Kurukshetra, March 22 (BP Bureau) ,
Dr. Chandrasekhar M, Assistant Professor in the Department of Mechanical Engineering, National Institute of Technology Kurukshetra, has developed a natural evaporation cooling system using Kulhar made of sand. The technology was showcased and won the Gujarat Energy Innovation Prize 2024 at Indian Institute of Management Ahmedabad on 30 January 2025. The technology was presented to distinguished guests including Shri Jagdish Vishwkarma, Minister, Khadi, Rural and Cottage Industries, Government of Gujarat, Prof. Padmashri Anil Kumar Gupta, National Innovation Foundation, Government of India, Founder of Honey Bee Network and Gujarat Grassroot Innovation Augmentation Network, and other esteemed guests, researchers, industrialists and innovators participating in this innovation competition from India and abroad.
Dr. Chandrasekhar mentioned that energy is the basic need for the development of a nation, which motivates them to develop technology to generate more energy using solar energy, which is clean, renewable and sustainable. This helps to reduce carbon emissions and conserve the ecology. Dr. Chandrasekhar M has received 11 out of 16 patents, has 2 sponsored research projects, has guided 4 Ph.D., 24 M.Tech students and has 19 international journal publications on solar energy. He has also developed solar technologies for space heating, water heating, solar oven and cooking.
Problems in Solar Energy Generation:
Increasing temperature of solar panel leads to decrease in energy production (Temperature coefficient of energy: -0.45%/°C), and thermal decay occurs when the panel temperature rises above 45°C. Higher cell temperatures lead to overheating and hotspots, thermal stress, expansion and contraction due to daily temperature variations, and may cause glass panels to break, leading to quicker e-waste and reduced energy production.
Solution:
The solar technology developed at NIT Kurukshetra increases daily energy production by 10%, and almost doubles energy production in hot and dry weather. The cell temperature can be reduced by up to 20°C by clay kulhar technology, which outperforms methods like aluminium fin cooling, water spraying, phase change materials and saves water. It avoids overheating and hotspots, which can cause e-waste, thermal stress and damage due to daily temperature fluctuations. This innovation also doubles the lifespan of the solar cell by up to 50 years. The technology is scalable, repeatable and sustainable, using clay kulhar made of sand and mixed with only sand. The cooling technology costs ₹3/W and is eco-friendly, improving efficiency, lifespan and durability.
The clay devices, made of traditional handmade pottery, are in the shape of plates, boxes and cups and are filled with water. These devices are attached to the back of the PV panels, as shown in the figure, and are connected to the water tank through a piping system and gravity flow. They provide cooling through natural evaporation of water from the micro-pores of the sand, and require minimal water and no energy consumption.
Anusandhan National Research Foundation, Government of India, has sanctioned a budget of ₹42+ lakh to develop a large-scale pilot plant project of up to 20 kW from 17 March 2025. The technology also provides employment opportunities for potters across India. Experimental study of clay cooling technology for large scale solar power plants (up to 20 kW) builds confidence in the solar industry, and helps in adoption of the technology at GW level. Our technology creates significant business opportunities for 500 GW at ₹3/W, worth ₹1.5 lakh crore for potters in rural India, contributing to the 500 GW solar power target by 2030. International Energy Agency (IEA) has predicted 4,000 GW of new solar capacity worldwide by 2030. 4,000 GW at ₹3/W is worth ₹12 lakh crore, creating a market for Indian potters to export kulharkas globally.
The technology is scalable from home installations to large GW solar parks and can be replicated in various hot and dry climate regions, such as Rajasthan, Maharashtra, Tamil Nadu, Andhra Pradesh (Rayalaseema region), Madhya Pradesh and Gujarat, where solar panel temperatures often go above 80°C. It is also sustainable, as the earthenware devices are made of sand, which can be composted at the end of their lifespan.
The technology has also been nominated for innovation competitions such as Dare to Dream 5.0, organised by Defence Research and Development Organisation, Carbon Zero Challenge at IIT Madras, and internationally, such as Elsevier-International Solar Energy Society (ISES) Renewable Transformation Challenge in Brazil and Global Energy 2025 in Moscow, Russia. These competitions are meant to showcase the technology globally.
