Indian Innovation Converts Sunlight To Heat With Record Efficiency

By Outlook Planet Desk November 13, 2023

New 'marigold-like' material unleashes solar-thermal potential, paving the way for sustainable heating solutions and carbon emission reductions

Indian Innovation Converts Sunlight To Heat With Record Efficiency
The solar-thermal energy market in India has immense potential in high-altitude regions like Ladakh and Himachal Pradesh, graced by sunshine for most of the year. Shutterstock

In a significant breakthrough, Indian scientists have unveiled a new material that could revolutionise solar-thermal energy conversion. This innovative material, featuring carbon nano-structures resembling marigold flowers, has set a new standard for effectively utilising solar power and converting it into heat energy. The discovery is expected to impact the field of renewable energy significantly. 

The solar-thermal energy market in India has immense potential in high-altitude regions like Ladakh and Himachal Pradesh, graced by sunshine for most of the year. This development is a significant milestone towards achieving net-zero carbon emissions and can potentially revolutionise the solar-thermal energy industry in India. 

For centuries, humans have relied heavily on fossil fuels to meet their thermal energy demands, which has resulted in negative environmental impacts such as greenhouse gas emissions and biodiversity loss. However, there is now a growing emphasis on harnessing the sun's direct energy and converting it into thermal energy.

Despite these efforts, the Ministry of Science and Technology has reported that only a small fraction of the sun's immense thermal energy potential has been successfully utilised so far. 

The Indian Institute of Technology (IIT) has developed a game-changing material called nanostructured hard-carbon florets (NCF) that has broken all previous records in solar-thermal conversion efficiency, achieving an astounding 87%. This achievement marks a significant leap forward in the pursuit of efficient solar-thermal conversion technology. 

NCFs have the ability to absorb over 97% of the ultraviolet, visible, and infrared components of sunlight and convert them into thermal energy. This thermal energy can be effectively transferred to air or water for practical purposes. Studies have shown that NCFs can raise the temperature of the surrounding air to 60 degrees Celsius, providing smoke-free solutions for space heating.

This advancement is particularly significant for... (the rest of the text is missing; please provide it) regions with cold climates and abundant sunshine, such as Leh and Ladakh, where Prof. C. Subramaniam from IIT highlights its significance. 

While solar thermal converters, like those used in solar water heaters, are employed worldwide, most are costly, bulky, and potentially harmful to the environment. Conventional coatings and materials for solar-thermal conversion are based on chromium or nickel films.

While anodized chromium is a heavy metal and toxic to the environment, chromium and nickel films exhibit solar-thermal conversion efficiencies ranging between 60 and 70 percent. In contrast, NCFs are composed mainly of carbon, making them cost-effective, environmentally sustainable, and user-friendly. 

Apart from their remarkable efficiency in converting sunlight into heat, nanocellulose films (NCFs) offer another advantage: ease of processing. The materials required for their production are easily available, and the production technique is easily scalable, which ensures cost-effective large-scale manufacturing. Once manufactured, NCFs can be effortlessly spray-painted onto almost any surface, similar to powder coating.

This reduces the cost of application and maintenance and makes it a user-friendly option for various industrial and commercial applications. 

Furthermore, researchers have demonstrated that copper tubes coated with NCFs can heat circulated air to over 70 degrees Celsius, offering additional heating possibilities. They have also achieved an unprecedented efficiency of 186 percent in converting water into vapour for purification, marking a remarkable advancement in this domain. 

The introduction of NCFs promises to usher in a new era of efficient and sustainable solar-thermal energy conversion, opening doors to cleaner, greener heating solutions and significantly reducing carbon emissions.