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 sun’s 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. There's lots of Solar Cookers out there already but certainly not of this sophistication..should this model pass muster & get off the ground, it would have the potential to be a huge seller (if the price is right & passes environmental concerns)..with electricity cost just gone up in Australia by 30%. I'd very happily put 1 out in the garden & use it every day..AUSTRALIA..the land of Sunshine, Melanomas,Koalas & Kangaroos..

  2. I would love to test and evaluate one of these, with he costs of fuel going up every day this grill should be a hit as long as its performance is at least equal to that of its fueled ancestors

  3. you better get these into production fast, before someone else does. just looking at it I know how to build it.

  4. Sue and Ken says:

    This is a perfect addition to a home that is off the grid. How will it perform in sub-freezing temperatures? That would be important to us here above Latitude 45. Even so, using the solar grill for nine months would be a great addition to reducing the stress on our non-renewable fuels.

  5. What about combing solar with wood chips. I like the taste of wood smoke over propane flame and it would keep it sustainable.

  6. Beautiful design for a really practical concept. If priced right this would be a HUGE hit in Nicaragua where a lt of cooking happens with wood also. Send me a test model guys!!!

  7. The heck with the US and their regulatory BS. Get these into production in developing countries at affordable prices where they can do some real good improving peoples lives, health and nutrition.

  8. Due to regs at my condo association I still could not have the "hybrid" propane and solar. Now electric and solar would be fine... Need options people. I would just prefer solar only. Hmm maybe I'll build my own.

  9. Derek Ham's beautiful visual creations have given people the impression that the "solar grill" is about to be produced. It is not! And it is not a grill but a cooker, one on which meals can be produced in the evening on a hot plate, three-to-six hours after the sun has gone down (NOT 25 hours!) After many years of making unsuccessful proposals to foundations and to the US Agency for International Development I am working on this at home using my retirement funds. And in my 85th year I am not as speedy as I once was. I hope to get a demonstrator (the third generation of the stored-heat solar cooker) working in a few months. I hope that it will then attract enough funding so that we can put ten prototypes for test in various countries, and, after incorporating all suggested improvements, to distribute one thousand. After that it should be ready for mass production at an affordable price, where possible in the countries where they are to be used. Dave Wilson

  10. I'm excited about the model for Africa, but disappointed that the model for US markets included propane. Why bother with solar if you have to have propane with it? The whole idea of solar is to get away from non-renewable fuels. Failure.

  11. Does the sun shine everyday, without cloud cover, in all parts of the United States 364(5) days of the year, Judith?

    Duh.

  12. What a smoke at the African models. Yes these are photo-shopped images of course.

  13. Catherine Lethcoe says:

    I want one...it is the answer for us all...

  14. Tetsuo Shimura says:

    I hope soon you have this product able to export. As you know the north and norteast region of Brazil are granted with shining days all long the year but also, are the region where peoples suffers with no facilities for a normal life such as electric energy, drink water and propan gas cookers. Other idea is to licensing to a local manufacturer in Brazil which should import from the USA the lens and lithiun nitrate. By the way, how long is the life time of the lithiun nitrate?

  15. CAN YOU TEL ME THE PRICE OF THE SOLAR GRILL PROTOTYPE

  16. Guillermo says:

    I would love to buy one of these, either in chrome or the black. I'm sure these things would sell, just depends on how good they cook food.

  17. Frank Kecskes says:

    Curious as to the the lifespan of the Acrylic Fresnel lense when exposed to years of degradation from the sun's UV. What would the replacement cost be of the acrylic lense itself?

  18. Nora Ramirez says:

    When will you have a prototype???

  19. Looking at the snazzy design from another keen solar cookers eyes I love it.I have never used the frenell lens to cook with yet but I know its true power and I would say get a daytime model up and running real soon as many people Im sure wouldnt care right now.
    . You can work on the extended cooking time project into the evenings on your next model that will be financed by the earnings of your first model wich Im sure you could sell millions .If I was filthy rich I would finance your project but Im not but would love to have a licence to sell them but you have nothing yet .Im going to google up for a frenell lens right now good work guys good luck and oh hurry up.You surely will have stimulated the thoughts of many inventors designers like myself.

  20. Havel J Nieman says:

    How much are the solar grills

  21. Sue Hamilton-Flory says:

    I would love to take some of these to Haiti where they have cut down almost all the trees already. They need it badly. Will there be an inexpensive model?

  22. Stupid! They have a fire burning in the background in a pit. Whose idea was that?

  23. CindraLu says:

    Wow! What a great idea. I would love to have one of those. Those would be perfect for out here in the desert. I can see these as being popular in tech countries as we try to use less wood, fuel, charcoal; and being extremely helpful in less developed countries.

  24. Peter Krutiak says:

    Hello,

    Can who ever posted this article please contact me by e-mail. I would like to find out who is doing the prototyping and how far along it is.

    Thanks!

    Peter

  25. great invention but unfortunately the photo of them in africa looks photoshopped?? they look like they are floating with bizzare shadows, nice idea but truly give them to those in need not just fool us into thinking you already have...

  26. M J C Rajesh says:

    Hi I would like to market this product in India is it up for sale yet? this will be a grate blessing for India.
    kindly get in touch with me.
    Regards Rajesh

  27. Hi there to every one, the contents present at this web page
    are actually remarkable for people experience, well, keep up
    the nice work fellows.

  28. Pedro Gracoeiro says:

    Need direct contact for dit or manufacturer, for the African Market.

    B.Regards

    Pedro

  29. I would like to get one of those grills as soon as they hit the market, are they available yet? I am thinking of building I house as self efficent as possible and a solar grill would be a great asset to it..

  30. Dan Haywood says:

    This is an awesome invention! Way to go Mr. Wilson! Good luck to you and please keep up the good work Sir!

  31. Crystal says:

    Can it be purchased? My in-laws in Mexico would love this, is it available for purchase...the one that is pictured in Africa.

  32. Crystal says:

    Reading is fundamental.....Mr. Wilson, I did read your comments and I understand. I also understand the redtape....this will certainly change the game....so I understand the hurdles. What about selling the plans directly foreign countries so that they can produce and test themselves?

  33. Crystal says:

    Mr. Wilson...I would volunteer my time to assist you...this product really needs to get out to the world.

  34. I would be seriously interested in becoming a dealer for sales in my region of Northern California / Southern Oregon. Contact me ASAP when you figure this thing out. Thank You !

  35. Want one & I mean it....

  36. David Hendrix says:

    @Dave Wilson, I currently live in the Philippines and would be more than happy to assist in testing your invention here in the rural provincial areas. I would be willing to shoulder all the cost of testing. If you are interested in a testing partner, please email me at dhendrix@nlaconsulting.com

  37. I would love to try one of these units!
    I live in N.W.Ont. Canada & wonder if these would get enough sun, through a south window, during the winter months?

  38. 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

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

  40. maria young says:

    Where can I buy one

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

  42. 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.

  43. 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 .

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