In fact, from 1956 to 1958 (just after the independence), our country leans on 4 water turbines totalizing an installed capacity of 27 MW, in addition to a few diesel groups.
During the sixties, 4 thermal groups (with heavy fuel), of the stage of 30 MW, were put in service at Goulette II. It is the first modern thermal power station of our country.
The 70 decade was characterized by the massive introduction of turbines with combustion (20 to 30 MW). The relatively short duration of construction of this mean of electrical generation allowed facing the fast growth of the request. The deployment of these unities on our national territory allowed the improvement of the electrical network security.
The vertiginous rise in the price of the hydrocarbons (heavy fuel), as a result of the oil crises, had called in question a lot of orientations. From now on, the priority is granted to saving the energy and finding a mean of electrical generation with low fuel specific consumption.
The 80 decade, was marqued by the introduction of the stage 150 MW. The size effect allowed a significant profit on the specific consumption. The direct passage from the stage 30 MW to the stage 150 MW was made possible by the realization of four lines of inter-connection with Algeria and the transverse line connecting Sousse to Tajerouine.
In addition, the fast development of the generation park and of the transition's network required the realization of a national dispatching center and two regional centers (Tunis & Ghannouch) in order to optimize the control of this unit and to provide a better quality of service to the customers.
The nineties the STEG meets its mutation as a company which seeks to satisfy an increasingly request of energy to a company which listens, planificates and undertakes. In short, which lives in harmony with its environment.
Finally, one hundred year after the installation of the first electrical group in 1907, the STEG projects to pass, with the horizon 2009, to the stage 300 MW by bringing into service its first single shaft combined cycle and by extending its wind park to 170 MW.