Solo kata cannot train power, range or timing, imho. For those elements you need a partner.

I agree on the range and timing. I'm not sure about the power. Certainly, if only done all by it self kata will only take you so far. We got to hit things. That's not to say that there isn't some gains to be made by cleaning up sloppy technique while doing kata.
As far as range and timing....they are with an imaginary opponent so they really aren't gonna help you. It's just a prearranged set of moves.


Mark

Kata is synergistic with everything else, by itself it can't do anything.

However, when it combines with all the other stuff you see benefit. The only 'power' training from solo kata is fine-tuning of certain body mechanics, it can definitely effect that, but it will not unless you 1) already have someone teaching you the correct body mechanics and 2) actually know how to use the variations in the kata against someone trying to hit you.

If you have that stuff, then solo practice works as an complimentary practive to the above things, and can give some definite improvement.