Research Recap: Transparent Solar Panels
August 9, 2021 | Claris Lam
Many people are aware of solar panels, used to generate electricity for buildings and offices. However, did you know that transparent solar panels exist? These transparent panels can be used for areas such as windows, buildings, and many other surfaces. This technology could, in fact, give buildings the potential to produce their own solar energy. Could more buildings be built with transparent panels and become new energy sources, in the near future?
What Are Transparent Solar Panels?
Transparent solar panels are thin, plastic-like transparent panels that can be affixed to clear surfaces, such as car windows and buildings. These panels can also be used on other areas such as skyscrapers with large windows to mobile devices such as phones, laptops and e-readers. These solar power windows can simply replace the traditional glass windows in offices and homes, and hold the potential to turn every building in the world into a solar producer.
The solar cells in transparent solar panels must absorb sunlight (photons) and convert them into power (electrons). The cells selectively harness part of the solar spectrum that is invisible to the naked eye, while allowing normal visible light to pass through. Using transparent solar panels would allow for a mass reduction of the use of fossil fuel resulting in clean, effective, and affordable energy that may also help save the environment. This new technology could aid in the elimination of global energy consumption away from fossil fuels.
Solar Cladding with all black solar modules on Red Deer College, installed by Kuby Energy in 2019. Image by Cooper & O’Hara / Manasc Isaac. From https://kubyenergy.ca/blog/bipv-and-architectural-solar-panel-applications
Though transparent solar panels have their advantages, there are also a few concerns with using this technology. First, these technologies are not easily available. It is only until recently that most solar panel installations relied on products imported from outside the country and were customized instead of mass-produced. Canadian companies such as Mitrex and PV Technical Services started offering access to their own solar cladding and shingles that can be locally developed and manufactured, to remedy this issue, but it is a slow process. Mitrex expected to open a new Toronto factory in July 2021 to scale up manufacturing cladding for its first customers, which is expected to be installed by the fall. Other companies, like Kuby Energy, currently plan to sell Tesla’s Solar Roof when it’s available in Canada, which is expected to later this year.
Another issue with this new technology is dealing with the technical and regulatory challenges to keep it working efficiently. These products are regulated both as building materials and electrical materials, so they have to meet two sets of requirements. Much testing and working with the government to write regulations for a new product is required to make sure they are qualified for appropriate use. To encourage adopting these technologies, building codes need to be modified and governments need to provide the right incentives. Additionally, most tradespeople are not familiar with transparent solar panels and need to be further educated to work with the material.
A third problem is the cost of these technologies. Upfront, transparent solar panels and related products are expensive for purchase, although the electricity generated over its lifetime should offset that eventually.
What Impact Could Transparent Solar Panels Have Globally?
Transparent solar panels are already being researched and implemented all around the world. For example, Heliatek GmbH, a German company, developed partially transparent solar panels, which absorb 60% of the sunlight they receive! The efficiency of these panels is 7.2%, compared to an efficiency of 12% for conventional solar panels of this manufacturer. The reason for this reduced efficiency is because 60% of the light is absorbed by the panel while the remaining 40% is transmitted through the panel. Partially transparent solar panels have high commercial potential for office buildings with large south-facing glass areas already using tinted glass to reduce the transmitted sunlight.
Meanwhile at Michigan State University, a team of scientists have produced a fully transparent solar panel that resembles normal glass! The team used organic salts that absorb specific invisible wavelengths of light, such as ultraviolet light, to make the panel’s material. The invisible light wavelengths are then transformed and move to the edges of the panels, where stripes of photovoltaic solar cells convert it into electricity. The efficiency of the fully transparent solar panels is currently about 1% with an estimated potential of 5%. Compared to the average efficiency of 15% for conventional solar panels, efficiencies of 5% and 7.2% for the fully and partially transparent panels respectively are still quite low. In practice, despite these low efficiencies, these results only mean that the less efficient panel needs to be larger than the more efficient one in order to produce the same amount of electricity. This clear solar panel could turn virtually any glass sheet or window into a PV cell!
What Impact Could Transparent Solar Panels Have In Canada And KW?
Canada is also investing opportunities into creating transparent solar panels as well. Ever since Elon Musk, CEO of Tesla, started selling solar panels back in 2017, numerous made-in-Canada options emerged as options for use in Canada in the form of building-integrated photovoltaics (BIPV). BIPV systems are like other solar panels because they generate clean energy that can be used for backup power or sold to the grid. However, they need to be designed differently in order to serve other functions, such as keeping out the wind and rain or letting natural light shine in. Additionally, unlike traditional solar panels that are attached to buildings, BIPVs are built into the buildings’ exteriors as key elements, including windows, shingles, skylights, and balcony railings. Due to these different design requirements, BIPV panels come in wide varieties of shapes, sizes, colours and transparencies.
A Toronto-based company, Mitrex, makes BIPV cladding and plans to make highway sound barriers. Those are two things that are often made of concrete, which has a higher carbon footprint than glass and silicon BIPV panels. Hadizedah, Chief Executive Officer of Mitrex, says the goal over the next few years is to lower the cost of Mitrex’s products to the point that they can be offered at no up-front cost to customers. Instead, they would pay for the electricity generated over the panels’ lifetime.
Meanwhile, PV Technical Services, based in St. George-Brant County, Ontario, has been installing traditional solar panels for more than a decade and developed its own solar shingle in 2016. The company can put in solar shingles that both protect the roof from the elements and generate power for a cost that estimates is similar to a metal roof installation.
Another company, Kuby Renewable Energy, installed BIPVs in the Edmonton Convention Centre with a capacity of 169 kW. The company also worked on a five-storey residence at Red Deer College that’s covered with solar glass cladding on three sides, totalling 545 solar panels in all.
Overall, it’s obvious clear that transparent solar panels have their pros and cons. As more companies across Canada and around the world invest in transparent solar panels, it’s also clear that they will be more prevalent in the future. What do you think—are transparent solar panels the future of energy? Let us know on social by tagging us with @SustainableWat!
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