Community ProjectsProcessing & Food Preservation

A Refrigerator that Runs Without Electricity

Sometimes there are simple solutions to universal needs that don’t require coal fired electricity, fossil fuels, or even solar panels or wind turbines.

Around a third of the world’s population have no access to electricity. If you’re like me, you’ve spent your entire life being able to plug in. Do we ever give a thought to what life would be like if the various appliances we’ve come to rely on were to suddenly stop working? One of the most energy guzzling appliances in our carbon footprint portfolio is the refrigerator. But, unplug it, and the quality of your life will suddenly deteriorate. Take that thought, and imagine living in a hot dry country in Africa, without electricity, where food quickly wilts and rots in the sun, aided by onslaughts of flies.

One modern day genius, mindful of this basic need to preserve food, has solved the problem for many. Mohammed Bah Abba, a Nigerian teacher, invented the ‘device’ — a refrigerator that doesn’t require electricity!

From a family of pot-makers, Mohammed has made ingeniously simple use of the laws of thermodynamics to create the pot-in-pot refrigerator, called a Zeer in Arabic.

Here’s how it works.

You take two earthen pots, both being the same shape but different sizes, and put one within the other. Then, fill the space between the two pots with sand before pouring water into the same cavity to make the sand wet. Then, place food items into the inner pot, and cover with a lid or damp cloth. You only need to ensure the pot-in-pot refrigerator is kept in a dry, well-ventilated space; the laws of thermodynamics does the rest. As the moisture in the sand evaporates, it draws heat away from the inner pot, cooling its contents. The only maintenance required is the addition of more water, around twice a day.

To give an idea of its performance, spinach that would normally wilt within hours in the African heat will last around twelve days in the pot, and items like tomatoes and peppers that normally struggle to survive a few days, now last three weeks. Aubergines (eggplants) get a life extension from just a few days to almost a month.

Inventing the refrigerator in 1995, Mohammed distributed thousands around Nigerian communities during the late 1990s (initially for free to get the word out, then later at just production-cost price), and subsequently won the Rolex Award for Enterprise in the year 2000. It has improved the lives and health of thousands. Less work can translate into more education for children, and small farmers who were before losing large proportions of their harvest are now able to earn a better income. Another knock-on benefit is improved health due to better preservation of vitamins, as well as a reduction in health problems like dysentery due to the separation of food and flies.

It seems that not all the answers to life’s needs have to come with a plug and instruction book.



  1. Overjoyed. I’m now convinced that we can reduce our energy consumption to at least 1/10th of what we currently use without altering our quality of life in a negative way.

    This was the last piece in the equation.

    Post more info if possible.

    I think it needs a plastic pull out lining which would hold all the food, so you could grab your bucket of chilled vegies take what you needed and then return the lot to the chiller.

    In fact we could probably chill entire shopping centers using this porus material and sand/water combination. Its just a different approach to the cooling towers we currently use with water sprayed into a tower and air passed through it. Maybe the porus material could be on the roof and the natural air and sun would cool the building by evaporation. If there was a glass ceiling over it the water could be collected and recycled. If it were clean Sea Water the salt and the pure fresh water could be collected, and no chemicals need be used to keep the air sterile. The only problem shopping centers have is cooling as the heat load of the people, lights, refrigerators (see its related!) heats the building many times over. Just another example of the sickening waste which our industrialized cities perpetuate through no concern for the energy consumption needed. Fortunately legislation is changing, but make sure that if any building goes up near you it is five or six star energy rated. Its up to you! Six star means it has innovative technology for saving energy and is pushing the limits to new levels. Any energy hungry buildings and trust me most of them are obscene, will be around for a long time causing their occupants pain and the world to expire faster, needlessly burning energy until they are refitted or rebuilt. Do everyone a favor, do the world a favor and go out of your way to insist five or six star energy compliance ( ) for any new building, especially by councils who can lead by example and large corporate ventures, who use the most energy.

    Lets do this!

  2. For the plugged in West, this is exactly the sort of do-it-yourself project that can spawn a celebration of changes and commitment essential to transitional culture. Thank you for publishing it.

    I’ve intended to link to your site (from Now I shall!

  3. Hang on… what about the (quite numerous) parts of the world where water is extremely scarce…? Will they want to use it to power a refrigerator?

