Abstract: A self contained, fully automatic, vertical wall panel, solar energy system characterized by having no moving parts in the panel. The panel is substantially a shallow rectangular box having a closed perimeter, an outer insulating chamber which is substantially a double glazed window, and an inner energy storage chamber which is provided with containers of phase change materials. The energy storage chamber is provided with air entrance and exit passages which communicate with the space to be heated. Thermostatically controlled blowers serve to move air from the space to be heated across the containers of phase change material and back to the space to be heated. Thermostatically controlled blowers also serve to move insulating material into and out of the insulating chamber at appropriate times.