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THERMAL STORAGE BASED COLD STORAGE SOLUTION

India is the world’s largest producer of fresh fruits and vegetables, milk, spices, select fresh meat, dry

fruits, agriculture-based textile raw materials, roots and tuber crops and eggs. India exported 600,000

metric tons of fish products to nearly half of all the world’s countries. There is a huge challenge of

preserving and distributing fresh produce especially vegetables, milk and fruits across the country giving

rise to high inflation as also spoilage / wastage of food. Also processed foods contribute to only 4% of our

total consumption while it is to the tune of 60-70% in developed countries.

In order to catch up with the rate of processing and reduce the product spoilage, it is imperative for India

to modernize its cold supply chain infrastructure which has been hugely hampered by high costs and poor

power infrastructure issues.

Conventional cold chain technology of concurrent cooling using vapor compression and vapor absorption

require a continuous source of power to maintain the temperatures in a cold chamber. Therefore, for a

stationary cold storage, you need a continuous power supply and several hours of Diesel generator usage

to make up for the frequent black outs. In a refrigerated transport vehicle, you need a continuous diesel

engine input to run the compressor. Putting in perspective, a small 8 feet truck uses almost 1800 liters of

diesel and north of Rs. 1 lac every year for cooling the goods only.

A new alternative to the conventional systems is latent energy storage based cooling system recently

introduced in the Indian market. Latent storage simplified is like an ice pack that can freeze in your

refrigerator to become ice and then melts once used. The basic principle is that when water changes into

ice, it stores more than 20 times the energy than equivalent amount of water at 0oC.

These systems, based on the design, can enable one to maintain the temperature of the cold storage for

upto 24-36 hours without any additional power input. These systems either use modular heat exchangers

called eutectic plates or small centralized storage tanks inside which a special chemical called “Phase

Change Material” is frozen or melted. Once frozen, the heat exchanger enables regular melting of the

material to maintain a certain temperature range in the system.

For example, in a transport refrigeration application, the system contains an internal heat exchanger with

the phase change material and an outdoor unit with an electric run compressor. When the vehicle is

waiting at a hub, it can be connected to a power source which freezes the internal heat exchanger over 4-5

hours. Once frozen, it can travel 24 hours without any diesel consumption on refrigeration. Taking the

example of the same 8 feet truck, the annual operating cost goes down from Rs. 1 lac to Rs. 35,000 (by

65%). Given that there are no moving parts during travel, the maintenance costs also go down

tremendously.

Such a technology is extremely well suited to conditions in India where continuous power is a

tremendous problem. This can cater from a small kirana shop looking to store milk and ice-cream to a

logistics operator delivering chilled or frozen produce to the market. It has been applied to small carts,

freeze boxes to 40 feet containers. There are also systems developed for its use in air conditioning

©Thermal Energy Service Solutions Pvt. Ltd.

systems at a small commercial level. With the right productization and positioning of this technology, it

can potentially change the way temperature controlled supply chain works in India.

ABOUT TESSOL

TESSOL is a venture funded start-up based out of Navi Mumbai commercializing Latent energy storage

technology for cold chain and air conditioning applications across India. Founded by alumni from IIT,

Harvard and Cornell, the company has a range of chilled, frozen and multi temperature storage solutions

for both stationary and transport cold storage. Currently operating mostly in the western region, the

company is rapidly growing its network of sales and service partners across the country.