  4. my guess is this is only really feasible on a small scale, (i.e., not to effectively cool entire rooms!) because as the size of the container increases, the surface area to volume ratio decreases. the ultimate effect is less loss of heat per unit of time in relation to the volume of the area being cooled.

    i could also be completely wrong, but if not, there’s nothing wrong with small scale!

    another thing i’m interested in: what is the relationship between cooling effectiveness and environment? In other words, where will this type of refrigerator work? Only in hot tropical or subtropical desert-type (arid) areas? Or will it work in temperate climates, too? If so, during what months of the year?

  5. Good article, remember though that the whole idea of a ‘carbon footprint’ is a terrible and ridiculous joke that has gone on too far.
    Carbon is a life giving gas and is NOT driving climate change. contary to politically motivated proaganda man made global warming is a fraud – see “The Great Global Warming Swindle”.

    1. Carbon and water are necessary to sustain life. Too much water and you get floods destroying whole cities. Producing too much carbon and destroying vegetation that recycles that carbon, gives you a planet that was in a slow cooling cycle to one that is being devastatingly affected by climate change. Super storms, log periods of drought, floods, ice caps melting, people staring and mass migration are becoming the norm. You can hide your head in political rhetoric all you want but the fact is this world as we know it is reacting to the callous way we treat it.


    it’s all there. the conclusions, the methodology. the money trails. what exactly about the scientific methodologies they use to assess the anthropogenic factors contributing to climate change do you disagree with?

    hate to break the news to you, dude, but you’re the one getting “swindled” if you’re believing the propaganda in that hack film. given the amount of money interest and power behind these efforts to debunk and dismiss anthropogenic climate change, i’m honestly surprised that the results have been so pathetic.

    ps “remember, though…” are you freaking kidding me?

    “oh, that’s RIGHT, i completely forgot for a moment that anthropogenic climate change is a HOAX. thank you so much for that reminder. i’m just soooo forgetful about these types of things sometimes.”

    is it really that easy for you to be a patronizing douche? or is it hard work?

  7. The Great Global Warming Swindle, a film that exposes the so called “consensus” of scientists as bogus is a “hack film”? Oh really?

    So I suppose “An Inconvenient Truth” from failed politician turned self-appointed global warming cult leader Al Gore is reliable and should be treated as gospel then, right?
    After all politicans are such an honest bunch of folks arent they?

    If there is money being made – and they certainly is – it is for those that suspend reason, logic, and independent scientific evidence and subscribe to the pro-anthropogenic(man-made)cult, whether it be for climate change scientists or for compliant journalists, who endless remind us to feel guilty of our “carbon footprint”. So plenty of money for those that go with the flow.
    Especially from the IPCC. The IpCC is a UN apointed body and is therefore obvious politically motivated and driven and huge amounts of money is poured into promoting this bogus theory.

    The fact is the entire solar system has been gradually heating up due to solar activity over the last century. It is not a problem solely happening on earth, therefore it is obviouslly not a man made problem and part of a bigger solar system wide issue.

    Try explaining this to the modern day end of the world end is night doomsayers.

    Is it not pathetic to trick people to get a list of scientists on file then? The fact is the cat is out of the bag, many scientists are now speaking out (some of which were man made global warming advocates and have back tracked)that this C02 = global warming theory is fundementally wrong – despite the intimidation to go along with UN sponsored bullshit.

    In fact there are far more scientists now who question this fraudelent science than there are IPCC “scientists” which is a fraudulent document (If you watch the film some of the scientists on the list asked to be removed from the list but they refused).

    Why are we being conned into believing this?
    so goverments can drastically destroy our quality of life in the form of punitive carbon taxes.

  8. Also worth seeing is “Global Warming or Global Governance” also on google video. Demonstrates the political reasons for instilling this insidious propaganda.

    This is no doubt another “hack film”.
    A “hack film” is a lovely all encompassing term and strategy to dismiss anybody who dares to counter official propaganda with sound scientific experiments (which is of course a big part of what science is about) so that you don’t need to get into troubling data that might challenge a viewpoint that you may have invested a strong emotional attachment too.

  9. In permaculture design we concentrate on links to constants in the universe and evaporation cools and condensation warms. Good design starts with good basic main frame themes which then iterate into complexity from there.

  10. Ethan, Ryan may well be right. Anthropogenic Global Warming is beginning to look like a huge and sinister confidence trick.

    Watch the video before you comment.

