The Future of Solar? Transparent PV Cells
Most of us are probably at least somewhat familiar with the existence of solar PV (photovoltaic) cells, being the driving forces behind the energy created in modern day solar panels, but a less commonly known relative to the solar PV cell is a new idea in the works known as transparent PV cells, or TPV’s for short.
In essence, TPV’s are see-through solar panels that combine visible transparency and solar energy conversion, which are being designed with the hopes that such a breakthrough can revolutionize access, especially in urban areas (such as apartment buildings), to solar energy.
1. How They Work
When it comes to PV cells, their ability to generate electricity stems from being able to convert light into electricity. While it may seem crazy that a piece of glass can complete this task, it is actually not much different from regular PV cells in terms of how energy is generated.
These small slabs of glass are in fact not actually converting light into electricity, but rather, they are designed to capture and direct light to the outer edges of the slab via the use of embedded quantum dots, which are essentially particles of silicon (or semiconductors in general) that capture smaller wavelengths (less than 640 nanometers) of light and reemit them as longer wavelengths that reflect within the window pane rather than escaping due to the properties of total internal reflection. A thin layer of solar PV cells situated around the edges then convert this trapped light into electricity as they normally would.
This process has been successfully demonstrated by a team of researchers at the Michigan State University, where they have increasingly enhanced the efficiency of their TPV prototype by giving the see-through area a slightly darker green tint.
While the current TPV prototypes still are not optimal, their properties offer many promising breakthroughs for the future, as they continue to develop and become more effective.
2. Are TPV’s Set to Replace Normal PV Cells?
When it comes to the efficiency of solar PV cells, years of innovation and research have led to the current average commercial energy efficiency for solar PV cells to be between 15 and 20 percent. However, solar panels have been developed that have reached a net efficiency as high as 40%.
For comparison, the United States Energy Information Administration found that present day fossil fuel energy ventures provide an energy consumption efficiency at around 30 to 40 percent (varies depending on net energy consumption), with fossil fuel ventures already reaching their peak in terms of innovation and usability.
Unlike regular solar PV cells and fossil fuels, the current highest efficiency for transparent PV cells is about 7 to 8 percent. It is worth noting that while its efficiency is much lower, it has much more room for improvement than fossil fuel energy, which is becoming more and more of a dying industry as breakthroughs like transparent solar PV cells are being made in the fields of science and engineering. Besides that, because of the abundant use of glass in architecture and development worldwide, the lower efficiency would be of little concern assuming TPV’s effectively replace regular windows as a means for expanding access to solar energy across the planet.
3. What TPV’s Could Accomplish in the Near Future
It is no question that the optimization of TPV’s can secure a society that is one step closer to being entirely renewable; however, exactly how much of an impact would this actually have?
According to the United States Census, more than 80% of the U.S. population is situated in urban areas where skyscrapers and high-rises dominate the landscape. As more cities continue to build upwards to accommodate for the continuous rise in urban growth, the amount of vertical surface area collecting sunlight increases more and more. In comparison, the amount of rooftop area on these buildings remains almost nonexistent, and usually impractical for the immense amount of power that is used by a building.
With most modern buildings being coated with glass as a means of both style and efficiency, the implementation of Transparent PV Cells in buildings would drastically increase power generation without providing any major design interferences.
Beyond buildings, transparent solar PV cells can be installed in place of car windows, on trains and buses, and perhaps anywhere that regular PV cells are already used, but with less obstruction to design and style. It is quite astonishing to think about how much glass is used in various different designs, and were it to be replaced with TPV’s, the amount of energy generated may be enough to render society to a status driven entirely by renewable energy.
References:
[1] https://solarmagazine.com/solar-panels/transparent-solar-panels/
[2] https://www.census.gov/programs-surveys/geography/guidance/geo-areas/urban-rural/ua-facts.html
[3] https://news.energysage.com/what-are-the-most-efficient-solar-panels-on-the-market/
[4] https://www.eia.gov/tools/faqs/faq.php?id=107&t=3
