2025 and the Baltic states will technically disconnect from IPS/UPS on 8 February 2025.
 * ENTSO-E Nordic regional group synchronous extension.
 * Turkey-Iraq synchronous interconnection: in the past the Armenia and Turkmenistan networks were part of the Soviet unified system, but currently they are connected to the Iran grid.