The accumulation of dust on solar panels is a significant problem - it can reduce the output of photovoltaic systems by up to 30 percent in just one month. Therefore, regular cleaning is essential for such installations.

However, cleaning solar panels currently consumes an estimated 10 billion litres of water per year. Attempts at waterless cleaning are labour-intensive and often lead to irreversible scratches on the surfaces, which also reduces efficiency.

Now, a team of researchers at MIT has developed a method for automatically cleaning solar panels or mirrors of solar thermal systems that is contactless and does not require water, and could significantly reduce the dust problem.

Dust particles are repelled

The new system uses electrostatic repulsion to dislodge dust particles and virtually bounce them off the surface of solar panels without the need for water or brushes. To activate the system, a simple electrode is placed directly over the surface of the solar panel, which imparts an electrical charge to the dust particles. A charge applied to the panel itself then repels them. The system can be operated automatically with a simple electric motor and guide rails on the side of the panel.

By eliminating the need for water delivery, dust accumulation and overall reduced operating costs, such systems have the potential to significantly improve the overall efficiency and reliability of solar installations, the researchers said.