Until the late 1950s, most staff at the Electricity Supply Board (ESB) were represented by the Amalgamated Transport and General Workers' Union.
In 1959, a strike among clerical staff at the ESB was unsuccessful, and this led the clerical section to found a new union, Electricity Supply Board Officers' Association (ESBOA).
It affiliated to the Irish Congress of Trades Unions in 1976.
David Begg became its general secretary in 1982, serving for three years.
[2][3] By 2012, the union also had members working for Endesa, EirGrid and Airtricity, and as a result it renamed itself as the "Energy Services Union".