The door must be hinged, it also has a braking system to prevent it from rotating too quickly. Adding resistance to drive a generator in place of heat/sound generation seems not unreasonable. In cars I think they call it regenerative braking.
Of course an analysis of the heat loss path will help to determine if this is worthwhile or if the heat can be used more directly to aid heating the building.
A regenerative system on a door that has brushes that cause friction with the sides isn't going to make more power than it will cost to create a regenerative braking system in the first place. It adds a whole layer of complexity that will affect reliability and in the end it's going to 'save' piddly little bits of power.
If you take the cost of an energy storage system you have to divide the price of the unit by the amount of power that you can buy for that money discounted with what you think power will cost over the lifetime of the unit.
Of course an analysis of the heat loss path will help to determine if this is worthwhile or if the heat can be used more directly to aid heating the building.