The Solar Panel Small is a small-sized, single docking-port module used for supplying power to space stations. Like other parts that generate power, it can recharge drained batteries. It produces 54 units of Power, of which it uses 2 and its solar panels retracts when it is turned off.
The panel is launched with the docking port facing outwards from the tug. The panel's lack of a second port, like found on the Solar Panel Large, can cause issues when rearranging the part.