1. A method of generating a state signal that indicates a state of an energy transmission system, the method which comprises: measuring electrical measured values for at least one electrical measurement variable for predetermined network nodes of the electricity transmission system; assigning to each electrical load connected to the energy transmission system predicted load data predicting an electrical behavior of the respective load; assigning each of the electrical loads to an electrical load group in which electrical loads with comparable prediction reliability are grouped together; assigning each load group a respective individual weighting value describing a prediction reliability of the predicted load data of the loads assigned to the load group; and generating the state signal by including the measured values, the load data and the weighting values, the state signal indicating the state of the energy transmission system.