Frans,
Yes, that's closer to what I was thinking. Oh course the devil is in the details. This would take lots of force without getting out further from the hinge-point, and it is not a linear path (as shown). Perhaps hydraulic over electric. The cylinder retracts under pressure, but stays clear of the mechanism otherwise.
I was initially thinking something simpler still... If there was a ratchet/pawl that could be engaged remotely, you could just let the wind furl it (at some point, perhaps not exactly when you'd like), but not allow it to open until after the inspection, repair, maintenance. This mechanism would take very little force to engage it.
What I do like about all of these strategies - i.e. furling tail, pitching blades, motorized yaw - is that they are generally passive, controlled. Comparatively, the brake-shorting method puts a pretty abrupt hit on things. And, if the alternator is in trouble to begin with...well, a run-away is a frightening thing.
~ks