The food choice expectations of people living in developed countries are made possible by affordable refrigeration systems across the entire food supply chain. Introducing similar systems for developing countries will be difficult and will require large amounts of energy. Avoiding refrigeration dependence is difficult when economic development depends on exporting food to more industrialized countries (FAO Policy Brief). Refrigerated storage can account for up to 10 percent of the total carbon footprint for some products when electricity inputs, the manufacturing of cooling equipment, and GHG emissions from lost refrigerants are taken into account (Cleland, 2010).
Active cooling depends on electricity supply. Further solutions are passive evaporative-cooling technologies and stand-alone solar chiller – once they become economically viable. According to Bundschuh and Chen improvements to technical elements and operation of modern refrigeration systems have the potential to reduce energy consumption by 15-40%.
In the post-harvest cycle cooling is particularly crucial in the stages of pre-cooling and cold storage.
According to the FAO, pre-cooling is “amongst the most efficient quality enhancements available” and is regarded “as one of the most value-adding activities in the horticultural chain”.
Pre-cooling refers to the rapid removal of field heat shortly after the harvest of a crop. Field heat can be defined as the difference in temperature between the temperature of the crop harvested and the optimal storage temperature of that product. Benefits of pre-cooling include:
- lowering the required workload of a cold storage since optimum storage temperature is reached more quickly
- restricting and minimizing respiratory activity, thereby conserving the weight of the produce, and enzymatic degradation of the produce harvested; thus preventing softening, water loss and wilting
- preventing microbial growth, such as bacteria and fungi thereby decreasing the rate of decaydecreasing rate of ethylene production and the impact on ethylene sensitive produce
- delaying chilling injuries for certain fruits
- increasing the daily intake into storage facilities which should not exceed 10% of its cooling capacity if produce is not pre-cooled
Cooling and cold storage are very energy intensive and expensive undertakings that require reliable electricity supply. This precondition is often not given and capital and running costs for farmers in developing countries are generally too high. Hence, unbroken cold chains and the use of appropriate cold storage facilities are generally not accessible for small-scale farmers.
Several low technology options are being presented that can operate in electricity scarce regions and are feasible for small-scale farming operations….Read more.
Clean Energy Solutions for Cooling
- ↑ FAO Policy Brief. The Case for Energy-Smart Food.
- ↑ Cleland D, 2010. Towards a sustainable cold chain, 1st International Cold Chain Conference, International Institute of Refrigeration, Cambridge, UK. March.