There is a method to model large electric power consuming facilities for power system studies. A general facility model, for example a template, is created for different types of industrial or commercial facilities. A template includes all necessary and general electric system information such as the common electric network configuration of a specific type of facilities. The template, stored in a database, is then scaled and adjusted based on the power demand level of the case-specific facility to be modeled based on facility specific parameters acquired for the facility. The result is a full, case-specific model of the facility to be modeled. The case-specific model is simplified into an equivalent model with varying details according to a user's specification. The results are the case-specific facility model of interest to the user. The model is normally included into the power system model of the utility network for power system simulation studies.