Student Invents Solar-Powered Fridge

Posted on January 23, 2009  Comments (14)

solar powered refrigerator illustration

Student Invents Solar-Powered Fridge for Developing Countries

21-year-old student/inventor/entrepreneur Emily Cummins has designed a brilliant portable solar-powered refrigerator that works based upon the principle of evaporation. Employing a combination of conduction and convection, the refrigerator requires no electricity and can be made from commonly available materials like cardboard, sand, and recycled metal.

Simply place perishable foods or temperature-sensitive medications in the solar refrigerator’s interior metal chamber and seal it. In-between the inner and outer chamber, organic material like sand, wool or soil is then saturated with water. As the sun warms the organic material, water evaporates, reducing the temperature of the inner chamber to a cool, 6 ºC [43 ºF] for days at a time!

After winning £5,000 from York Merchant Adventurers for her idea, Emily delayed going to college for a year to take her refrigerator to Africa for further development.

At 16 Emily won a regional Young Engineer for Britain Award for creating a toothpaste squeezer for people with arthritis, and the next year went on to win a Sustainable Design Award for a water-carrier made from wood and rubber tubing. In 2007 Emily was named the British Female Innovator of the Year, and last year was short-listed for Cosmopolitan’s 2008 Ultimate Women of the Year Competition.

Update: some readers seem confused by what related means below. Those links show previous post to related items and include previous similar designs to keep things cool, including “Refrigerator Without Electricity” which is a clay pot design by Mohammed Bah Abba of Nigeria for the Pot in Pot Cooling System that received the 2000 Rolex award.

Related: Refrigerator Without ElectricityCompressor-free Refrigeratorposts on appropriate engineeringUK Young Engineers CompetitionsWinter Air RefrigerationThe Glove, Engineering Coolness

14 Responses to “Student Invents Solar-Powered Fridge”

  1. chethan
    January 25th, 2009 @ 5:02 am

    The idea sounds good and relevant in the present scenario of perishing energy resources. Conventional refrigerators also have disadvantage of using CFCs. This model, if can be developed into more robust one and make it commercially viable, it would be fantastic.

  2. rolandas
    January 25th, 2009 @ 1:42 pm

    I was amazingly surprised when the message about this fridge appeared to web. This shows how simple can be some solutions and inventions. Solar fridge – great idea.

  3. curiouscat
    January 26th, 2009 @ 10:56 pm

    Several people posted comments with links to similar previous refrigerators. The related links in the post show previous articles here on exactly the items they referred to. If the comment says something worth reading, I will post it. Comments that just say what about this thing from before (without even mentioning that the very post they are commenting on already links to that exact item) hardly seem worth posting. So, since this is my blog, I don’t.

  4. Anonymous
    January 26th, 2009 @ 11:23 pm

    Very great idea! I think it’s not only very useful to the developing countries, but also very helpful to disaster areas!

  5. Vish
    January 29th, 2009 @ 7:28 am

    Ever heard of the principle of working of earthen pots…??? These pots keep foodstuff cool in the way described above….a simple solution used in ancient time was to have a small platform in water with the food stuff on it…an inverted earthen pot was placed on the food stuff and a wet cloth on the earthen pot ….the perimeters of the cloth were constantly in touch with water….as the water on the cloth kept on drying the capillary action sucked up water around the periphery….keeps food cool at a much cheaper price……

  6. anna
    January 29th, 2009 @ 11:09 am

    The irritation I felt when reading your post is the article’s titel: Student INVENTS Solar-Powered Fridge for Developing Countries. This is not an invention of hers. It is an old invention (of Mohammed Bah Abba indeed, as you wrote in your update) but somewhat modernised, that’s all.

  7. Michael
    February 2nd, 2009 @ 3:32 am

    The Fridge is a great idea for developing countries but I can’t really see it taking off in the developed world. In the developed world you just get a bag of ice from the local service station.

    However, I am sure that Emily well be a great inventor and do very well financially out of it.
    A great mind for a 16 year old.

