This paper describes the early stages of the design process of a 2--DOF parallel mechanism, based on the use of 4--bar linkages and intended to move photovoltaic panels in order to perform sun tracking.Primary importance is given to the search for a way to compensate sun--earth's relative motions with two decoupled rotations of the panel. This leads to devise a kinematic struc-ture characterized by a particular arrangement of the revolute axes. At the same time, the structure itself is designed in order to be slender. Subsequently, the fact that during a day the earth's revolution around the sun has negligible effects on the apparent trajectory of the sun, if compared to the rotation around the polar axis, leads to choose a control strate-gy which, also thanks to the said arrangement of axes, employs only one DOF for most of the daytime. By means of computer simulations is proved that, so doing, are obtained neg-ligible tracking errors. The tracker which employs this strategy has, theoretically, an ener--Proc IMechE Part A: Journal of Mechanical Engineering Science 0(0) gy consumption similar to that of 1--DOF solar trackers but a precision similar to that of 2--DOF ones. KeywordsSolar--tracking mechanisms, 4--bar linkage, sun trajectory, kinematic analysis and simula-tion.