[en] Over the period 1970-2000, the total primary energy requirements in Egypt have increased from 7.8 million tones of oil equivalent (Mtoe) to 44.2 Mtoe. In the same period, electricity generation has increased from 6.7 TWh to 73.3 TWh. The demand for both primary energy and electricity is expected to continue at higher growth rates in the future due to the ambitious governmental plans aiming at increasing the gross domestic product (GDP) at an average annual growth rate of 8% up to the year 2020. Because of the limited fossil fuel energy resources and the almost fully utilized hydro energy, Egypt has been considering for sometime the various options for satisfying the increasing demand for electricity, including nuclear energy. To this end, the Nuclear Power Plants Authority carried out a comparative study of the various strategies and options for electricity generation in Egypt with technical assistance from the International Atomic Energy Agency (IAEA) utilizing the DECADES Tool. The main objective of the study was to determine the optimal electricity generation mix up to the year 2020, including nuclear and renewable (solar and wind) energies. DECADES is restricted by some limitation that it did not take into its consideration modeling of some energy forms and systems such as simulation of Renewable Energy Options (REO), in particular thermal/solar and wind plants and simulation of Independent Power Producers (IPP). REO and IPP, as well as the nuclear energy option are expected to play an important role in the future electricity generation mix in Egypt. Therefore it is important to consider its effects economically and environmentally when studying the best expansion system in Egypt. This paper presents the modifications for DECADES modeling to enable simulation for the above energy forms and systems, as well as the results of the comparative assessment study.(author)