Saruman's fireball

[The Only Real Estel]

But it's magic

Although in FotR it talks about Gandalf being 'nearly spent' from his attempts to keep the door shut in the Mines of Moria through spells.

But Saruman might feel no such effects or use as much energy/whatever you want to call it; I suppose we will never know because I don't think any of us here knows the nature of magic. That and no one here knows what PJ was thinking .