Magick is my system so that's maybe why it sounded a bit weird at first
Let's put it this way: In Magick you affect this plane (physical) by affecting higher planes. For example if you wanted to kill someone, you would eg crush his Aura.
Now the Sun problem:
We get two forms of energy from Sun: Light which is visible and heat which is not visible, but for sure can be felt.
Now the light and the heat exists on the physical plane and as you said, you can get eg sunburn from it.
Energy also exists on higher planes and on these planes this energy can be absorbed and added to your own energy, which will result in effect in physical plane (like a solar panel).
Except this energy thing, Sun also has some spiritual basis of power. I am not sure if this power is original or it is egregore created by sun cults.