Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Annualized Geo-Solar enables passive solar heating in even cold, foggy north temperate areas. It uses the ground under or around a building as thermal mass to heat and cool the building. After a designed, conductive thermal lag of 6 months the heat or cold is returned to the inhabited spaces of the building. In hot climates, exposing the collector to the frigid night sky in winter can cool the building in summer.