    …and please don’t descend into personal abuse of anyone, just because they disagree with you. When you lose your temper, you lose your argument.

  11. Citing “an inconvenient truth” is nothing but a red herring. i’ve never even seen the movie, and it’s not relevant to this discussion. I will simply ignore your patronizing attitudes (which, yes, I will continue to mock if you continue to act that way) and restate my original, unanswered question:

    what exactly about the scientific methodologies they use to assess the anthropogenic factors contributing to climate change do you disagree with?

    telling me to “watch a movie” that has long been dismantled due to being completely misleading and disingenuous — including both abuse of interviewees as well as scientific data, and using industry-funded research and scientists — isn’t really an effective form of answering that question.

    it’s really ironic that you spout off all this crap about int’l gov’t conspiracies and you don’t look at the matrix of power and control that already exists between governments and wealthy, extremely powerful industry interests. that’s not skepticism — it’s selective gullibility. millions and even billions of industry dollars [from basically a few rich white guys] which are behind the crap you keep trying to assert as “counter-evidence” that anthropogenic global warming is bunk.

    so, start ignoring the propaganda and start participating directly in the discussion about the scientific data, methodologies and techniques.

  12. as a small tag note: global warming isn’t “the end of the world.” but denying it is irresponsible and will simply make the fundamentals of life — such as plentiful access to clean drinking water, healthy food, and stable shelter — much more difficult to attain for all but the world’s wealthiest few.

  13. This is wonderful for hoy dry climates-not so great for hot humid climates-mold and bacteria problems plus evaporation would not happen quickly enough to get all the cooling benifits. In humid climates you can dig deep in the earth 3-4ft or more to take advantage of the earths naturally cool depths of if you have cold creek or spring in the shade you can submerge a waterproof cooler 3/4 up- this also works great.

  14. Ethan and Ryan: whether you believe in global warming or not, the truth of the matter is that the world population and its need for natural resources has drastically increased in the past century. However, the natural resources available haven’t increased, which means that with increased demand, those resources must have decreased. Which means that we are putting incredible strain on the environment. I’m sorry Ryan, but as this continues it won’t just be the government that’s ‘drastically destroying our quality of life’.

    I don’t know if you guys are from Australia or not, but do you think its a hoax that Melbourne’s just had the driest spring on record? Or that the reservoirs are drastically low going into summer? Yes, we’ve always had drought cycles, but like I said there’s much more demand now than ever before because of our lifestyles and population size. Let’s concentrate on what we really can do – live in a way that has as little impact on the environment as possible; which is the point of a permaculture forum, isn’t it?

    I’m so glad to see that people in Africa are making changes and being forward thinking in ways that us westerners struggle with. Maybe we can use these pots for our fresh fruit and veg, which might mean that we only need a small fridge for the rest of our food. I’m sure we can use rainwater or water caught in our shower to keep the pots moist rather than fresh tap water.

  15. Very interesting concept, too bad it will not work very well in humid Ohio. Some food for though… if you could sinking the copper coils on the back of a fridge 3-4ft into the ground, wouldn’t that conserve energy using geothermal properties?

    Man-made global warming is crap, Al Gores film was criminally convicted (in England) to contain 9 errors. Increasing CO2 is a product of increasing temperature not the other way around like Al would have you believe. He is just trying to tax the ‘life cycle’ in which CO2 is essential to (yes plants need CO2 to live and so do we!). However I do disagree with strip mining, oil spills and the like and think we need to put some deep consideration into this, but I’ll be damned if our solution is to hand over all the power to a panel of bureaucrat and ‘experts’. It is all of our responsibility to educate ourselves and participate in government.

  16. We are in Morocco and this sounds perfect as it is hot and dry out here. Will the fridge pot be cooler if left in the sun? I realise that you would have to add more water but if you wanted to keep more unstable products such as meat / fish etc?
    Cant wait to try it out

  17. Re fridge
    I have been using two large rectangular bisque fired clay pots for about two years now as a fridge – pretty similar to the one described. We can get up to 40 degrees centigrade here in the Klein Karoo South Africa. I am very happy with its performance, and am also going to be building a walk-in evaporation cool room. So if anyone out there has designs, it would be great to see them.
    I find it is better to leave the clay fridge in the shade – the cool side of the house is good, and somewhere where a breeze can move over it. A thick wet towel over it also helps!

