Harnessing Solar energy, Options for India

Figure 19: Solar Dryer Installation at Sakthi Masala, Erode (left), and Leather Drier with Hot Air Ducts
at M.A. Khizar Hussain & Sons, Chennai (right)
(Source: http://www.assocham.org/3rdasia/presentations/p25-04-8/TECHNICAL_SESSION_2/DR_C_PALANIPPAN.pdf)
2.2. Applications
The fishing industry employs 14.66 million people in all. India’s 8,041 km of coastline and inland
waterways together annually contribute about 5,600 million kilograms of fish. Since fish is
perishable and spoils quickly, it must be chilled or dried in order to extend its shelf life. Currently in
India only 6% of fish is dried and cured. 13 Conservatively assuming that all of this is dried using solar
FPCs, this would imply that 336 million kg of fish could be dried hygienically, while also improving
its marketability. Also, 50.4 million m 2 of FPC area or, alternatively, 80.64 million kg of firewood,
would be required to dry this quantity of fish.
Fishing can be carried on for about ten months a year barring spawning season. The coastline
receives bountiful solar energy except for the monsoon months; hence, solar drying is possible for
most of the year. Small-scale drying of fish is generally done in the open under the sun, while largescale
commercial drying uses firewood as fuel. The state government of Kerala has set up
community-based fish drying units that are a hybrid of FPCs and firewood. Fisher people are
charged a nominal fee based on the weight of fish. Furthermore, subsidised hygienic plastic bags are
also provided to market the dried fish.
Given the large domestic and international market for dried fish, this is an application that should be
incentivised.
In the tea industry, the manufacturing process involves withering, processing (rolling/Cut-Tear-
Curl), fermentation, drying, sifting and packing. The three different forms of energy used in tea
manufacturing are electrical, thermal and human. More than 80% of the energy required is thermal
in order to remove moisture from the tea during withering and drying. 14 Normally, 1 kg of coal is
used to process 1 kg of tea. 15,16 With solar air heating, the potential savings are about 0.15 kg of coal
per kg of processed tea. 17,18 The Tea Board of India estimates total production to be 979 million kg as
of December 2009, with 75% coming from north India where solar energy is limited. If solar air
heating is assumed for 30% of the tea production in north India and 50% in south India, a a savings of
about 51.3 million kg of domestic coal is possible. The total energy saved will be about 225 million
kWh (with an equivalent CO 2 emission reduction of 225 million kg). b Thus, solar air heating systems
could play a considerable role in reducing the amounts of coal and firewood used. Table 25 gives an
overview of costs for solar heating installation in the tea industry.
a Tea estates in the north-eastern state of Assam do not have as many sunny days as the south Indian estates.
b Assuming CO 2 due to coal = 1 kg/kwh.
Solar Thermal Applications CSTEP | Page 94