Peaks and valleys affecting the efficiency of the power system can be detected by analyzing the load curve. These oscillations are caused by changes in consumer behavior, mainly consumers in the residential sector. This paper presents the use of fuzzy logic systems to model human behavior related to activation of appliances and lighting at home. Based on this model, the hourly activation profile for each appliance can be obtained and, subsequently, the load curve of the residential sector can be calculated. This model aims at contributing to the simulation of strategies for demand-side management. (C) 2013 Elsevier Ltd. All rights reserved.