Researchers Develop Self-Cleaning Solar Panel Coating
A team from the Indian Institute of Technology Jodhpur has reportedly developed a new coating technology that can self-clean solar panel surfaces. According to reports, the coatings are transparent, scalable, durable and superhydrophobic, capable of self-cleaning with very little water and reducing dust accumulation.
About the Coating
The superhydrophobic coating reportedly has excellent self-cleaning properties and exhibits no transmittance or power conversion efficiency loss. Accelerated laboratory-scale tests reportedly showed that the coating also has mechanical and environmental durability.
Ravi K R, Head of Department of Metallurgical and Materials Engineering at IIT Jodhpur, explained that the solar panel manufacturing industry claims to operate at 80% to 90% efficiency for 20 to 25 years. However, dust and sand deposits can reduce performance and, depending on location and climate, solar panels can lose 10% to 40% efficiency within just a few months.
He added that some of the methods currently used to clean the solar panels are expensive, inefficient and have various practical problems in continuous use that can cause irreversible damage.
“The role of academia and industry is essential to implement this technology for real-time applications. The relationship between academia and industry is not just technology donor-recipients but interactive, collaborative, and participatory, valuing each other's roles and contributions to bring about research production integration,” he said.
“Therefore, our research team wants to work closely with industry partners to bring this easy-to-clean coating technology to the PV market and mass-produce it for wider benefit.”
Looking ahead, the team plans to study the durability of the self-cleaning coating in real-time in different regions of the country, including arid and semi-arid desert regions, coastal regions and rural and urban areas. They also want to investigate the various recoating options for damage caused during usage.
Other researchers on the project included Meignanamoorthi G, Project Assistant, and Mohit Singh, Research Scholar and Prime Minister's Research Fellow (PMRF), Department of Metallurgical and Materials Engineering, IIT Jodhpur.
ITT Jodhpur has reportedly applied for a patent for the coating technology.
Recent Solar Coating Research
At the end of last year, a team from the University of Michigan announced that they have created a coating for solar panels to reduce snow and ice accumulation and improve productivity in cold climates. The clear coating, which can be sprayed or brushed on in cold weather, reportedly enabled panels to generate up to 85% more energy in tests.
According to the release, the coating consists of PVC or PDMS plastic and silicon or vegetable-based oils. The current formulation keeps sheds ice and snow accumulation for up to a year. Using the lab’s previous research, the team recognized that low interfacial toughness and low adhesion strength were key to ice-shedding coatings.
Researchers utilized a very rigid PVC plastic for low interfacial toughness and mixed it with a small amount of vegetable oil to create low surface adhesion. According to the release, a second formulation with PDMS plastic and silicon-based oil worked equally well.
The coating was tested at a solar field in Fairbanks, Alaska, in collaboration with the University of Alaska. These panels were monitored by automated cameras for about two weeks, with tests showing that the coated panels had an average snow and ice coverage of approximately 28% over an entire winter season. Uncoated panels had an accumulation of about 59%, in comparison.
Then, in March, researchers from Chiang Mai University in Thailand reported that they have developed a new antireflective, hydrophilic and photocatalytic coating for solar panels. Using this coating, scientists were able to increase the panels’ power yield by over 6%.
According to the research, photovoltaic panel cover glass is highly transparent but has a natural reflectance. One way to increase the panel’s effectiveness would be to reduce the optical loss and natural reflectance with an antireflective coating.
To achieve this, researchers used a “simple and inexpensive” sparking process to produce an AR film. The developed method uses basic equipment that can be operated in ambient environments without a high-vacuum system. Additionally, no toxic waste is produced from any chemical precursors or agents.
For the sparking process, researchers used 0.25-millimeter titanium wire with a 99.5% purity, supplied by United Kingdom-based Advent Research Materials Ltd. The wires were cut, aligned with a gap of one millimeter between the anode and cathode and then “sparked off” with a high DC voltage of around 3 kilovolts discharged from a 24-nF capacitor.
During testing, researchers looked at reflectiveness, surface topography, hydrophilicity, photocatalytic properties and the coating’s anti-soiling properties.
According to the study, the average power difference per day was 5-9% between the coated and uncoated panels. Overall, an average power gain of 6.62% due to the coating was reported over the entire study period.
The highest value difference showed coated panels operated with a power yield of 14.22% more than the uncoated panels. This result was reportedly due to rainy weather, allowing the coating to produce more power by light entrapment, and the super-hydrophilic property of the coating allowed less dust due to rain to cover the panels.
More recently, earlier this month, it was reported that a research team from the University of Helsinki in Finland is developing thin films needed to handle new types of halide perovskite solar cells. This coating technique reportedly provides increasingly affordable solar cells, enables their integration into objects and promotes the transition to renewable energy.
For his master’s thesis, Doctoral Researcher Georgi Popov chose the topic of halide perovskites and their atomic layer deposition (ALD).
The university reports that coatings produced through ALD are used in roughly 30% of silicon-based solar panels. Adapting this technique to perovskite solar cells, the ALD group headed by University of Helsinki professor Mikko Ritala achieved promising results, with the coating forming a uniform and comprehensive layer even on rough surfaces.
While the work currently being carried out is basic research, developing recipes and experimenting with small surface areas, the technique is reportedly applicable to large-scale production. China manufactures 80% of solar cell, as well as producing industrial-scale ALD devices, allowing them to easily adjust equipment to create the ALD-coated solar cells.
Additionally, a University of Helsinki Department of Chemistry alum works as for the leading Chinese manufacturer of ALD equipment, which the university said gives the department a solid grasp on where the field is going. It reports that ALD equipment used to produce silicon-based solar panels can also be expanded to produce next-generation solar cell materials.