Cybersecurity in smart energy systems, characterized by the integration of CPS and IoT technologies in critical infrastructures, faces growing risks derived from the human factor. This article proposes a theoretical taxonomy to classify the most relevant human errors in industrial energy environments, considering cognitive, organizational and technical aspects. The proposal combines classic models of human reliability with formal error analysis methodologies and international regulatory guidelines. Its multidimensional structure allows a practical application in risk assessment, the design of operational simulations and the development of training programs aimed at reducing the probability and impact of incidents linked to human failure.