  18. You guys are all arguing about, and comparing concepts from different eras and with differing circumstance. We all went through phases of supposed raising of living standard from the coolgardie safe to the modern freezer. Where is the dream of Frank Lloyd Wright of mile high sky scrapers set a mile apart to conserve the park and farming land? You forget one thing-does the feral human being have the right to take anything on the planet, at the expense of any other form of life, to superficially improve his own wellbeing? What we do today is only justifiable because we have to do it en masse, like a terrified pack of vermin who believe that the rest of our species will overrun us if we can’t get ’em first by overpopulating our bit of the planet first and then taking theirs off them as well!

  19. i wish there was more discussion on applying this and less on why we need to- i really need to find out some info on this pot fridge. ive been on the internet all night looking for information and all im getting in forums is enviromental and poltical debates.

    can we stop for one second arguing about who is holier and more righteous and who is evil and wrong and when the world will end and who is to blame and actually get something done please?

    does ANYONE know the specific temperature and humidity levels that this thing works on??? what is the scale of these that itll work in?

    i need to know if i can make a fake enviroment for one to get it to work in my muggy humid area. i want to know if its possible for me to create my own hot and dry box for this thing. but i have to know if its possible to do. i need actual temps and humidity levels. i cant find them anywhere. if anyone can help me i would appreciate it.

  20. Melissa
    I totally agree with you. I was astonished to see this thread degenerate into a not very well informed argument about MGW.
    I am intrigued by the concept of the cooler. Tomorrow I’m going to buy a set of those pots within pots that you see at all garden centres and experiment for myself. Not sure how applicable it might be here in the UK, but it is actually warm and sunny for a change so a good time to try!

  21. Melissa, Marianne, i think those are incredibly important questions. thank you for asking them! that’s the thing about privilege (racial, economic, whatever): we can sit back and question whether we should take action, and why.

    other people aren’t so fortunate. it’s about power. the islanders whose nations are disappearing underwater can’t afford such masturbatory and academic talk about hoaxes. it’s here now and the world’s historically vulnerable populations are bearing the brunt of it.

    it is all a familiar narrative: the people most responsible for producing problems or making life more difficult for others creating whatever little excuses we can to avoid taking responsibility and action.

    frankly, i don’t care whether privileged middle-upper class white people from the global north think global warming is a hoax as long as they are taking steps to reduce their carbon footprint… as Furgutt pointed out:

    “What we do today is only justifiable because we have to do it en masse, like a terrified pack of vermin who believe that the rest of our species will overrun us if we can’t get ‘em first by overpopulating our bit of the planet first and then taking theirs off them as well!”

    so here’s to an increase of localized self-reliance and the end of global economic slavery and ecological destruction at the hands of privileged Northern twits just because we want our latest iPhone or 3D TV.

    so just to echo some important questions again:
    “where will this type of refrigerator work? Only in hot tropical or subtropical desert-type (arid) areas? Or will it work in temperate climates, too? If so, during what months of the year?” -me (US)

    “Will the fridge pot be cooler if left in the sun?”-anders (Morocco)
    (someone said no, better in shade)

    “does ANYONE know the specific temperature and humidity levels that this thing works on??? what is the scale of these that itll work in?” -melissa

    in my area, there can be sometimes drastic swings in humidity during the summer, which means i may need to find another means of going fridge-less.

  22. Marianne, and anyone else interested in actually just talking about the pot in a pot fridge,

    Since i couldnt find anyone talking about the specifics of the pot in a pot system i looked up the humidity and temp of the places it works in and i guess ill just have to try and stay in that range. In Sudan it looks like its usualy 20-30 percent humidity and 80-100 degrees. here in Indiana (US) during summer it 80-100 degrees but with 80% humidity. So building a dry box for it might be a challenge for me- i dont use an air conditing or dehudifier in my apartment so its bery humid in here.

