the trouble with the super solar flare being used as a way of defeating him is it's easy to become too formulaic. Every new villain trying to get him to use the power so they can beat him while he recharges is the same as every single villain having access to a kryptonite. Pretty soon, none of his powers will matter because every single conflict will be based on his post solar flare state.
Azzarello has been doing this with Wonder Woman. Turns out she is the daughter of Zeus, not made of clay, after all. The bracelets are a power inhibitor. When she takes them off, she goes all cosmic and can trash a Greek god (Artemis got her arse handed to her in a single page the first time it happened). But its a heavyweight boxer solution: one punch can kill, so she keeps the bracelets on.
I used to read a lot of Superman as a kid. During the 1960s-70s it seemed half of North America was made of Kryptonite so I understand the concern (every fricking bank robber had Green K in his inside jacket pocket), but hopefully writers are a bit more sophisticated nowadays.
