Harnessing Solar energy, Options for India

It is clear that the CPSC is economically viable and can reduce the usage of fossil fuel. The solar steam
cooking system provides an eco-friendly solution to meet the energy demands of cooking in
community kitchens.
4. Solar Heat for Industrial Applications
The current application of solar energy for industrial process heat is negligible around the world.
However, the potential for this is large, both worldwide and in India. Industries account for about
40% of the total primary energy consumption. As of 2008, there were only ninety solar thermal
plants for process heat operating in the world. 24 There are currently just a few of these in India.
Moreover, each unit is customised for a specific application and location. Hence, there is less data on
the economics and energy savings from the use of solar thermal technology in industrial
applications.
Solar thermal solutions can abate the use of fossil fuel in low to medium temperature applications.
Since both FPCs and ETCs can only produce temperatures up to 85°C, 25 Scheffler or CPSC systems
can be used to produce higher temperatures required for industrial process heat. IIT Mumbai, in
collaboration with Clique Development, has successfully developed solar concentrators based on the
Fresnel paraboloid technology under the trademark ARUN. 26 Some of these installations are used
in the dairy industry (Latur and Bhilvadi in Maharashtra) and to generate steam for different
processes at the Heavy Water Board. Solar thermal technologies can be used in chemical processing
plants, textile industry and in paint shops for drying.
4.1. Application
The Latur Dairy Plant pasteurises 25,000 litres of milk per day. In the milk industry, thermal energy
is used for pasteurisation (60–85°C) and sterilisation (130–150°C) processes. Drying of milk
powder, with high constant energy required, is another important demand. During production, milk
and whey are spray-dried in huge towers with air that is heated from 60°C to 180°C.
The use of solar heat processing saves the plant about 75 kg of furnace oil a day. The energy saved
daily is about 840 kWh. 27 Even if only 1,000 milk cooperatives in India were to use solar energy to
offset some of their fossil fuel consumption in pasteurisation, about 269 million kWh of energy
consumption could be abated and 177 million kg of CO 2 could be abated annually for the lifetime of
the plant.
5. Solar Water Heating Systems
Solar water heating systems (SWHS) are generally composed of solar thermal collectors, a water
storage tank, interconnecting pipes and a fluid system to move the heat from the collector to the
tank. Globally, solar water heating is commercially viable, and is competing directly with
conventional water heating systems. China is undoubtedly the world leader in this – their annual
production in 2007 reached 40 million m 2 , accounting for two-thirds of global output that year. 28
Furthermore, China has the largest installed base of SWHS in the world with over 125 million m 2 and
one in ten families having adopted the technology.
In India, the current SWHS collector area stands at a more modest 3.53 million m 2 , 29 with 0.62
million m 2 of collector area added in 2009–10. Earlier, only FPCs were used in India, but ETCs have
been introduced in the market in the last few years. 30 The realisable techno-economic potential at
this stage has been estimated at 40 million m 2 . 31 Greentech estimated that the SWH market potential
Solar Thermal Applications CSTEP | Page 99