The company owned the power grid and district heating in Trondheim Municipality and Klæbu Municipality, fourteen hydroelectric power plants in Nea and Nidelva, and five partially owned power plants in the Orkla Valley.

Trondheim Energi was founded in 1901 as Trondhjems Elektricitetsværk og Sporvei to build a power plant in Øvre Leirfoss and operate the Trondheim Tramway.

In 1952 TEV and Stockholm Elverk made an agreement where they would cooperate in building the Nea power plant.

In 1982 the district heating system was decided built by the municipal council, with operation starting in 1986.

In 2002 Trondheim city council sold the company to Statkraft.