Solar Thermal Processes Interview "Solar Thermal Processes hold Huge Potentials for India"
Solar Thermal Process Heat (STPH) as a form of solar energy can be utilised in many different sectors in industry and commerce. Besides the application of solar thermal processes for large scale hot water demand (up to 70°C), STPH with medium (up to 200°C) or high temperature ranges (over 250°C) can also be used economically in many industrial sectors like pulp & paper, pharmaceuticals, food processing, dairy and so on. Dr. Shireesh B. Kedare, Adjunct Professor, Department of Energy Science and Engineering, IIT-Bombay, talks to PROCESS India on the potential of STPH in Indian process industries…
PROCESS India: What is the application potential of STPH in Indian process industries?
Dr. Shireesh B. Kedare: The application potential is very large considering the recent developments that have some interesting features. The solar energy can go to the complete range of temperatures of 150 to 350 degree centigrade. This range practically covers all the required ranges in the industry.
Various working media can be handled like water, pressurised water, steam at low pressure with non-IBR system, steam at medium pressure with IBR approved system, hot oil or thermic fluid etc. It is also possible to design hot air system.
Thus, we feel that at least 30 per cent of the thermal energy requirements can be taken care of by solar concentrator systems. The solar system is integrated with the existing industrial thermal process in add-on mode.
Hence, the existing system is not disturbed; it can take over anytime the sun is not there as well as the process controls are typically kept untouched, and remain in governing position. Also, work is done and implemented in field for optimising the integration and sizing.
Environmental Benefits of Solar Thermal Processes
PROCESS India: To what extent can it benefit process industries from the environmental angle?
Dr. Kedare: The first thing is – as the solar systems do not emit any smoke or dust, it is absolutely clean. It does not emit CO2 or any unburnt particles or pollutants. It does not emit any heat, thus, saves global warming. Further, these are noiseless systems. Some of the technologies need ground space. But systems like – Arun Fresnel Paraboloid Dish (developed in collaboration with IIT Bombay) require minimum ground space, or can go on the roof, even if the roof is not flat.
What about the Monsoon? Speciality Solutions for Indian Customers
PROCESS India: Considering monsoon and other cloudy days, what is your comment on the commercial viability of this technology?
Dr. Kedare: Many parts of India have up to 250 to 325 good sunny days annually. In such cases, the project is viable. However, the integration is very important. Also, the system’s reliability,
ensuring that it is coming from a good professional group and good solar system efficiency are important factors. This helps in running the system even during low radiation levels.
PROCESS India: What kind of R&D work is being done on it in India?
Dr. Kedare: Through research, efficient and high temperature solar systems like – Arun Fresnel Paraboloid Dish have been developed, different testing methods have been developed, and integration optimisation methods also have been developed.
Lots of developmental issues related to reliability, system cost etc., are now being addressed through R&D. Good ground experience is being generated.
How Solar Thermal Processes Could Achieve the Breakthrough...
PROCESS India: How are you planning to disseminate and popularise this technology in India?
Dr. Kedare: We conduct training courses. Recently in May 2012, we organised one such programme in Mumbai to create awareness. This is being done by MNRE (Ministry of New and
Renewable Energy) as well as other institutes. Detailed training courses are also being planned for engineers in future.
PROCESS India: What is your message to the Indian process plant owners?
Dr. Kedare: My message is – solar energy can be used to deliver medium to high temperatures beyond the flat plate heaters or evacuated tubes. Lot of ground experience is being accumulated
by few of the companies. Systems are now more reliable and optimally designed. The economic benefits in the long-run are very high considering the fuel oil prices increasing at 14 to 15 per cent per year.