Chinese Greenhouse
There is a special type of greenhouse that is common in China but largely unknown in the rest of the world. These originated in the 1970s and 80s and have been promoted by the government in China. To maximize solar heat collection, this type of greenhouse is facing south but has solid walls on the north(back), east and west side. Another feature is that it can be covered with insulating material at night (straw mats, other), which is then rolled up again in the morning. Most of these greenhouses do not require extra heating during the cold season and yet still manage to avoid freezing temperatures. The precise geometric configuration depends on latitude. All sorts of variations exist, from very low-tech, build-it-yourself versions with simple materials (bricks, rammed earth, bamboo, etc.) to very high-tech versions (steel, ventilation). The articles below have much more information and photos.