A novel maximum power point tracking method based on a sliding mode control strategy is proposed to harvest the maximum power from solar panels more effectively by controlling the duty cycle of DC-DC buck converter to which they connect. This method utilises a sliding mode strategy to achieve fast tracking speed and reduced oscillation at steady state. Furthermore, unlike most of other methods which require feedback signals from both voltage and current sensors, this method only requires current feedback information to generate control actions; so reducing the capital cost and the complexity of the system. The system modelling, development of the sliding mode control method, definition of the sliding surface and an analysis of stability are presented in this paper. Numerical results demonstrated that compared with conventional perturbation and observation method, a much faster tracking speed and efficiency improvement up to 5% can be achieved.