A Heating Penalty is
Cool roofs reflect solar energy year-round. In the winter, cool roofs reflect solar energy that could have been used to warm the building, and more heating energy may be required. This Heating Penalty is small in most U.S. climates because there is less sunlight available during the winter. In addition, it is usually offset by cooling energy savings during the summer. Cool roofs typically result in net annual energy savings.
List of books: Heating,Penalty