Solar panels generate electricity, but factories also use a great deal of energy as heat. Food processing, textiles, chemicals and other industries need hot water, drying and steam. Concentrated solar thermal technology brings sunlight directly into those processes.
Mirrors track the sun and focus sunlight onto a receiver, which heats water or another fluid. That heat can drive a turbine, which is concentrating solar electricity (CSP), or serve industrial uses such as food processing and chemical production (US Department of Energy). When the heat goes straight to a process, it is often called concentrated solar thermal (CST).
India has a real market for it. The Ministry of New and Renewable Energy estimates industrial CST potential at about 6.45 GWth, with dairy, food processing, textiles, paper, chemicals and pharmaceuticals among the best-suited sectors (MNRE). Indian standards already cover parabolic dish, Scheffler and parabolic trough concentrators.
Integration can begin with one specific duty: preheating boiler feedwater, supplying process heat or raising steam at the required conditions. Solar heat meets part of the demand while existing equipment covers the rest. For heat below about 100°C, simpler flat-plate or evacuated-tube collectors may be the better choice; concentrating collectors earn their place at steam temperatures.
Site selection matters. Concentrating collectors need strong direct sunlight, so cloud cover and seasons shape output; in much of India, the monsoon months will deliver noticeably less. Available space, pipe distances, cleaning needs and the factory's operating schedule also affect the business case.
Thermal storage can extend the hours when solar heat is useful. Its capacity and discharge rate set how much demand it can cover. Reliable production still needs a plan for long low-sun periods and equipment downtime.
The most useful comparison is the cost of heat delivered to the process at the required temperature and pressure. That figure should include the solar field, any storage, integration, maintenance and the backup energy still needed.
Solar thermal is one of several proven routes to industrial hot water, steam and drying (Australian Government). For suitable sites, it is a practical next step in decarbonisation: extend the solar strategy from the factory's electricity to its heat.