In practice this is an interesting problem for ISS. Considering the varying contingent of shadow-casting (and reflecting!) payloads, orbital replacement units,

In practice this is an interesting problem for ISS. Considering the varying contingent of shadow-casting (and reflecting!) payloads, orbital replacement units, visiting vehicles and robotic elements the station's geometry is constantly changing. Then we have to consider system and lifespan effects. Solar array orientation alters the corresponding equilibrium attitude of the station and thereby the need for gyro and thrust stabilization. Along with problems we've had with overuse of the solar array rotary joints, there is a lot to consider after and optimal array orientation is found. Space is expensive.