I'm looking to design a system that can control a solar panel through an electrical actuator for a range of motion of -45 to +45 degrees for maximum solar exposure. The panel will be mounted on a 10 feet pole and will be attached at the center of that pole. This means that either the mechanism will be at the pole's top or at least some kind of bearing to allow for the movement.
The caveat in this case (because the panel is attached high up) is that due to security reasons the system must be designed in such a way that the panel will be held stable (mustn't rotate and mustn't fall off) without relying on the actuator itself, in case of power failures.
I've started looking around for actuator mechanisms but haven't yet found anything that talks specifics about similar security requirements. I'm looking for pointers / ideas as I'm not yet experienced in such cases.
PS: For anyone who would be interested in numbers the panel weighs about 150 kg and will possibly receive a horizontal wind force of 300N. Also a torque of 100Nm will need to be applied in order to change its facing direction.