Initial costs of solar-photovoltaics have remained a significant factor contending against the wide-spread utilization of solar energy. The paper demonstrates that the concept of differential flatness could be used to design controllers for a polar-axis solar tracker that would enable reduction in hardware costs. Key results show that, the implementation of trajectories of motion in the controller can reduce the drive power requirement and associated photovoltaic (PV) cost by about 31%, and enable the use of smaller drive motors with a possible 25% reduction in drive motor costs; and that the implementation of sensorless control in the polar-axis tracking system is able to further lead to sensor cost elimination. (C) 2011 Elsevier Ltd. All rights reserved.