A theoretical model is presented to estimate the energy requirements of multiple-input multiple-output (MIMO) systems when used in wireless sensor networks (WSN) assuming clustered channel modeling, with Rician distribution and cochannel interference. The effect of different propagation environments is simulated. Simulation results show that the single-input singleoutput (SISO) can only be useful with short range systems (less than 20m). The MIMO system with channel state information has the best performance for applications that require a range more than 20m and under different propagation conditions. The results presented in this paper indicate that increasing the number of antennas for MIMO systems has a negative effect on the performance under free space propagation, whereas it has a positive effect, especially for MIMO with channel state information (CSI), under "severe" conditions.