An integrated, passive solar, rammed-earth, Greenhouse Biosphere prototype for rural Canada
ASH-Inc, Jorg Ostrowski © Feb. 10, 2010 draft 2
"All greenhouses collect solar energy. Solar greenhouses are designed not only to collect solar energy during sunny days but also to store heat for use at night or during periods when it is cloudy. They can either stand alone or be attached to houses or barns. A solar greenhouse may be an underground pit, a shed-type structure, or a hoophouse. Large-scale producers use free-standing solar greenhouses, while attached structures are primarily used by home-scale growers.
Passive solar greenhouses are often good choices for small growers because they are a cost- efficient way for farmers to extend the growing season. In colder climates or in areas with long periods of cloudy weather, solar heating may need to be supplemented with a gas or electric heating system to protect plants against extreme cold. Active solar greenhouses use supplemental energy to move solar heated air or water from storage or collection areas to other regions of the greenhouse. Use of solar electric (photovoltaic) heating systems for greenhouses is not cost-effective unless you are producing high-value crops." 1 (see also Solar Greenhouse design 2-5)