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A Jordanian research team has devised a solar module cleaning technique that uses static electricity to remove dust from panel surfaces. The system has an electrostatic ionizer that reduces the attraction between dust particles and their accumulation in the modules, improving their energy efficiency.
Researchers at the University of Jordan have proposed the use of electrostatic cleaning as an effective method of removing dust from solar panels.
Electrostatic cleaning consists of 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 different electrically charged disinfectants, disinfectants, and cleaners.
According to scientists, the glass in solar modules contains the same number of positive and negative charges, which means it is electrically balanced. However, friction can upset this balance and cause the material to become electrically charged.
“The electric charge will create an attractive force between the dust particles and the glass due to the static charge that causes the accumulation of dust on the photovoltaic modules,” the researchers explained.
The academics proposed the use of an electrostatic ionizer, which uses ions to neutralize static electricity, in order to reduce the attraction between dust particles. They used an ionizer made by British specialist Exair, which could flood the surface of the PV module with a uniform flow of air over its entire length, charged with static-eliminating ions. The ionizer was placed on a 0.2 m axis attached to a screw driven by an alternating current geared motor located on top of the panel.
"The charged surface attracts the right number of positive and negative ions to become neutral," the researchers explained, noting that this process is capable of charging the gas molecules in the surrounding air, which in turn results in rain. of ions. “The stainless steel emitting points inside the ion bar receive a high voltage of 5 kVrms, through a shielded and electromagnetically shielded high voltage cable. An integrated ground wire within the power cable creates a discharge path from the emitter to the bus channel."
The Jordanian group tested the cleaning technique on an array of four 250W polycrystalline solar modules mounted at a 25-degree tilt angle at the Renewable Energy Center of Amman Private University of Applied Sciences. Performance was compared to natural cleaning and anti-reflective coating-based cleaning.
After two weeks of testing, the scientists found that the PV modules had an energy yield loss of around 5.93% with natural cleaning. They stated that the coating was also about 3.8 times more economically viable than electrostatic neutralization under the conditions established in the study.
“However, the fading of the coating material after two weeks posed a coating problem from an economic point of view, compared to electrostatic neutralization, the cost of operation of which could be eliminated by developing a fixed mechanism with no moving parts. ”, the scientists pointed out.
The group claims that the performance of the electrostatic cleaning technique could be further improved by improving its intrinsic mechanism. “Although nano-coating seems cheaper than electrostatic cleaning, electrostatic cleaning has a promising future for solar mega-plants in arid regions, as it is less affected by harsh outdoor conditions, which require frequent coating, and by the possibility of developing a practical electrostatic cleaning mechanism with lower capital and operating costs,” they say.
The scientists published their findings in “Electrostatic cleaning effect on the performance of PV modules in Jordan,” recently published in Cleaner Engineering and Technology . In March, scientists at the Massachusetts Institute of Technology developed a prototype lab-scale solar module cleaning system that uses electrostatic repulsion to cause dust particles to flake off and virtually jump off the surface of the panels. |
