The difference between CIGS and Crystalline solar
Here I will explain the difference between today’s (summer 2017) widely used crystalline solar cells and CIGS, which have now become economically a better investment in most cases.
Let me start with in general terms explain how the “old” crystalline technology works.
It’s roughly a slice of pure silicon that is cut into very thin slices (called a wafer) and the wafer is then laid on a conductive backing glass or plastic and a conductive glass top on top.
When the sun shines through the top glass plate and reach the silicon, electricity is generated and that is the one we harvest.
That’s the quick explanation, but it’s comprehensive anyway.
CIGS is a thin film technology, but it is important that it is not confused with another thin film solar, that is mostly silicon-based. CIGS does not use the previously rare element of silicon. CIGS stands for: Copper Indium Gallium deSelenide and these are the 4 elements in certain mixing ratios that are the active substance in CIGS.
The construction of CIGS is very different from crystalline as you burn the 4 elements onto a conductive surface with a laser. This can be on a glass plate coated with a metal foil and as a glass sheet that is also coated with a metal film (transparent) on top, it produces electricity.
But since the active substance is in powder form, it offers more options! Therefore, you can also burn the 4 elements on eg. A piece of “tin foil” and on top put a flexible transparent laminate and now you have a very flexible solar module.
The differences between CIGS and crystalline solar cells
Here you can see some of the differences on CIGS and crystalline solar cells
|CIGS Solar||Crystaline Solar|
|10% Shadows effect||reduce the production with max 10%||reduce the production with up to 80%|
|CO2||uses significantly less power to produce than crystaline||Uses a lot of power during the production phase|
|Elements usage||Uses: Copper Indium Gallium and Selenide.||Based on Silicium.|
|Flexibility||Very flexibel modules availible||only semi flexible, due to the wafer build|
|Micro cracks||You will have to penetrate the module to make cracks... which then might not be micro....||Due to the wafer build, the crystalline module are vulnerable to microcracks which will decrease efficiency and might in extreme cases course fire.|
|Durability||Due to the "powder" build up, there is no wafers to crack or damage||Wafers don't like transportation or pressure (from Snow and wind)|
|Lifetime||Same expected liftime|
|Temperature impact||Power production decline approx. 0,3% per degree Celsius the temperature raises||Power production decline approx. 0,6% per degree Celcius the temperature raises|
|Effeciency (summer 2017)||up to 17%||Up to 23%|
|Weight||down to 2,9 kg/m2||down to 5,5 kg/m2|
|Typically warranty||5 or 10 years workmanship. 25 years powerloss||3 or 10 years workmanship. 25 years powerloss|
|Looks||Typically all black, but can be produced in all colors and even transparent||Black for Mono crystalline and blueish for poly crystalline|
As you can see, there are many differences and often CIGS is the best technology for many projects.
There is no big difference in price on CIGS and Crystalline solar cells, and within the flexible solar cells, CIGS is clearly preferable.
It is expected that prices for both types of solar technologies will fall further in the coming years, but at Energig, we expect CIGS to fall the most, as there are steadily a number of major production benefits that can be obtained.