Explanation:

About ENTSO-E
European Network of Transmission System Operators (ENTSO-E) represents 39 electricity transmission system operators (TSOs) from 35 countries across Europe.
Thus its members include both European Union (EU) and non-EU member states. ENTSO-E has its headquarters in Brussels, Belgium and it operates the world’s largest interconnected electrical grid.
ENTSO-E was established in 2009 and given legal mandates by the European Union’s third Package for the Internal energy market to liberalize gas and electricity markets.