Upon the emergence of the
Internal Electricity Market (IEM) in the European Union, the leaders
of the four above-mentioned regional organisations recognised the need
for an EU-wide harmonisation of network access and conditions for
usage, especially for cross-border electricity trade. In 1999, ETSO
was created as an association with ATSOI, UKTSOA, NORDEL and UCTE as
founding association members. However, on 29 June 2001 ETSO became an
International Association with direct membership of 32 independent TSO
companies from the 15 countries of the European Union plus Norway and
Switzerland. At the end of 2001 ETSO membership was enlarged to
Slovenia and CENTREL countries as full and associate members
respectively. The Czech Republic was admitted as full member in June
2003 and Hungary, Poland and Slovakia in 2004.
The Estonian TSO has become ETSO Associate Member in September 2004
and the Lithuanian TSO in February 2005.
The networks represented by ETSO supply more than 450 million people
with electric energy. The consumption of electric energy amounts to
approx. 3000 TWh per year.