The Earthen Solar Cooker is a low cost and low environmental impact design envisioned by Bart Orlando  for use by the poor in refugee camps and in villages of non-industrialized nations. The design is simple; a large parabolicly shaped hole in the ground lined with reflective materials such as salvaged pieces of broken glass mirror or reflective can lids. As part of a food aid program to prevent stunting of malnurished children, pallets of one gallon stainless steel canned vegetables would be airlifted to remote refugee camps and villages. The can lids would be specially designed to be smooth, mirror finished stainless steel surfaces which could then be used as reflectors and meal serving plates. The performance of the lids in terms of not only strengthening the sealed can but also as reflectors and serving plates would each be ehanced by designing the lids with a slight parabolic shape. The remaining can cylinders could be used to fashion rocket stoves or solar cooking/water pasteurizing pots once blackened over a wood fire. Approximately fifty 0.5 meter diameter mirror finished stainless steel vegetable can lid reflectors would be collected each day by 10am and used to line the sides of the Earthen Solar Cooker. The mirrors reflect and concetrate sunlight to the base of the hole where 10 one gallon black containers of water can be boiled per hour and used for drinking or food preparation. (A 2.5m diameter hole, 1.5m deep cooks 10 gal of rice/hr from 11am to 3pm on an 85f summer day in south central Oregon.) Cooking/water boiling containers are accessed via steps carved into the side of the Earthen Solar Cooker. The plates would be redistributed with servings of the solar cooked food. When cleaned, the reflective plates can be used as person grooming mirrors (enhanced by parabolic curature) until collected the next morning for solar cooking again. The plates rest upon salvaged nails pressed into the sides of the hole or upon narrow ledges sculpted along its inner circumference. Each reflective plate would be less than half the diameter of the larger aluminum sheet metal mirrors shown in the image above. This would allow the final reflective surface lining the sides of the hole to conform better to its parabolic curvature, thus making possible a more tightly focused concentration of reflected sunlight near the vertex (center of the bottom of the hole), yielding an even higher temperature there capable of baking bread and pizza. Since the power of a parabolic concentrator is proportional to the surface area of it's aperature (A = 3.14 x r^2), doubling the radius of the hole increases the power of the Earthen Solar Cooker by a factor of four. A (vegetarian) solar barbeque pit may be possible. An Earthen Solar Concentrator the size of a small amphitheater might be capable of casting bronze or boiling the water near the surface of a shallow well located at the vertex, thus making possible the creation of a solar bubble pump that could lift pasteurized water to a tank above ground level.
As camp conditions improve, a more estheticly pleasing mosaic of broken mirrors and colored bits of glass or tile can be set in an earthen plaster lining the inside of the hole. Such a design could be integrated into public mosaic art projects, adding another dimension to the finished work; the integration of art and function in a way that provides for the basic survival needs of pasteurized drinking water and a public place for the people to gather and cook food without having to collect and burn wood. The Earthen Solar Cookers also function as a water catchment while it rains and if installed on the top of a large mound of raised earth, a drain pipe can be included to fill containers. The east and west facing side walls of the mound would provide additional space for adjacent Earthen Solar Cookers permanently positioned to receive either the morning or late afternoon sun for cooking breakfast and dinner.
The broken glass mirrors set in a hole in the ground, one might interpret as a poetic reference to an ancient myth that if the pieces of a broken mirror were collected and buried in the ground, an otherwise ensuing spell of bad luck could be vanquished. To the people of a culture predating medical science, water born illness might have been attributed to bad luck or an evil spell. Could it be that this ancient myth is all that remains in mankind's collective memory of a now long forgotten solar technology of preventive medicine?
At this moment, 80% of all the people on Earth who are physically ill are suffering the effects of waterborne diseases caused by pathogenic microorganisms that can be neutralized by pasteurization of water at 160f. Thousands of people die needlessly everyday of water borne diseases over two million per year! Also today, one billion women are required to find and carry firewood over ever greater distances for their in-door three stone cook fires, subjecting them to the inhalation of wood smoke and eventially, enphysema. The Earthen Solar Cooker is designed to address both of these calamities.
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