The Spanish invention that revolutionized solar panels: it instantly increased their productivity

To optimize solar panel performance It is necessary not only to choose the location carefully. Factors as seemingly simple as yours cleaning. A dirty solar panel will not absorb photons from sunlight as efficiently as a shiny one. So the future is clearly self-cleaning solar panels.

These are plates that, as the name suggests, can clean themselves. Many research groups are working or have worked on this, and the results are getting better. Among the developed methods, one of the most interesting is nanostructured flexible coating based on graphenedeveloped by scientists from University of Almeria through research within the EMERGIA program. This is a project of excellence of the Junta of Andalusia, which aims to attract talents and innovative ideas developed in the said autonomous community.

As explained Hypertext The coating project’s principal investigator, Andres Nystal, said: “The goal of this project is to improve the efficiency of solar energy systems by developing multifunctional coating based on a hybrid photocatalytic system titanium oxide (TiO2)/graphene” The result is that the plates absorb photons to produce energy in a very efficient way, but that’s not all. “The goal is also for the surface to be self-cleaning, for which TiO2 nanoparticles have already proven effective.” To summarize, this coating combines the materials that have given the best results in previous studies with appropriate shapes to maximize its benefits and achieve Self-cleaning and highly efficient solar panels.

Keep your solar panels clean

It is suggested that solar panels should be cleaned to ensure good performance. 3 to 4 times a year. If more than 4-6 months pass and they are not cleaned, 5% to 6% of the performance of the plates is lost. But these figures are for moderate pollution, such as dust. In the presence of denser dirt, such as bird droppings, losses can reach 40%.

Cleaning them manually can be challenging, especially in facilities where there are many devices. Therefore the best solution is to use self-cleaning solar panels.

They take advantage of a phenomenon known as photocatalysiswhich involves converting solar energy into chemical energy using a material that speeds up the reaction. At the same time, some substances that make up the dirt are not only broken down, but also help eliminate it. It also releases reactive oxygen species, oxidizing molecules that attack microorganisms that may be present in this dirt. Plates that are already specialized in capturing sunlight remain clean and disinfected.

Many materials have been tested as catalysts for photochemical reactions, but the most useful so far seems to be titanium dioxide. And this not only promotes photocatalytic reactions with very good performance. It is also photostable, non-toxic, environmentally friendly and cheap.

The role of graphene in self-cleaning solar panels

Typically, titanium dioxide filters absorb mainly ultraviolet radiation through photocatalysis, but this makes the process less efficient because, according to calculations by scientists from the University of Almeria, it is not the most abundant radiation coming to us from the Sun. , For increase photocatalytic activity titanium dioxide is recommended for the nanoparticles to be absorbed into visible spectrumwhich represents 47% of the solar spectrum, instead of UV, which represents only 9% of the solar spectrum.

This is achieved through the use of hybrid photocatalytic systems with graphene-based carbon nanostructures. Essentially, by doping titanium dioxide with graphene, it changes the way it processes the solar radiation it receives, so that it primarily uses visible light.

Additionally, graphene is a very useful material in this type of process for several reasons. On the one hand, it consists of carbon atoms arranged hexagonally, which gives greater strength to CC bonds. Therefore it is very stable. Moreover, this transparenttherefore, if it is used in the coating of solar panels, it does not absorb light, and this process removes some of the radiation that reaches them.

Finally, another very useful feature of graphene is that Its electrical conductivity depends on its orientation.so the coverage can be customized as needed.

It must also be effective

It’s not just self-cleaning solar panels that are needed. Ideally, they should make the most of the energy that comes to them. For this, the ideal option is to use materials with increased conversion. These are materials that have the ability emit light in the visible or ultraviolet range spectrum after absorb lower energy radiationlike infrared. That is, they emit more energy than they absorb, making them an ideal gateway to the plates. Nanoparticles capable of carrying out this process are known as UCNP and these were the ones that were used for this coating.

What will be the final coating of these self-cleaning solar panels?

Taking all this into account, scientists from the University of Almeria have developed a silicone matrix coating that combines all these desirable characteristics. We’ve already seen that UCNP and graphene are essential, which is why they were added to conventional titanium dioxide filters that were already being used to create self-cleaning solar panels.

UCNP They must be sealed with insulating and transparent material. (from what we have already seen). For this they use silicathe composition of which is also compatible with the silicone of the main matrix.

Regarding the hybrid system titanium dioxide and graphenebuilt by orienting graphene in such a way as to eliminate the electrostatic charge that attracts dust to the plates. In this way, not only self-cleaning solar panels are obtained. In addition, they are more difficult to get dirty.

End result Easily scales to industrial levelwhich is also very important if it is to be widely used. These are all benefits of having efficient and clean solar panels. If we want to make the most of renewable energy, all the details need to be taken into account.