[wat10000]

Tornadoes are not actually very common in terms of how often you'd expect a structure to be hit by one. You're looking at hundreds or thousands of years between tornado hits even in the most tornado-prone areas. They're numerous, but small.

[customguy]

So what I'm hearing is very sturdy, christmas tree shaped turbines (long blades at the bottom, getting shorter as you go up), on a very heavy central shaft ending in a spike that gets driven deep into the ground by dropping them from great height with planes (there probably needs to be a thruster stage on top that accelerates them beyond mere free fall) into the path of tornadoes. No clue what to do with the energy, but that seems like a minor detail.

[wat10000]

Excellent idea. You don't even have to worry about hitting people's houses and such, since they'll be destroyed by the tornado anyway.