Possibly, but they'd have to be designed to be remotely controlled (possibly at an individual level). They'd also have to be specifically engineered to withstand the sudden reduction in countertorque when the windmill is removed from the grid and then to lock the blades against windmilling while shutdown. And of course, to reverse the whole process on command.
I would assume the blades can be "feathered" so as to catch very little wind and not impart a rotational force, as on a prop-drive aircraft when one of the engines needs to be shut off. There has to be some way to take them out of services for e.g. maintenance.