  8. Colin
    February 25th, 2009 @ 9:20 pm

    As stated before, Emily Cummins didn’t invent a thing. Mohammed Bah Abba came up with that, and his idea is better, because it uses widely available materials. I guess he wasn’t white enough to be recognized in this blog.

  9. curiouscat
    February 25th, 2009 @ 10:13 pm

    I not only posted about that in April of last year, the very first related link on this post goes directly to that post. We commented and updated the post last month saying that many people commented without even bothering to read the full post (quoting from above: “Those links show previous post to related items and include previous similar designs to keep things cool, including ‘Refrigerator Without Electricity’ which is a clay pot design by Mohammed Bah Abba of Nigeria for the Pot in Pot Cooling System that received the 2000 Rolex award.“). It seems very dishonorable (and fairly inept) to me, to make such a critical and baseless accusation, that is disproved on the very page on which you make your accusation.

  10. Jen
    March 5th, 2009 @ 4:38 pm

    It is amazing how creative some of these college students are. What a wonderful country America is.

  11. Tim
    March 7th, 2009 @ 8:12 pm

    Last I heard, Emily is a BRITISH inventor – so America may be a wonderful country, but for general inventiveness, the British take the biscuit.

  12. Adam
    March 9th, 2009 @ 7:56 am

    This is a great idea, but I can see one problem. It says she plans to take the fridge to Africa. Well correct me if I’m wrong but isn’t Africa very, very dry in most parts. Which would you rather have? Water to drink or water to keep food cold? Another thing I’m wondering about is how often you have to re-wet the material. I’m sure it would vary depending on what kind of material it is (e.g. sand, cotton or soil). Also how well would it work on a cloudy day? Don’t get me wrong. I’m not trying to take anything away from this girl. She has come up with a ingenious solution to a problem. I’m just wondering if she has thought it all the way through.

  13. BenM
    April 28th, 2009 @ 3:11 pm

    Great idea – and this technology can be made to work really well – there are Australian coolers that have worked on similar principles that are over 100 years old. Refining the design is great (so long as it remains affordable), but is it indeed solar powered?
    The cooling comes from evaporation, not from solar heat. The latent heat of the water is taken up as the water evaporates, so this cooler will work better in the shade than in direct sunlight. The air needs to be dry, of course.
    Will work less well as the humidity increases – so it will work great in a dry desert (when fed with enough water), less good in humid tropical rainforest. As the air humidity approaches 100% so the cooling effect will tend towards zero (think: damp shirt on a really hot, humid day). Test what I say – you will find it to be so.
    For solar powered cooling check out the ISAAC icemaker and its cousins.

  14. Chuck
    August 26th, 2009 @ 2:32 pm

    The common definition of “invention” is not that used by patent offices, and even their interpretations may change.

    At the least, this has the right to a design patent.

    As has been noted, evaporative cooling has been used pretty much throughout human history, and no doubt it has been invented and reinvented many times (as many things are.)

    Note that the patent office requires that the technique cannot be “…obvious to practitioners of the art…” This means that something that is well -known in one generation, may be completely unknown in the 2nd or 3rd generation after. For instance, most of the clever analog circuits are no longer part of the newly graduated electronics engineer–they are thought to think in terms of digital logic.

    As a functioning refrigerator, this design is not particularly practical, since everything in the device must be lifted to retrieve any item.

    It also will not work if the RH is too high–not my ideal choice in Britain. as has been pointed out, it also is a problem if water is expensive..though it one could be designed to condense and retrieve the water.

    It also requires the device to sit outside, not where I want my food.

    For my money, I’d build a sealed absorption refrigerator, and design it so that the heated end could be placed in the focus of a solar cooker–thus using the sun to cool the food, and to cook it. Such equipment is not difficult to build and like all refrigerators (other than this one! the food keeping area is basically an insulated box.

    It is also possible to use a parabolic solar collector (with a focus device changed from IR absorbent to IR transplant,) point this at the polar night sky and it will radiate heat quite well. This is also not new, as it was used at least as far back as the Persian Empire to make ice (they build stone walls running east-west and put shallow pans of water on the north side at night..a combination of evaporation and radiation cools the pans.

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