Why CIGS might be the key to overcoming the Solar material shortage?
Copper Indium Gallium Selenide (CIGS) is a semiconductor material that has gained prominence in the field of photovoltaics, especially in the development of thin-film solar cells. Here are the key reasons why CIGS is used in solar cells:
High Efficiency
CIGS solar cells are known for their high efficiency in converting sunlight into electricity. They offer some of the highest conversion efficiencies among thin-film technologies, typically around 15-22%, and research continues to push these limits further. This makes CIGS a very attractive option for areas where maximizing power output per unit area is crucial.
Flexible Applications
Unlike traditional crystalline silicon that requires a rigid and heavy glass substrate, CIGS can be deposited on flexible substrates. This adaptability allows for a variety of applications, including flexible solar panels that can be installed on curved surfaces, portable devices, and even integration into clothing or rollable solar panels.
Good Performance Under Low Light
CIGS solar cells perform exceptionally well in low-light conditions and under partial shading compared to other photovoltaic materials. This characteristic makes them particularly useful in geographical regions with less direct sunlight or in urban environments where buildings or other infrastructure may cast shadows over solar panels during parts of the day.
Temperature Coefficient
CIGS cells have a lower temperature coefficient than silicon solar cells. This means that their performance deteriorates less under high temperatures. Given that solar panels are typically exposed to the sun and can get very hot, the ability to maintain efficiency at higher temperatures is a significant advantage.
Less Prone to Potential Induced Degradation (PID)
CIGS cells are less prone to potential induced degradation, which is a phenomenon that can reduce the performance of solar cells due to stray currents triggered by voltage differences. This characteristic leads to better long-term stability and reliability.
Aesthetic Appearance
CIGS solar cells can be produced in a variety of colors and appearances, which makes them suitable for building-integrated photovoltaics (BIPV) where aesthetics are important. This flexibility can allow solar installations to blend in more naturally with their surroundings, making them more palatable in residential and visible urban settings.
Resource Availability
While the raw materials for CIGS, specifically indium and gallium, are rarer than silicon, the thin-film nature of CIGS means that these materials are used in much smaller quantities. Additionally, ongoing research focuses on making the use of these materials more efficient and exploring recycling opportunities.
Despite these advantages, the cost and the relative scarcity of some raw materials used in CIGS (like indium and gallium) can be seen as drawbacks. However, ongoing research and development are addressing these challenges, improving the cost-effectiveness and sustainability of CIGS solar technology.