The hobby farm has a passive solar greenhouse. It has been several years in the making and the winter of 2012-2013 was the first year that we were able to grow winter greens in it. The greenhouse idea was first conceived by Nathan who completed the research and design phases. It then became a project for the whole family to construct, mostly on weekends.
It is a heavily insulated building with south facing glazing. Water in containers is used to collect the warmth of the sun during the day and disperse it after sunset as the building cools overnight. Our original hope was that we could keep it warm enough overnight without supplemental heat but that was not to be. Our plan is ever evolving and our next step will be a system to capture the hottest air at the highest point of the building and recirculate it around the water containers to improve the function of our thermal mass.
Our goal is to raise nutrient dense greens throughout the winter and then as the winterr is winding down to raise plant starts for the summer garden. We are hoping to be able to grow enough to feed our families and have some to sell for profit either through a CSA or farmer's market.