Though the usage of typical solar panels had long been referred as the clean source of energy, the process involved in making them are not quite as clean. Most solar panels are made with refined silicon which requires a vast amount of energy to refine them. Unfortunately this energy generally comes from power plants that emits carbon to our atmosphere.
As an alternative to these silicon, scientists are focusing on thin-film of Perovskite, which are fairly low cost and much more flexible. It can be produced with much less energy with almost zero carbon (CO2) emission. Though these alternative solar cells are quite promising, it is important to remember that producing perovskite at a large scale is a bit challenging as it is inherently unstable in nature.
A Perovskite Solar Module Produced by Rapid-Spray Plasma Processing. © Nick Rolston.
Perovskite solar cells are thin films of synthetic crystaline that are made from chemicals (iodine, carbon and lead) which are cheap and are available in abundance. At a temperature of near boiling point of water, these cells can be grown in open-air laboratories. On the other hand silicon based solar cells requires refining them at 3000-degree Fahrenheit which requires lots of energy.
Scientists at Stanford University has invented a new process of manufacturing perovskite which can convert sunlight to electricity at around 25 percent of efficiency which is similar to the silicon based cells. As of now, it is almost impossible to make perovskite in bigger cells as such process produces defects that significantly decreases cell efficiency.
“Most work done on perovskites involves really tiny areas of active, usable solar cell. They are typically a fraction of the size of your pinky fingernail,” said Rolston, who co-lead the study with William Scheideler.
A rigid silicon cell can last around 20 to 30 years but perovskite generally degrades way faster depending on the exposure to heat and moisture. To mitigate the large-scale production issue, scientist had introduced a new patented technology called rapid-spray plasma processing which you can check out from the demonstration video below.
Stanford Scientists Demonstrates Perovskite Solar Cell Manufacturing Process. © Stanford.
The Stanford team estimated that their perovskite modules can be manufactured for about 25 cents per square foot which is also far less than the $2.50 or so per square foot needed to produce a typical silicon module. Traditional silicon modules can produce electricity at a cost of about 5 cents per kilowatt-hour. However, it may be possible to generate same amount of energy at a cost of 2 cents per kilowatt-hour only if the scientists can use single perovskite based module for 30 years. So, we are basically back to the same issue, durability.
The question for durable, stable and efficient perovskite based solar modules are still out there that need to be answered before we can make these modules as a commercially viable alternative to traditional solar module. However, there is no way of denying the fact that the newly invented manufacturing process is one step towards even more greener solar energy.