A solar panel having venting gates at opposite ends of an air plenum defined between a collector element and a protective, light-transmissive cover and having a wax thermal actuator for both the gates and flexible force-transmitting linkages between the actuator and each gate to operate the gates simultaneously. Preferred embodiments include certain linkages, gates and gate control apparatus, and certain structural relationships of the actuator with the collector element to achieve desired heat transfers. In certain embodiments, the actuator is part of a heat-sensing module which receives a multiplicity of heat inputs. The collector element in certain highly preferred embodiments is of plastic. A glazed solar panel having a venting gate controlled by a temperature-responsive wax thermal actuator linked thereto.