Why is silicon used in solar panels?

Fast read

The use of silicon-based solar cells is prevalent in modern solar panels due to several reasons. Silicon is a semiconductor that efficiently generates electricity from light, with high-quality cells achieving efficiencies of around 25%.

Its abundance in the earth's crust ensures a plentiful supply for mass production of solar panels and other applications. Silicon panels easily integrate into existing electrical grids, generating DC electricity that can be converted to AC through inverter solutions.

Silicon is non-toxic and has a minimal environmental impact, emitting no greenhouse gases during use and being recyclable at the end of life.

With well-established production methods, silicon solar panels are cost-effective and durable, withstanding various environmental factors. While research continues on other materials like Perovskite for potentially higher efficiency, silicon remains the ideal substance for solar panels due to its many advantages. including a relatively low cost.

Is there silicon in solar panels?

In the past, there were solar panels made using a number of materials including cadmium, amorphous silicon copper indium and gallium compounds. Nearly all solar panels that are now used around the world including Australia use silicon-based solar cells.

By delving into the characteristics and applications of silicone, students and professionals alike can gain insights into the ongoing evolution of solar energy. The use of silicone in solar panels represents a perfect fusion of chemistry and engineering, highlighting the interdisciplinary nature of modern technological advancements.

Efficiency

Silicon is a semiconductor so it is photosensitive (Sensitive to light) and able to generate electricity from light very efficiently. The conversion efficiency of silicon solar panels has significantly increased over time. Currently, high-quality cells can attain efficiencies of over 25% and panels over 22 to 23% efficiency.

This translates to the ability to produce useful power from more than one-fifth of the sunlight they receive. For a variety of applications,  including solar panels this level of efficiency is regarded as respectable and economically viable. So in short if the sunlight that hits the panel is 100% of the energy, then 23% of this energy comes back in the form of electricity. The rest is lost in the conversion.

Abundance 

Silicone’s primary ingredient, silicon, is found in abundance in the Earth’s crust. Comprising nearly 28% of the Earth’s crust by weight, silicon is second only to oxygen in terms of abundance. Silicon is most commonly found in the form of silicon dioxide, or silica. Therefore silicon is present in sand, quartz, and various types of rocks like granite.

Due to its availability and abundance, silicon will always be in plentiful supply. This is an important aspect of the mass production of solar panels. It also means the initial raw material is relatively cheap. This helps to keep the cost of PV systems down.

Mining silicon

The extraction of silicon begins with the mining of silica-rich sands and rocks. Quartz, a crystalline form of silica, is often targeted due to its purity. The mining process involves standard methods like blasting and drilling. After this, the ore is transported for further processing.

Then the silica is refined and reduced with carbon in high-temperature furnaces, eventually forming metallurgical-grade silicon. Further purification processes in high-tech dust-free facilities are undertaken. These yield electronic-grade silicon, used in semiconductors and photovoltaic cells. The chemically modified silicone is used in solar panel encapsulants and general sealants.

The extraction and processing of silicon must be managed responsibly and consider the environmental impact and energy consumption. These factors affect the overall sustainability of the silicon and silicone products used in solar technology.

mining
Close to 30% of the earth’s crust is made up of silicon, making it one of the most abundant raw materials

Compatibility 

Silicon solar panels can easily be incorporated into the infrastructure and electrical grids that are already in place. They generate direct current (DC) electricity, which is easily transformed into alternating current (AC) by means of an inverter solution. Due to its compatibility, solar energy can be adopted and integrated into the current electrical system without requiring major changes.

Environmental effect 

Silicon is a non-toxic material, as opposed to other materials that have been used in the past to make solar panels such as the rather toxic Cadmium. Furthermore, compared to other energy sources, silicon solar panels have a relatively minimal environmental impact. Used in solar panels via solar cells they produce electricity without emitting greenhouse gases or polluting the air while in use. More sustainable end-of-life management is also made possible by the fact that silicon is a relatively easy recyclable material and that the recycling infrastructure for solar panels made of silicon is always increasing.

Cost-effective

Over many decades, solar cell technology has undergone tremendous development and improvement. The production methods for silicon-based photovoltaic cells are efficient. The affordability and scalability of solar panels, which make them a popular option for both residential and utility-scale installations, are made possible by the manufacturing technology’s maturity.

solar cell manufacturing using silicon

Durability

Extreme temperatures, dampness, and UV rays are just a few of the environmental factors that solar panels must contend with. Solar panels’ lifetime is guaranteed by silicon’s outstanding stability and toughness. As a result, there is less chance of performance degradation or failure because it can survive heat cycling and maintain structural integrity for extended periods of time. This is why solar panels can have warranties for 25 years

Other than solar wafers and then cells silicone is used in other solar panel-related applications such as:

Encapsulation material

Silicone’s unique physical and chemical properties make it an ideal encapsulant material for solar cells. It protects the cells from environmental factors like moisture, dust, and mechanical stress, ensuring longevity and performance stability.

Adhesive bonding

Solar panels often require bonding between different layers and materials. Silicone adhesives provide an excellent solution, offering strong bonding while accommodating thermal expansion differences between the materials.

Gaskets and seals 

Gaskets and seals made of silicone rubber are used in solar panel assembly to ensure proper sealing of joints, enhancing the panel’s resistance to harsh weather conditions.

Have you heard of flexible solar panels?

With the advancement of flexible solar panels, silicone plays a vital role in manufacturing lightweight modules. These flexible panels are gaining popularity for portable applications and building-integrated photovoltaics.

In summary, silicon’s wide availability, semiconductor qualities, stability, manufacturing maturity, efficiency, compatibility with existing infrastructure, adaptability, and environmental sustainability all contribute to its employment in solar panels. There is continued research into other materials that could be used to manufacture solar panels which have the potential to be more efficient than silicon cells. This includes Perovskite which has shown cell efficiencies of close to 30% as opposed to silicon cells which currently in applications peak at around 25%.

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