Daystar: The Solar Greenhouse at the Four Mile Island Solar Home

The greenhouse is really part of a system that includes a ½ acre garden/orchard and a root cellar. Sunlight enters the greenhouse through 220 square feet of double- pane glass and warms eight 18 inch diameter, 5 foot tall, plastic tubes that hold 450 gallons of water and act as a sort of thermal shock absorber by storing heat during the day and giving it back during the night. Probably the most interesting technical feature of the greenhouse is the venting system. Two of the vertical windows and the two vents pictured on the roof open automatically using heat pistons. The fluid inside the pistons expands and opens the windows and vents when the temperature rises. Very cool, (excuse the pun) because the heat pistons don’t use any electricity. The floor is dirt and the dimensions are 10’ by 17’. Originally food was grown during the winter in the greenhouse, but now we find it easier to grow the food outdoors and preserve it. We use the greenhouse to grow several hundred vegetable and flower plants for the garden in the early spring. Root vegetables, such as carrots or parsnips, and some kinds of fruit, like apples and pears, are stored in the root cellar. The root cellar is at the rear of the house, made of reinforced concrete and is covered by about 2 feet of dirt. The water pump for the house is in the root cellar, and the temperature rarely goes below 38 degrees F in the winter. Squash and onions store best at room temperature, and we preserve things like tomatoes and corn by canning them. It is not hard to grow most crops without chemicals and pesticides; it is a true pleasure to eat food you have grown yourself all the year round.


	Back to nature___ Rachel Carson, Food First and Silent Spring... Cesar Chavez, Biafra... Vegetarian, FRUIT-arian, raw food diet, over-Pop_ulation, Green, green rev-O -lution… No, this is not the 60’s and 70’s put to a 90’s rap beat, but it is a taste of the social environment in which greenhouses became popular in the first modern solar houses. Some greenhouses were designed to assist in heating the building to which they were attached. Our greenhouse was designed primarily to grow plants and to never go below freezing without any heating except that provided by the sun. It does both! ...and we have roses in January.
	The greenhouse is really part of a system that includes a ½ acre garden/orchard and a root cellar. Sunlight enters the greenhouse through 220 square feet of double- pane glass and warms eight 18 inch diameter, 5 foot tall, plastic tubes that hold 450 gallons of water and act as a sort of thermal shock absorber by storing heat during the day and giving it back during the night. Probably the most interesting technical feature of the greenhouse is the venting system. Two of the vertical windows and the two vents pictured on the roof open automatically using heat pistons. The fluid inside the pistons expands and opens the windows and vents when the temperature rises. Very cool, (excuse the pun) because the heat pistons don’t use any electricity. The floor is dirt and the dimensions are 10’ by 17’. Originally food was grown during the winter in the greenhouse, but now we find it easier to grow the food outdoors and preserve it. We use the greenhouse to grow several hundred vegetable and flower plants for the garden in the early spring. Root vegetables, such as carrots or parsnips, and some kinds of fruit, like apples and pears, are stored in the root cellar. The root cellar is at the rear of the house, made of reinforced concrete and is covered by about 2 feet of dirt. The water pump for the house is in the root cellar, and the temperature rarely goes below 38 degrees F in the winter. Squash and onions store best at room temperature, and we preserve things like tomatoes and corn by canning them. It is not hard to grow most crops without chemicals and pesticides; it is a true pleasure to eat food you have grown yourself all the year round.
	There were 4.5 billion people on Earth when Four Mile Island (see History ) was built. Today the number is about 6 billion people, and the world population is expected to be approximately 9 billion by 2050 . According to the Food and Agriculture Organization of the United Nations, as of 1999 about 800 million in the world did not have enough to eat. The total productive land area (forests, pasture and arable land) of the earth is 8.5 billion hectares or about 1.5 hectare (roughly 3.5 acres) per person. It will be something on the order of 1 hectare or 2.5 acres per person in 50 years or so . According to the BBC series “State of the Planet,” at present ¼ to perhaps as much as ½ of all plant growth on the Earth is harvested to be used by humans, and due to human expansion, we may lose 50 percent of all plant and animal species in the next 100 years. Just a little Food for thought .


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