IMO I'd rather not have any ability/movepool changed unless it affects the meta game in a negative way, and even that has its own discussion.
With that said, solar power is already a very busted wall breaking ability, making zard pick flamethrower most of the time without worrying of even type disadvantages. The only mon I know that can even survive it and its other coverage move solar beam is Altaria (and well Chansey/Blissey). The ability is perfect imo and doesn't need any buffs.