Demirel worked in the state department for electrical power planning in 1949. He undertook postgraduate studies on irrigation, electrical technologies and dam construction in the United States, first in 1949–1950, then in 1954–1955. During the construction of the Seyhan Dam, Demirel worked as a project engineer and in 1954 was appointed Head of the Department of Dams. As of 1955, he served as Director General of the State Hydraulic Works (DSİ). As such, Demirel supervised the construction of a various power plants, dams and irrigation facilities. Eisenhower Fellowships selected Suleyman Demirel in 1954 to represent Turkey.