I'm planning on having between 10 and 15 KW of windpower here eventually (right now it's about 1KW), so right now it's not an issue, but in the long term a 'useful' way to use excess energy is a good thing, and plowing driveways here is a much-too-frequently returning chore.
That being said, I don't think that it's possible to heat the whole driveway in one go, it'll probably have to be a system where you heat sections of it.
I figure that with one power 'bus' running the length of the driveway and heater segements that can tap in to that being controlled from some location I may be able to cut that down significantly.
The winds here mostly happen in the winter, which nicely coincides with the need for snow removal.