A new material called nanostructured hard-carbon florets (NCFs) developed at IIT Bombay, has achieved an unprecedented solar-thermal conversion efficiency of over 87 per cent. This material efficiently converts sunlight into thermal energy, making it suitable for practical applications such as heating air and water. It effectively absorbs over 97 per cent of sunlight's ultraviolet, visible, and infrared components, converting them into thermal energy. The resulting heat can be efficiently transferred to either air or water for practical applications. Research reveals that NCFs can raise the temperature of the surrounding air from room temperature to 60 degrees Celsius, providing smoke-free space-heating solutions.
According to Professor C Subramaniam of IIT Bombay's Department of Chemistry, "This is particularly relevant for heating spaces located in cold climatic conditions that receive abundant sunshine, such as Leh and Ladakh."
Solar thermal converters, like those found in solar water heaters, are already in use worldwide. The Ministry of New and Renewable Energy estimates that 2.5 per cent of Indian households, approximately 40 million, use solar water heaters. However, conventional solar heat absorbers are often costly, bulky, and environmentally harmful.
Dr Ananya Sah, the lead author of the NCF study, said, "Conventional coatings and materials for solar-thermal conversion are based on chromium (Cr) or nickel (Ni) films. While anodized chromium is a heavy metal and toxic to the environment, both Cr and Ni films exhibit solar-thermal conversion efficiencies ranging from 60 to 70 per cent. In fact, the best commercial ones in the market operate at 70 per cent solar-thermal conversion efficiencies."
The study, supported by the Swarna Jayanti Fellowship of the Department of Science and Technology in India, presents a sustainable solution to the global energy crisis and aids in the transition to eco-friendly energy sources, as stated in an official statement by IIT Bombay.
Professor Subramaniam expressed optimism, saying, "I strongly believe that NCF has the potential to revolutionize the solar-thermal energy market in India and pave the way for decarbonisation."
