The biggest hurdles in the spread and acceptance of solar lighting have been the high coast of solar panels and their low efficiency in converting sunlight into electricity. In the last few years, prices of solar cells have come down dramatically. This has forced people to take more interest in this alternative source of energy that is not only green but also clean. But if there was a damper, it remained low efficiency of solar cells in absorption of sun’s energy. Professor Challa Kumar has developed a gel that improves the ability of solar cells to absorb sun’s energy. This new invention promises to lower the prices of solar cells while increasing their efficiency by at least two times.
Unique gel that absorbs more energy from sun
Professor Challa Kumar and his team of researchers at UConn have come up with a unique gel that enables solar cells to absorb double the amount of sunlight that they are doing at present. Sun sends more light and energy on earth than mankind is able to use. The rate at which reserves of fossil fuels is depleting around the world has started to ring alarm bells among governments, especially countries that depend heavily upon import of oil from foreign countries.
According to Kumar, the lead researcher in this study, much of the energy of the sun goes to waste as there is no way to trap this energy that is sent in a wide window of wavelengths. Kumar presented his views recently in Boston where 250th National Meeting and Exposition of American Chemical Society were held. Kumar said that to be able to produce large quantities of electricity using sunlight, it is essential to be able to absorb a high percentage of sunlight that falls on earth. For this, it is necessary to harvest the wide spectrum of wavelengths in which sun sends energy to earth.
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Reason why solar cells have low efficiency
At present, the most common way to tap sun’s energy is to place photovoltaic solar cells made of silicon in panels over rooftops. These cells convert photons present in sunlight into electricity. However, sunlight touches earth in a wide spectrum. Solar cells are unable to absorb photons present in the blue part of this spectrum. Photovoltaic cells therefore miss out on a large quantity of photons present in sun light.
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Gel that increases efficiency of solar cells
Kumar built an antenna with the help of his team. This antenna is able to collect photons present in the blue spectrum of sunlight through a process called artificial photosynthesis. This process actually changes blue photons into lower energy particles of light that can be tapped and converted into electricity. Just as plants make chlorophyll in the presence of sunlight, Kumar and his team made use of a variety of biodegradable materials to trap sunlight. They used many concoctions that included ingredients like cow blood protein, organic dyes, and even fatty acid found inside coconuts.
When these ingredients were mixed in a particular ratio, they formed a gel that seemed to work wonders for the photovoltaic cells. These cells started to absorb double the amount of sunlight than before. This was because they were able to absorb unused photons in sunlight. These cells thus produced double the amount of electricity also. Kumar said that many teams across the world are trying to come up with such a gel but his team is the first to achieve it. He also said that it was very easy and cheap to make this gel. However, what is important is to make sure that the gel remains stable and strong for many years to be able to be used in solar cells.
