Photovoltaics, the technology that makes solar panels possible, has been continuously evolving, especially in the past decade and has provided us with very promising new discoveries and advancements. One of these came just this month, where a team of researchers from Incheon National University in South Korea has developed a new design for a “transparent solar cell”.
Transparent solar cells have been quite the “holy grail” of PV researchers as it has the potential of being integrated into windows, vehicles, cellphone screens and many other everyday items. Imagine having a house or an office building whose windows are capable of producing energy and powering your appliances. You give these unused and passive surfaces another purpose and functionality. That’s great, right?
But if you think about it, a transparent solar cell seems like a paradox because solar cells absorb the energy from sunlight and convert it to electricity, while being transparent means that it allows light to pass through it without being absorbed. So, how do transparent solar cells work?
Right now, the designs of solar cells, which are the most basic building blocks of solar panels, can be categorized into two. They can either be the “wet type” or those that are based on solutions or the “dry type” or those that uses metal-oxide semiconductors for their construction. The “wet type” solar cells are used in the more traditional types of solar panels, which are monocrystalline and polycrystalline solar panels while the “dry type” solar cells are the newer type of solar cell technologies, which include thin-film solar panels.
The “dry type” solar cells have a distinct advantage of also being able to absorb UV light and convert it to electricity. The researchers at Incheon National University, however, improved upon this technology even further by allowing the solar cell to absorb only this part of sunlight. They were able to achieve this by inserting an ultra-thin layer of silicon (Si) between the two metal-oxide semiconductors of the solar cell.
The researchers of this new technology view this major breakthrough as the beginning of a new class of solar panels, which can be used in a wide variety of new areas and applications. They envision this new technology to be used in building materials, most especially for glass buildings and mobile and other electric devices like smart phones and electric cars. They are even working on using other innovative materials like 2D semiconductors, nanocrystals of metal-oxides and sulfide semiconductors.
However, before we get too excited regarding this news, we need to keep in mind several things:
We would not probably see transparent solar panels in the market in the near future. A new invention or technology like this type of transparent solar cells goes through many more stages of development to be made available in the market. Also, it will need to overcome many more challenges like the need for funding and manufacturing techniques and methods.
While transparent solar cells can be used for passive building components like windows, this would mean that most of the time, you would not have control over their tilt and orientation. You need to be content with a 90-degree tilt and whatever orientation that the windows are facing. This would mean that transparent solar cells would most probably not produce as much energy compared to traditional solar panels that are installed on the roof. But since these turn passive building components like windows to power-generating units, any amount of energy that they can produce is still a plus.
We are still not sure whether the economics of this new technology will allow it to be widely used in the market. As an example, take a look at Tesla’s solar roof tiles. They are quite similar to transparent solar panels in the sense that they directly replace building components with power-generating ones. Even with the huge promise and potential of this new technology, it still turned out to be a flop due to a lot of factors. One, its target market was limited to new house constructions. Aside from this, the installation of these solar roof tiles required specialized tools and expertise. This means that they can’t be installed by traditional workers, unlike normal roof tiles, which results to a significantly higher cost of installation. Lastly, traditional solar panels have been in the market for decades already, which means they have had decades of development in both the technology and in manufacturing as an advantage. The result is that these traditional solar panels are still superior not only in terms of quality, but more importantly, with its cost. Newer technologies like these solar roof tiles, would really have a hard time competing in the market.
Whether or not transparent solar panels will be the next big thing for solar energy in the near future, one thing is certain, the future of solar energy is very bright and it is still shaping up to be the energy of the future.