Ideas wanted: Environmentally-friendly cold storage with fast pay-back period

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Filed under: Development 2.0 Environment Poverty

Daniele Gelz and Stephan Schmitt-Degenhardt

During our work with small-scale entrepreneurs and farmers, we keep coming across the problem of cold storage. Finding good solutions for cold storage can have a tremendous positive impact on communities. For example, with appropriate cold storage fruit will no longer waste away quickly in the heat, or vegetables can be stored so that they can be sold when prices are higher.

The main challenges with cold storage in countries in the Commonwealth of Independent States and the Western Balkans are the initial cost of investment, operating costs, and reliable access to energy.

We want to identify solutions that address all three challenges. Despite the higher investment cost, we are currently looking into cooling units that use heat pumps, as these can be used (with some alterations) for cooling in summer and heating in winter, thus improving the operating costs.

However, the required temperature for cold storage is zero to five degrees Celsius, which heat pumps cannot usually achieve; customized and affordable cooling units would have to be designed.

Do you have any suggestions for cooling systems that are:

1. Capable of cooling to zero degrees Celsius

2. Affordable (small initial investment, or systems which can start small and be expanded)

3. Viable (low operating cost, low maintenance)

4. Reliable (low dependence on outside energy resources)

5. Environmentally friendly

We’d like to hear ideas about already tested systems or any new ideas too.

  • Emilio Valli

    many small farmers in Uzbekistan construct and use
    no-energy cold stores based on evaporative cooling.  capable to cool to a temperature of +1c.These suffer higher loss
    rates than refrigerated stores, but this is compensated by very low operating
    costs. Extending use of those stores and improving their construction and
    operations would offer greater numbers of farmers the opportunity to achieve
    the price gains available from storage. And because they are affordable by
    small farmers (including dehkans and backyard farmers), the benefits are likely
    to accrue to the poorer sections of the community. A possible size benefit is
    the encouragement that this could give to voluntary cooperation as a vehicle
    for comparatively expensive farm-level investments.

     

    • Stephan Schmitt-Degenhardt

      Good to hear from you, Emilio, and thanks a lot for your replies. Did I understand your first response correctly that the storage described is for use in winter time? If so, then it does not help us too much. But evaporative cooling is for drier climates a brilliant idea, which we have completely forgotten. Do you have some information on how those evaporative cooling devices are constructed, especially since they are no-power? How could we maybe cooperate to identify the improvements you were referring to?
      Many greetings, Stephan

  • Emilio Valli


     

     

                People in Fergana Valley
    from the old times use traditional storehouses for fruit and vegetables storage
    in winter time.

    Usually
    people store:

    -        
    fruits: grapes, apples, pears, pomegranates, quince,
    persimmons;

    -        
    vegetables: potatoes, onions, peppers and green
    tomatoes.

     

    These
    storehouses are constructed in traditional ways and using traditional local raw
    materials. The main construction is a dwelling with enclosing walls, a floor,
    windows and a roof. Walls and ceiling are covered with clay mixture (water +
    clay + hay (from wheat)). This mixture gives insulation effect.

     

    Sun
    rays should not get the windows and doors of the storehouse. That is why in
    Fergana these storehouses are constructed with the windows and doors on the northern
    direction of the abode.

     

                Dimensions are varied based on the required
    capacity of the storehouse. Dimensions of the average storehouse for 5 tons of
    grapes are as following:

     

    Length – 6 meters;

    Width – 4 meters;

    Height – 3 meters.

     

                This typical storehouse has two
    windows and one door.

     

     

  • Emilio Valli

    Dear Stephan,

     

    Great to hear from you too. Yes, unfortunately
    the storage described is for use in winter time, hence of limited help. I
    attach some additional information on how these evaporative cooling devices are
    constructed.  I think in order to
    identify the improvement we need to gather local stakeholders, notably Rural
    Development Centers in the Fergana region and Chamber of Commerce.

     

    Kind regards,

     

    Emilio

     

  • M P

    There is one more solution not based on evaporative cooling:

    cheap, easy-to-do, environment-friendly, widely available, with a potencial for re-cycling materials use, based on renevable resources, energy-free and forgotten.

    In Central Asia and Balkans winters are very cold. The point is to accumulate this cold and keep it until the end of the summer or at least till autmn. Here is some idea on how to do this and how was it done even 1700 BC:

    http://en.wikipedia.org/wiki/Ice_house_%28building%29
    (please read it)

    and

    https://picasaweb.google.com/106734143291221809916/Iran1909201020102010#5533477860140588642

    https://picasaweb.google.com/106734143291221809916/Iran1909201020102010#5531353751805009314 https://picasaweb.google.com/106734143291221809916/Iran1909201020102010#5533477831004865282

    In 21st century there is a lot of possibilities, especially in insolation technology to make the idea much more efficient. Here is my rough plan:
    1) build a chamber which should be cooled out of bricks/use a small shed?. No windows,
    2) entrance from north in a form of a vestibule – it will not allow hot air to get straight into the cold room
    3) insulate the building from outside from water/humidity
    4) floor should also be insulated. Floor-insulation should be connected with outer water-resistant insulation
    5) cover it all from outside with something hard (recycled plastic, metal sheets or simply wooden desks (at least they will rotten after a few yeats) in order to protect the insulation from destroying. Even a second thinner brick layer can be given
    6) cover the building with ice from outside. Somebody has to calculate it/or check in real but at least 50 cm seems to be resonable?
    7) cover the ice with 20 or more cm of styrofoam. It would be something like a second building on the former one. The construction should be done out of wood and styrofoam in a form of elements in sizes like 2x3m which can be easily removable in autmn when new ice will have to be gatherd during the winter
    8) cover the styrofoam insulation with white water-resistant foil to reflect sun rays
    9) shade the building with some material on 4 high sticks or build all the construction in a shade of a house/trees

    Now an engineer is needed to make sure if it can be used for a cold-room of for example size 5x6x2m. How much cold can be stored is such a “fridge”. If there was a chamber 5m wide, 6 long and 2m tall and covered with 0,5m of ice it would give 45 m3 of ice – it is quite a lot.

    Finally, my grandfather told me that before WWII they used such a fridge (Poland) for storing of milk during summer. It was even more simple construction:
    1) small chamber built of ice-bricks (igloo)
    2) covered with lots of earth
    3) in shade behind a house

    Michał Podolski