That's why it would be so nice to just forego the static stability you need for an air turbine: a sailboat gets all the stability to push its sail into the wind

That's why it would be so nice to just forego the static stability you need for an air turbine: a sailboat gets all the stability to push its sail into the wind from its movement. It's like the lift of an airplane that is completely gone without movement. So you put up sails (or a powerful traction kite), get to speed so the keel provides the lateral lift you need to not just drift downwind and engage the hydrogenerator to skim off some off the energy.