The speculative method is intended to conduct transient states analysis in electrical circuits in which the transient state is described by a system of ordinary differential equations (ODE), linear or non-linear. A general idea of this method is based on the decomposition of the time domain. Computations in subintervals of time are conducted in parallel with the use of one of wellknown sequential numerical methods of solving ODE systems. In the article the modified speculative method, then the analysis of a non-linear model of a DC-motor supplied by a solar generator, as an example of the application of this method, will be presented. The computations were carried out with the use of the cluster of 5 workstations based on Intel Xeon 2.66 GHz processor.