Manufacture of solar panels. Image: Humphery Shutterstock

After years and years of research, scientists have been able to identify the main reason why the theoretical efficiency of the solar panels they are built for is not achieved.

More and more homes have solar panels installed, in addition to large solar parks that generate electricity continuously. However, they still have a big problem, their efficiency, which is why several researchers / companies developing solar panels are trying to make them even more efficient.

Today, almost 40 years after its invention, we managed to find out why we can’t increase the efficiency of solar panels. This is a silicon defect, which had not yet been identified by anyone, by any study.

The defect identified in this compound is the main cause of the 2% drop in solar cell efficiency in its first few hours of use (i.e. light-induced degradation – LID).

Considering the increase in the number of solar panels in the world, this decrease in their efficiency represents a high cost in energy that they could generate.

This loss of efficiency of solar panels in the world is equivalent to the total energy produced by the 15 nuclear power plants in the United Kingdom (for example). Therefore, finding this “problem” can help develop new methods to compensate for this loss of efficiency.

Light-induced efficiency degradation (LID) has a negative impact on the environment and therefore has been of scientific interest in recent decades.

How was solar panel efficiency failure discovered?

Decades after the discovery of solar panels, more than 250 research papers on the topic of solar panel efficiency, only now, using a technique called Deep level transient spectroscopy (DLTS), the problem turned out to be silicon.

As the electrical charge in solar cells is transformed by sunlight, the flow of electrons is conserved, which in turn reduces the level of electrical energy that can be produced.

A fault that lasts until the solar panel is fully heated. Now, following the discovery by the team of which Iain Crowe, University of Manchester, we hope that this can be corrected.

Another related finding is that higher quality silicon has electrons with a longer lifespan, reinforcing the idea that the connection to silicon is associated with the degradation of the efficiency of solar panels.

When the material is heated in the dark, a process commonly used to remove silicon bonds, there appears to be a reversal of degradation.

Much remains to be done to improve the efficiency rates of solar panels, and teams of researchers around the world are working on this topic.

By solving the mystery of light-induced degradation, solar parks can benefit from the study and see their efficiency rates improved.

A 2% efficiency loss may not seem like a high percentage, but when you count all the solar panels installed in the world, it turns out to be a huge loss!

More information: www.manchester.ac.uk