Can dust stop solar panels from working?

If dust is not cleaned from panels installed in those areas, it can have a detrimental impact on solar production. Research has observed that “the reduction in solar efficiency due to dust in photovoltaic panels is approximately 40%” in dust-prone areas. Dust on solar panels significantly reduces their production, so they must be kept clean. But what's the best way to do that? Scientists at the Massachusetts Institute of Technology (MIT) say they have a solution.

The gradual buildup of dust on solar panels can reduce their efficiency by nearly 30 percent after a month of operation. In some context, solar energy losses of just three or four percent on a global scale could mean an economic loss of at least 3.3 to 5.5 billion dollars. As climate change intensifies dust storms, solar panels can quickly lose their efficiency if they are not cleaned several times a month. Not only did we want to help you clean your solar panels, but we also wanted to help you decide when it's really necessary to clean them.

An opposite charge applied to a transparent conductive layer only a few nanometers thick deposited on the glass cover of the solar panel repels particles and, by calculating the correct voltage to be applied, the researchers were able to find a voltage range sufficient to overcome the attraction of gravity and adhesion forces, and cause the dust to rise. The new technique works by passing a simple electrode, a conductor of electricity, which could be a simple metal rod, just above the surface of the solar panel. A small electric motor, perhaps using a small part of the panel's own output, would drive a system of belts to move the electrode from one end of the panel to the other, causing all the dust to fall. So far, a UK-based company, Solar Sharc, has already released a dust-repellent coating for solar panels.

Although the global capacity of solar parks currently exceeds 500 gigawatts, researchers estimate that up to 10 billion gallons of drinking water are used each year just to clean solar panels. As MIT engineers prepare to make their new system scalable in the future, other researchers are working to develop a solar panel coating technology that reduces dust accumulation. Now, a team of MIT researchers has devised a way to automatically clean solar panels, or the mirrors of solar thermal plants, in a system without water and without contact that could significantly reduce the dust problem, they say. This led both to opt for a different method of using electrostatics to clean terrestrial solar panels.

This could prevent dust from accumulating on the surface of solar panels and reduce the amount of water needed to clean them. However, it is currently estimated that around 10 billion gallons of water are used to clean solar panels per year, enough to supply drinking water to up to 2 million people. Emmett Smith, a reporter for Mashable, highlights how MIT researchers have developed a new technique to remove dust from solar panels without using water. Laboratory tests carried out by Panat and Varanasi showed that the decline in the energy production of the panels occurs abruptly at the beginning of the dust accumulation process and can easily reach a 30 percent reduction after only one month without cleaning them.

So, if you want the panels to last a long time and work at maximum efficiency, then you might want to consider cleaning them well...