A method and system for the passive solar energy induced storage and use of thermal energy at both high and low temperatures, comprising a collector (76,110) communicating with the atmosphere for collecting air acting as a carrier for thermal energy, an underground thermal storage reservoir (78,112) having a capacity sufficient to store thermal energy for substantially an entire heating or cooling season, and a solar chimney (82) providing convection means for at least in part inducing the natural circulation of air from the atmosphere into the collector into and through the thermal storage reservoir, and outwardly from the reservoir back into the atmosphere, to transfer thermal energy between the collector (76,110) and the reservoir (78,112).