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Cognitive radio ) CR) is a technology to solve the sacristy problem in the spectrum. One of the major problems is such technology is the high energy consumption especially during spectrum sensing. In this paper a method to improve energy consumption in sensing process is proposed. Theoretical analysis to compute the amount of energy consumed using the proposed as well as in the transmission stage during transmitting a local decision to the fusion center FC method are derived. The proposed sensing method is based on energy detection to detect the presence or absence of the primary user (PU). The proposed method consists of two stages: coarse sensing stage and fine sensing stage. In coarse sensing stage, all the channels in the band are sensed shortly and the channel that have maximum (or minimum) energy is identified to make intensive fine sensing for verifying the presence of PU signal (or hole). The performance of the proposed method is evaluated in two scenarios: non-cooperative, and cooperative in both AWGN and Rayleigh fading channels. The simulation results in cooperative scenario at SNR equals 0 dB showed that the proposed method reduces the energy consumption by 72% as compared with the traditional method based on single sensing stage. The result also showed that 57%, 54% reductions in energy consumption are obtained using the proposed method as compared with TSEEOB-CSSS and CC4C methods that are based on two sensing stages respectively.