Panel soiling has been a running concern for solar plant owners since the birth of Solar PV industry. India’s present 54GW installed solar assets with rising cost of project’s OPEX multiplied with falling tariff rate, raising major challenges for asset owners in terms of profitability. Scarcity and high water cost in several dry and arid regions of India make wet cleaning unviable. To tackle this challenge a lot of asset owners are now shifting to different cleaning technologies like waterless robotic cleaning, Anti soiling coating , chemical cleaning etc.
Keeping in view the present market challenges, UK based company Solar Sharc® developed an anti soiling coating solution which can be used with retrofitted old modules and also with new solar module glass. This anti soiling coating is of hydrophobic type with a nano coating on the module glass. As detailed below the ASC coating has been tested to IEC 61251 standard,equivalent to 25 years.It will consume 50% less water for module cleaning. The Solar Sharc® coating was tested under the H2020 European funded project ( Fast Track to Innovation) with an investment in testing with a project value of €2,767,439.00. The field trials were conducted by CEA INES in France and the output of the test confirmed that the coating passed the IEC 61251 standard.
Testing of the panels was undertaken in line with the most demanding aspects of:
• IEC 61215:2005 “Crystalline Silicon Terrestrial Photovoltaic (PV) Modules – Design Qualification and Type Approval”
• IEC 61730 2011:1&2 standard “Photovoltaic (PV) module safety qualification –Part 1: Requirements for construction & Part 2: Requirements for testing”.
In a test conducted by Solar Sharc®, two glass substrates (one coated with Solar Sharc®, the other uncoated) were exposed to an Arizona sand solution with 5 layers of sand deposited on top of each other, over a period of 20 hours at 4 hour intervals. In between each deposit, the substrates were baked at 45C. They were then washed with deionised water, and the coated surface took 49% less water to be fully cleaned. It can be noted that one of the substrates coated with Solar Sharc®, sand did not fully adhere as part of the baking process.
In terms of coverage, 1 Liter of Solar Sharc® will cover approximately 144 Sqm. The example below provides an overview of coverage based on 50 Liters:
Though at present Solar Sharc® has a very limited presence in the Indian market, they are engaged in discussions with 4 major players in the Indian PV market. They expect that testing and evaluation of the coating will be implemented shortly with one of these companies. In addition, they are in discussions with an established Indian paint & coating manufacturer with the aim of them becoming an authorized distributor for Solar Sharc® & other PV product Solar Sharc® Lite in the region. They have distributors in Korea & Japan. The products are on test in China, Brazil, Philippines, USA, Thailand, Spain, Belgium, Germany, UK and Peru. They have two BIPV manufacturers based in Europe, one who is testing to integrate into their modules & one who specifies when required under global tenders. The latter one is Onyx Solar who are the world’s leading bespoke BIPV manufacturer and were part of the H2020 funded project for the testing and evaluation of the coating. Over and above these there are a high volume of global customers who are purchasing samples for testing and field evaluation.