The Environment Magazine

Alex Tong
The Dorris Eaton School, San Ramon, CA 94583

Since the Industrial Revolution, we have been using fossil fuels such as coal, oil, and natural gas as our main source of energy. Fossil fuels, when burned, release carbon dioxide and pollute our environment. Unfortunately, in modern society, almost everything is powered by fossil fuels. Currently, around 80 percent of our energy is produced by burning fossil fuels. Each year, we burn around 490 exajoules of fossil fuels, equivalent to almost 80 billion barrels of oil. 

Fossil fuels are harmful to the environment, pollute our air and atmosphere, and are limited in supply. In fact, it is estimated that all fossil fuel reserves will be used up in only 100 years, forcing us to find other alternatives. In recent years, solar power has become the fastest-growing source of green energy. Solar power is generated by solar cells or panels from sunlight. There are many types of solar cells, often classified by generation. 

The first generation of solar panels are the standard panels you see on rooftops. They are made from crystalline silicon (c-Si). Crystalline silicon solar panels are durable and highly efficient. They last for more than twenty-five years, and they average around 15 to 20 percent PCE (power conversion efficiency). This means that 15 to 20 percent of solar light that is absorbed by the panel will be turned into usable energy. However, they are rigid, heavy, and very expensive. A six-kilowatt solar system costs more than $15,000, averaging out to around $2.50 per watt. 

The second-generation solar panels are based on thin-film technology. They are most commonly cadmium telluride (CdTe), copper indium gallium selenide (CIGS), and amorphous silicon (a-Si, TF-Si) based. These types of solar panels are comparable to crystalline silicon panels. They are flexible and lightweight, but are made from rare earth metals and thus have a limited supply. 

In 2009, researchers at Tokyo University first discovered that utilizing perovskite structures in solar cells could be beneficial. Perovskite-structured solar panels, while still not commercially available, have shown to be a better alternative compared to traditional solar panels. 

Perovskite has been proven to be more renewable than traditional solar panels. Perovskite is an extremely common crystal structure that makes up around 38 percent of the Earth’s mass, with most being found in the mantle. Silicon solar panels, however, use rare earth metals such as neodymium and praseodymium. Another benefit of perovskite solar panels is that they are flexible and light. They are also easy to install and can be placed almost anywhere, including curved or sharp surfaces. Meanwhile, silicon solar panels can only be placed on flat surfaces and are difficult to install. Although, the most important benefit of perovskite solar panels is their energy efficiency. Today, experimental perovskite cells can reach up to 25 percent PCE.

While perovskite solar cells have many benefits, they also have their share of disadvantages. Perovskite solar panels have good efficiency in moderate temperatures, but lose energy efficiency in warmer climates. Another drawback of perovskites is that they are not as durable as silicon panels. When exposed to weather and erosion, they degrade quickly and will not last. Most perovskite-structured solar panels contain tin or lead, which can be toxic and dangerous when exposed to people. These are all things researchers and scientists will have to improve on to push widespread commercialization of perovskite solar panels. 

Figure 1: Flexible perovskite solar modules (Source: https://en.dazhengtop.com/)

Perovskites have improved tremendously since its debut. Now, a Chinese company, DaZheng, is working to bring it into the market. In a few years, solar films will be everywhere: on walls, windows, and even our backpacks and jackets. It is safe to say that perovskites hold a promising future in our quest for renewable energy and a better environment.

References

Sun, J., Wu, J., Tong, X., Lin, F., Wang, Y., & Wang, Z. “Organic/Inorganic Metal Halide Perovskite Optoelectronic Devices beyond Solar Cells.” Wiley Online Library, March 2018,
https://onlinelibrary.wiley.com/doi/10.1002/advs.201700780

DaZheng (Jiangsu) Micro Nano Technology Co., Ltd. “Technology of Power.” https://en.dazhengtop.com