The Cost of Cleaning Solar Panels and a Possible Solution

– Teresa Madaleno:

The global solar power market is expected to grow from just over 184 billion to 293 billion by 2028. While this sounds like great progress for the environment, what many people don’t consider is the amount of water required to clean the panels.

Generally, small solar power systems require a modest amount of water for cleaning collection and reflection surfaces, but with solar expected to reach 10 percent of global power generation by 2030, it becomes a significant amount of water. Regular cleaning is a must if systems are going to operate efficiently. The good news is that a group of engineers believe they have a waterless solution to the dust that accumulates on solar panels. They think it can be especially useful in areas of the world where water is limited.

Engineers at Massachusetts Institute of Technology (MIT) have devised a system that uses electrostatic repulsion to cause dust particles to fly off panel surfaces so there is no need for water or brushing. Here’s how it works – an electrode passes just above the solar panel’s surface, putting out an electrical charge that repels the dust particles by a charge applied to the panel itself. It can function automatically with an electric motor and guide rails along the side of the panel.

The same team of engineers conducted tests that demonstrated that the drop-off of energy output from panels with dust can reach 30 percent after just one month without cleaning. They calculated that globally, a 3 to 4 percent reduction in power output from panels would lead to a loss of anywhere between $3.3 billion and $5.5 billion.

Some of the largest solar panel systems in the world are in desert like regions. In many cases, water must be trucked in from a significant distance away. Some people try dry brushing or scrubbing, but it can leave deposits on surfaces thus reducing light transmission. The automatic cleaning system could reduce the time, energy, and costs of cleaning with water.

You can read more about the solar panel cleaning solution in a paper published in Science Advances.