What is Concentrated Solar Thermal (CST)?

Manufacturers in industrial clusters such as Morbi and Ludhiana have begun exploring alternatives to natural gas and other fossil fuels as the ongoing geopolitical tensions in West Asia trigger volatility in global energy markets.

Experts suggest that concentrated solar thermal (CST) technology could become increasingly relevant as industries look for reliable and cost-effective energy sources.

What is Concentrated Solar Thermal (CST)?

Unlike photovoltaic systems, which convert sunlight directly into electricity using semiconductors, CST works by concentrating sunlight to produce heat.

• Concentrated Solar Power (CSP) technologies use mirrors to reflect and concentrate sunlight onto a receiver.
• The concentrated sunlight heats a high-temperature fluid such as water or molten salt, which can reach temperatures of up to 400°C.
• This thermal energy can then be used to generate electricity by driving turbines or for direct industrial heat applications.

Industrial Applications: The heat produced by CST systems can be used in several industrial processes, including: Water desalination, Enhanced oil recovery, Food processing, Chemical production, Mineral processing.

In the textile industry, processes such as scouring and bleaching typically require temperatures between 100°C and 180°C. Textile mills could install parabolic trough systems on factory premises or nearby land to generate pressurised steam directly from sunlight, reducing reliance on fossil fuels.

Potential in India: According to the Ministry of New and Renewable Energy, India has a CST potential of about 6.4 GW. However, adoption has remained relatively low so far. With natural gas prices reportedly tripling due to the West Asia conflict, the payback period for CST installations may reduce from the current seven years, making the technology more attractive for industries.

Plasma torches

High-temperature industries such as ceramics manufacturing are also exploring technologies like plasma torches.

• Plasma torches work by ionising gas into plasma, often referred to as the fourth state of matter.
• The resulting plasma can reach extremely high temperatures, sometimes exceeding those found on the surface of the Sun.
• These systems allow precise temperature control, preventing under- or over-heating during industrial processes.

Sources: TH, US Energy