The Energy Science Department of IIT Bombay on Monday revealed on Monday a promising new take on conventional solar technology: coloured solar cells which can be integrated into buildings in window glass, façades, even roof shingles, making them an attractive choice for urban landscaping.
The invention consists of a nanophotonic coating named Selectively Modulated Aesthetic Reflector Technology or SMART. An IIT Bombay said, “The beauty of this invention is, just like mixing colours or lights to make different other colours, here the inventors have succeeded in mixing nanophotonic coatings to generate different colour appearance for solar modules.”
The most efficient technologies require placement on horizontal surfaces like rooftops, and are also limited in their colours: blue or black absorb the most light; other colours reflect more light, permitting less of it to reach the solar cells. This makes them less attractive to designers and architects. The Smart coating reflects only a selected wavelength of light, which gives it a coloured effect, while allowing the cell below to work with 60% to 80% efficiency. It can also be used on vertical areas of buildings, increasing the options for designers to integrate them into their projects.
Dr. Aldrin Antony and Anishkumar Soman, the inventors, feel that their technology could change the way we look at building architecture. Dr. Aldrin, who left his job in solar energy research and permanent residency in Europe to join the National Solar Energy Mission, told The Hindu, “India is a country where we love bright colours. That’s what I had in mind while working on our invention.” Another advantage their technology has its durability; Dr. Antony says it would guarantee 25 years of service for solar module. Mr. Soman, currently a doctoral student at the Electrical Engineering Department of University of Delaware said, “We wish to make solar cells customisable, attractive and irresistible to people, along with contributing to a greener planet. Imagine sparkling, appealing, beautifully coloured, customisable window shades and façades generating energy for you. Isn’t it cool?”
Conceding that their invention will not be able to gain mass use, as the coating will be expensive, Dr. Antony says, “So we are targeting people with aesthetic needs and higher middle class of society.”
The inventors have already filed for an Indian patent in 2015 and a PCT in 2017. They are currently being approached by glass manufacturing companies and wish to license their technology to local players instead of international ones to promote technology development within the country. Dr Antony hopes that they will get support from the government and media: “I feel our work has been in line with the government policy of Make in India campaign.”
The invention was made possible with financial support from MNRE, from which , Dr. Antony has a National Solar Science fellowship, and the research was done at the National Centre for Photovoltaics Research and Education at IIT Bombay’s Powai campus.