Cold storage: sustainable solutions for developing countries with hot climates

In developing countries close to the equator, the lack of adequate cold chain infrastructure leads to significant post-harvest losses, with farmers and retailers often unable to properly store perishable goods. 

 

As underlined by the authors of a paper (1) recently presented at the IIR International Congress of Refrigeration, in developing countries, the consequences of food losses are amplified by the economic importance of agriculture. Thus, the equivalent of 936 billion US dollars is lost each year due to food losses. In sub-Saharan Africa alone, food losses represent 40 to 50% of food production, or 4 billion US dollars lost each year. 

 

Added to the lack of structures is the unreliability and inadequacy of the electricity network in many developing countries, preventing the use of conventional vapour compression refrigeration technologies using electricity. Thus, in Sub-Saharan Africa, 65% of the population does not have access to electricity. Therefore, non-electric refrigeration technologies are options to consider for cold storage in these countries.

 

India is the world's second largest producer of fruits and vegetables after China. Agriculture represents more than 14% of GDP and employs around 44% of the population. Furthermore, 58% of rural households depend on agriculture as their main source of income. (2) 

 

In India, up to 40% of production is lost each year while cold storage is available for only 10% of perishable goods. This corresponds to a lack of cold storage infrastructure for 12.6 million tonnes of fruit and vegetables. Additionally, of the available cold storage, 85-90% is dedicated to potatoes, and around 95% of these are owned by the private sector, limiting access to farmers. 

 

The estimated economic value of post-harvest losses in India was around USD 15.2 billion in 2021, or around 0.5% of the country's GDP. 

 

If the cold storage shortage were to be met entirely by vapour compression systems, approximately 12 TWh of additional electricity generation would be required. This conservative estimate represents 0.5% of the national electricity supply; However, for some states in India – such as Bihar – which are large agricultural producers, this would imply an increase in their current electricity supply of up to 17%. Additionally, this increase in electricity generation would result in 8.7 million tonnes of CO2 emissions based on the current electricity generation mix. All this limits the applicability of electrically powered refrigeration systems. 

 

Evaporative cooling is an alternative technology that can limit electricity consumption and corresponding emissions. As evaporative cooling does not adapt well to humid climates, if we only take into account regions of India with a hot and dry climate such as Rajasthan, only around 25% of the surface area of India could be affected, or 15% of agricultural production. 

 

The authors point out, on the other hand, that if this shortage of cold stores were filled by thermally driven steam sorption systems, this would have a negligible impact on electricity production. Vapour sorption systems use thermal compression which is less efficient than mechanical compression. However, in India, 158 million tonnes of excess agricultural residues are generated every year and the biomass could be used to power sorption cooling systems with lower operating cost than vapour compression systems. 

 

India also has energy potential linked to solar energy. According to the authors, this theoretical potential amounts to an electricity production of around 500,000 TWh per year based on a photovoltaic conversion efficiency of 10%. Solar thermal energy can also be used directly in sorption cooling systems without conversion to electricity. 

 

In terms of environmental impact, a comparison of net carbon emissions indicates that biomass-powered steam sorption could save 5.3 million tonnes of carbon emissions compared to vapour compression, and even 1.3 million tonnes compared to evaporative cooling. 

 

Download the new guide on cold rooms in hot countries published by the IIF and Efficiency for Access (open access): https://iifiir.org/en/fridoc/walk-in-cold-rooms-a-practitioner-s-technical-guide-design-and-148065

Download individual 2023 IIR Congress papers (free for IIR standard and corporate members): https://iifiir.org/fr/fridoc?notice_search_form%5Bhasnt_documents%5D=true&notice_search_form%5Bparent_id%5D=147365  

Download 2023 IIR Congress proceedings: https://iifiir.org/en/fridoc/proceedings-of-the-26-lt-sup-gt-th-lt-sup-gt-iir-international-congress-of-147365  

 

Sources: 

Duffy A. M. et al, Assessment of cold chain options, critical needs, and emerging solutions in developing countries with warm climates. https://iifiir.org/fr/fridoc/evaluation-des-options-de-la-chaine-du-froid-des-besoins-critiques-et-147908  

Gupta P. et al, Refrigerated Transportation and Cold-chain Logistics in India – Current Status and Future Prospects. https://iifiir.org/fr/fridoc/le-transport-frigorifique-et-la-logistique-de-la-chaine-du-froid-en-147857