Electricity utilities have been co-operating for decades, mainly in order to maximise the system's reliability and quality of supply, while optimising the use of primary energy and capacity resources.
Upon the emergence of the Internal Electricity Market (IEM) in the European Union, ETSO was created as an association to respond to the the need for an EU-wide harmonisation of network access and conditions for usage, especially for cross-border electricity trade.
The networks represented by ETSO supply more than 490 million people with electric energy. The consumption of electric energy amounts to approx. 3200 TWh per year. The length of HV (400 and 220 kV) lines covered by ETSO is of more than 290000 km.