At night the cycle is repeated, and the stored heat is given up to the cool night air. Designing a passive system for cooling requires some form of daytime shading. A retractable awning or an overhang extension of the roof to shade the glazing from the high summer sun but expose the glazing to the low winter sun will suffice. Moveable insulated panels work better but add to the expense and mechanical complexity. Doors or glazing panels that open will allow the cool night air in to remove stored heat.
Active systems can benefit from shading but work almost as well without it.
Operating the collection system at night reverses the energy transfer. Heat is removed from the storage facility and radiated out the collector. The storage facility can collect the heat of the home during the daytime and expel it at night. Areas that do not experience dramatic temperature swings from day to night or that have warm nights need a heat pump solar system to capitalize on the reverse flow. Areas that experience extreme temperature swings, such as the desert, can construct heat pump systems efficient enough to produce refrigeration.