Using solar and batteries, you have to have twice the capacity of solar, because how ever much power comes out of the batteries at night, must be put back in during the day.
Using wind and batteries, you have to have twice the capacity of wind, because how ever much power comes out of the batteries at night (when the wind typically dies), must be put back in during the day.
Backing up solar with wind and visa-versa, you have to double capacity again.
Again, How long do we want the battery backup to work?