How do cars defrost the rear windshield? Embedded heating elements in the glass. That's pretty proven, and easy to manufacture. The exact same thing could be used here.
That works for frost, but I still need to clear the windshield after it snows. I dunno how hot those defrosters will go if you really crank 'em, though...
Apropos of nothing, but this just made me look up "defroster" on Wikipedia... "For primary defogging, heat is generally provided by the vehicle's engine coolant via the heater core; fresh air is blown through the heater core and then ducted to and distributed over the interior surface of the windshield by a blower. This air is in many cases first dehumidified by passing it through the vehicle's operating air conditioning evaporator." Wikipedia makes everything so cool.
