I use #include <SolarCalculator.h> to torque my solar panels once every 6 minutes. The library takes Lat/Lon info to calculate sun position info for the day. At the end of the day, I calculate where the sun is going to be for the next day, position the solar cells to meet the sun, and wait for sunrise to start torquing the solar cells.
I use a linear positioning device that does not require power to maintain position. I mounted the solar cells centerline to a pole that the solar cells can rotate around. Once every 6 minutes I apply power to the linear actuator. The linear actuator lifts and lowers one side of the cell array for EW positioning. Power is removed after the cell array has been torqued to a new position. Works great to maximize solar power generation.