Have you wondered where the sun will be?
With the position of the sun, you can
* Photography: find the best time taking your photograph.
* Travelling: avoid the strong sunlight.
* Curiosity: learn the suns trajectory in the sky.
* ...
With "insolation", the amount of sunlight coming through a window, you can
* If youre finding a place to live, figure out whats the implication of the window facing.
* Understand why your room is warmer/cooler at certain times of a day