A Solar Cooker Prototype for a Greener Tomorrow

FURTHER DEVELOPMENT AND OPTIMIZATION OF A THERMAL-STORAGE SOLAR COOKER

Principal investigator:† David Gordon Wilson
Professor of Mechanical Engineering, MIT - emeritus

This note is written because someone unknown has publicized an old highly fanciful and almost wholly inaccurate but beautifully illustrated account (by a small group of business students at MIT) of our solar-cooker work, calling it a "grill", and showing it apparently being used (in highly creative illustrations) by tropical people using devices that have no relation to what we are trying to do. I am having to write to many good people who have reacted with delight at the outrageous claims of performance of this device. The following paragraph is taken from a recent proposal for further work on the real cooker. I am happy and grateful to report that the Tata Foundation has promised 24 months of support for a graduate student to develop the cooker to become a fully working and useful unit.

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The solar cooker is one that stores solar heat in a sealed container of melting salt for about six hours during a tropical day. At a chosen point, such as when all the salt is melted, the cooker (basically a hot-plate hermetically sealed on a stainless-steel pot containing the salt) is automatically fully insulated and can be used for cooking in the evening, three-to-five hours later.† A somewhat crude version of the cooker has shown that the concept is fully feasible, using a solid copper finned hot plate as the interface between the thermal storage and the heating surface. Copper is probably too expensive, and cast-iron has been used in a second version, to lower the cost, but is very heavy. Coated aluminum alloys and other alternatives need to be examined. The absorptivity and emissivity of the solar-receiving area need to be analyzed, tested experimentally, and optimized. The size appropriate to a family or village group must be defined.† A timing system, presumably using clockwork, to keep the cooker aligned with the sunís position during the six hours of insolation needs to be fully developed. The goal of the proposed program is a series of tests of the cooker in tropical-village conditions and the incorporation of the improvements found to be necessary and desirable.

 

Comments

  1. Carol @ Solar Cooks and Carpenters says:

    I would love to do a test drive of one of these for southern Africa. We are currently training Grandmothers to use a box cooker, that works well enough, but this one........mmmmm.
    I volunteer.
    Thanks a bunch,
    Carol

  2. Keep up the good work will enjoy having one of the Wilson solar grill one day soon I hope.

  3. maria young says:

    Where can I buy one

  4. Please let me know when you get to "Kickstarter" or similar stage.

  5. Brian Kohler says:

    If anybody is really interested in building one, they can be made for a very small amount of money. Go to craigslist and get a free rear projection TV and a free gas grill. Take the Fresnel lens out of the TV, and use some superstrut to mount the lens to the grill. I used the lens to heat up a cast iron griddle and then cooked on the griddle. Even in Pittsburgh, I was able to cook chicken. This summer, I plan on experimenting with heating up the lava rocks ahead of time to see if it will speed up the cooking.

  6. William Llewellyn says:

    Water in a container, heated by the sun, evaporates. The loss of water means the container is lighter by the minute. A spring, attached to the container, exerts it's strength more and more as the container becomes lighter, to the effect that the lens is rotated to stay full face to the sun.
    Water minus evaporation, torque turns the lens. Need to work out amount of water and size of container. Imagine container wide mouthed, possibly quite flat.
    Just an idea .

  7. This is an amazing barbeque. how much sunlight do you need for this to work? can you use it during the day? How long does it store the energy for?

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