Have you ever used a calculator with a solar cell? That solar cell my friends is thin film solar technology in the form of amorphous silicon. Amorphous silicon is one of the types of thin film solar modules that is employed today. Thin film panels, although not as popular as their crystalline counterpart, are still prevalent today and certainly play a role in solar going forward.
What is Thin Film?
Thin film modules, when compared to traditional crystalline solar modules, are indeed thin. Sometimes extremely thin. According to UnderstandSolar,
“thin film technologies employ different elements that allow the cells to be up to 350 times thinner than the traditional wafer. This material can then be layered over coated glass, metal, or plastic to create a solar cell, and allows for many different types of materials and objects to produce energy.”
Main Types of Thin Film
The glass, metal, or plastic that elements are placed onto is known as a substrate. Although raw materials, substrates, and elements differ, the aim of producing the photovoltaic effect remains universe. The three main types of thin film used today are amorphous silicon, cadmium telluride, and copper indium gallium diselinide.
Amorphous silicon, featured in calculators, is also featured in large commercial roof applications. Amorphous silicon modules can either stick directly on roofs or be integrated as part of the roof. Also known as aSi, amorphous silicon is one of the most popular types of thin film modules and is comprised of silicon and silane gas.
Cadmium telluride is featured on windows and is rapidly gaining exposure (literally and figuratively). A glass substrate is featured as well as a second layer of glass, and cadmium telluride is also referred to as CdTe. Although telluride is a rare earth metal, raw material costs are generally low.
Copper indium gallium diselinide modules (CIGS) may be flexible or rigid, depending on the substrate. CIGS cells and modules can be manufactured in nanonmeters, which is significantly thinner than even other thin films. This allows CIGS modules to require less raw materials, and thus lower costs.
As technology continues to improve, other types of modules may also be created. In addition to thin film and crystalline modules, one new type is hetero-junction modules. Although this technology is extremely new, hetero-junction modules take the best applications from crystalline and thin film and offer premium applications as evidenced by the solar pioneering company Meyer Berger. Check out their amazing pdf regarding hetero-junction modules here.
Topaz Solar in California is currently the largest nationwide solar plant and is comprised of thin film panels.
Advantages and Disadvantages
Renewable Energy World published an article why thin film is the future of solar and why it will eventually overtake crystalline modules. This, of course, is optimism, but thin film technology is not to be ignored. Generally speaking, the raw materials and the manufacturing process for thin film modules is cheaper than their crystalline counterparts. Efficiency in thin film is also comparable to crystalline, and the NREL study is encouraging going forward. As the name suggests, thin film modules are also thin, offering less weight resistance, and are aesthetically pleasing to many.
Some of thin film’s raw materials, albeit cheaper in cost, are rare and toxic, as environmental studies are ongoing. Durability and heat retention are also areas of concern for thin film modules.
Thin film panels will be a product utilized in solar’s future. Just how much remains to be seen, as thin film and crystalline will undoubtedly experience growth. Perhaps thin film will overtake crystalline, perhaps not–at any rate, it is a sure win-win for all solar!
Need more information on going green and ready to take the next step? We are here for you at Bay Area Solar Solutions LLC, where your solar needs come first!