    My rough idea- That i have no clue if it will work- and would love some feedback on- is to build an airtight box to incase the pot in a pot.(perhaps an old fridge) it would be a tall roomy box- with enough space to allow the evaporation process to occur. with humidity and temp gauges. Then i will put little battery operated fans in the bottom (with rechargeable batteries that i will charge with my battery solar charger) – so that it will have good air flow. The i will line the box with bags of cheap and easy to find Calcium Chloride- which is a serious natural dehumidifier. the bags will pull the moisture out of the air and drip into collecting pans at the bottom of the box that i will empty when i water the sand or go in to to get food.

    the calcium chloride turns to mush when its taken all it can and has to be heated to get rid of the collected moisture and make it reusable- which i will do (in theory) with a solar cooker (ive heard this works). i will have “batches” in rotation so im never waiting for fresh chloride- so that it will just be a matter of switching things out- perhaps daily. But i dont mind pouring out a pan of water, switching a few bags, and watering sand on a daily basis if it means offgrid refridgeration in my apartment. to me thats well worth it. and even seems fun to me.

    My concern is that there will just be too much water in the box though. to actually keep the air inside dry.

    people make dry boxes with bags of calcium chloride all the time- and they work- but they arent continuously pouring water into the box.

    my other concern is if the whole system will make the entire box too cool- thus haulting the evaporation process- and haulting the cooling process….or will it cntiunously flux between cooling down and heating up and never really do anything at all.

    My other question that i would love to fnd the answer to is how the pot in pot system works at night- when the night air cools- im sure the Sudan nights are still hot- but does the temp change effect the system and how.

    because sometimes we get a cooling rain come through and everything will drop down to about 70% and i have no idea how that will effect my little set up.

    i am not a scientist or engineer or have any experience in these kinds of things- just a really strong desire to make it work wit hwhatever tidbits of info i can find on the web. so any help at all in this would be so very appreciated.


  23. Melissa, Ethan
    I really appreciate your comments and questions. There is obviously a lot of careful observation and measurement involved which I don’t have time to do just now with other ongoing projects. I thought I would just take pot luck (sorry about the pun!) and see what happens. If I find anything interesting or I become more involved, I will post it here

  24. for me, this brings up a larger question of “appropriate technology”

    the technology is secondary to the underlying purpose: food preservation.

    evaporative coolers seem to operate on the same principle (amiright?), and there’s more information about their place-based effectiveness which might roughly translate to this technology:

    it’s all relative: i think this technology is definitely less effective in my area (Willamette Valley) than it is, for example, in the high desert of Eastern Oregon. that doesn’t mean it’s not useful to me, just that i probably shouldn’t rely on it as a main form of food preservation…(?) so maybe that translates into me having one cooling pot instead of four, and relying more heavily on other food preservation technologies or techniques (fermentation!!).

    i could be way off base — maybe it’s really effective in my area. dunno.

    it never ceases to boggle my mind how our legacy of colonialism has stripped us of SO MUCH place-based cultural knowledge…both in terms of the uprooted placelessness of white/modern people and the oppression and genocide of native populations (and the marginalization or disappearance of their knowledge). we have so much rebuilding work to do around food culture!

    sometimes i think we are reinventing the wheel, but we’ve changed our environment/surrounding ecosystems so drastically that i also wonder how much of the native knowledge is still immediately relevant. e.g., so many new species and a decimated salmon population.

  25. The Pot! all to much talk! just do it=simple if it works ok if not what harm, I am about to relocate to a tropical southseas island with only solar,water tanks etc summer all year round. so will definatly give it a go My experience being an ex chef know food endurance. brilliant idea, yep back to basics for anyone who can let go of their phone ,Tv. car,& supermarket, I know us Aussies can!

  26. Does anyone know approximately what temperature range can be expected? I’d love to test this for myself but we won’t be anywhere near the proper temperature for the next few months, and I’m very very curious.

  27. Not to put a damper on all the glowing and thrilled comments, but cooling with water evaporation has been around for a long time. Some have even tried to tie it to HVAC air conditioning to reduce energy use.

    Evaporation has not proven to be a boon in civilized society. While it may be wonderful in the desert (where evaporation would be rapid, creating the greatest cooling effect) or wilderness, the constant wetness in less desolate areas will bring a host of other problems, including toxic mold.

    The notion that this could reduce our current usage by 90% is Pollyanna-ish at best.

    But, the idea is great for survivalists who find themselves in a desolate location. And, remember the water does not have to be potable as it does not make contact with your edibles.

  28. in certain parts of the USA collecting water in barrels, is illegal. And you have to pay the electric companies ‘fees’ if you use even one electric alternative device, unless they cant provide electricity (such as during a storm or other natural ,or unnatural occurance)

Leave a Reply

Your email address will not be published. Required fields are marked *

Related Articles

Back to top button