A Jordanian research team has designed a solar module cleaning technology that uses static electricity to remove dust from the panel surfaces. The system has an electrostatic ionizer that reduces the attraction between dust particles and their accumulation on the modules, which improves their energy output.
Electrostatic cleaning involves spraying electrostatically charged mist with low-frequency high voltage onto surfaces and objects. It is commonly used for cleaning and disinfection purposes and may involve the use of various electrically charged disinfectants, disinfectants and cleaning agents.
The researchers said that the glass in solar modules contains equal amounts of positive and negative charges, meaning it is electrically balanced. However, friction can disturb this balance, causing the material to become electrically charged.
“The electric charge creates an attraction between the dust particles and the glass due to the static charge that causes the dust to accumulate on top of the PV modules,” the researchers explained.
Academics suggested the use of an electrostatic ionizer, which use ions to neutralize static electricity, To reduce the attraction between dust particles. They used an ionizer made by UK specialist Exair, which was able to flood the surface of a PV module with a steady stream of air along its length, full of static eliminator ions. The ionizer was placed on a shaft 0.2 m from the shaft, which was attached above the panel to a screw driven by an AC gear motor.
“The charged surface attracts the appropriate amount of positive and negative ions to become neutral,” the researchers explained, noting that this process is able to charge the molecules of gases in the surrounding air, which in turn,will lead to an ion beam. “The stainless steel transmitter points inside the ionbar receive 5 kVrms high voltage through an armored and electromagnetically shielded high voltage cable. An integrated ground wire in the power cable creates a discharge path from the emitter to the bar channel.”
The Jordanian team tested the purification technology with four 250 W polycrystalline solar modules mounted at a 25-degree tilt at the Renewable Energy Center of the Applied Science Private University in Amman. Performance was compared between natural cleaning and cleaning based on an anti-reflective coating.
After two weeks of testing, the researchers found that the loss of energy production from the PV modules was about 5.93% with natural purification. They said the coating was also about 3.8 times more cost-effective than electrostatic neutralization under the conditions presented in the study.
“However, the loss of coating material after two weeks poses a recoating problem from an economic point of view compared to electrostatic neutralization, where operating costs could be eliminated by developing a fixed mechanism with no moving parts,” the researchers said.
The team claims that the performance of electrostatic cleaning technology could be further improved by improving its internal mechanism.
“Although nanocoating seems economically wiser than electrostatic cleaning, electrostatic cleaning is a promising future for mega-solar power plants located in arid regions because of the reduced impact of harsh outdoor conditions that often require coating, and the possibility of developing a practical mechanism for electrostatic cleaning at lower capital and operating costs,” they they said.
The scientists published their findings “Electrostatic Cleaning Effect on PV Module Performance in Jordan”, published recently Cleaner technology and technology. In March, researchers The Massachusetts Institute of Technology has developed a prototype lab-scale solar module cleaning system that uses electrostatic repulsion to dislodge dust particles and virtually jump off the surface of the panels.