[6] Until 2024, it was a subsidiary of Greek conglomerate GEK Terna, which through its subsidiary Heron S.A. is as well involved in the construction and operation of thermoelectric power generation fuelled with natural gas.

However, the company produces energy exclusively from renewable energy sources, including wind farms and small hydroelectric plants.

The company was incorporated in 1997 as a subsidiary of Terna, which in 1999 merged with GEK to form Greece's largest conglomerate.

[6] In 2013, U.S. investment firm York Capital Magagement bought a 10% share of parent company GEK Terna and another 3% share of Terna Energy.

[7] In November 2024, it was announced that Masdar had completed the purchase of a 70% stake in Terna Energy for $3.3 billion.