Automated cleaning of solar panels is a revolutionary concept. Automated cleaners provide periodic maintenance of solar panels in extreme conditions, thus reducing the downtime and improving generation. These are, however, fairly expensive and require a large amount of water, which is scarce in many solar-rich regions. Continuous research and development is being undertaken by global agencies in this fledgling segment to make such solutions more cost-effective and energy efficient. For example, Norway’s independent research organisation SINTEF (The Foundation for Scientific and Industrial Research) and Hungarian company ProDSP Technology have jointly developed a solar panel cleaning robot. It is a multifunctional device that consumes at least one order of magnitude less water than similar technologies. The robot does not use traditional cleaning agents. Instead, it uses mist-like micro-droplets of water that are sprayed on the panel and then cleaned with the help of a micro-cleaning pad, effectively removing contaminants.
The micro-cleaning pad installed in the robot is based on a self-developed wipe-reel that cleans surfaces easily and uses a special microfibre textile, which is effective in removing various types of particles. The researchers developed a variety of micro-cleaning pads, chemicals and air pressure applications after studying various types of contaminants before zeroing in on the one that was the most effective against a range of pollutants. They have also developed methods of controlling the pressure exerted by the robot’s cleaning arm. Since even small scratches can reduce the efficiency of solar cells, it was vital that the robot does not scratch the sensitive glass surface, thus reducing the wear and tear of the panels to a bare minimum.
These robots are autonomous. They do not require energy feed cables, and use less water for cleaning as compared to other methods, making them ideal for use at remote locations with limited water supply, such as the Middle East. Further, since they do not use traditional cleaning agents and hence have no effluent discharge, they will not adversely affect land or nearby water sources, thus having a negligible adverse effect on downstream agricultural and industrial lands.
However, there are a few challenges and issues that this bot-based solar panel cleaning device needs to overcome. One of the most important issues is its integration with existing automated maintenance solutions, which rely on automatic ticketing and manual cleaning. Preprogramming the robot to undertake scheduled maintenance or unscheduled maintenance in case of an emergency may pose a challenge and hence have considerable cost implications. Further, with more sophisticated technologies being developed in the operations and maintenance space, this integration may call for a ground-up development of a new solution, which will drive up costs, at least in the short run. Apart from plant automation, this technology calls for a high level of cybersecurity, given that its integration with the overall plant supervisory control and data acquisition/distributed control system will be on a dedicated intranet or the internet. The latter being used predominantly, cybersecurity concerns assume greater significance, and lead to increased costs. Another issue that the technology is facing is the replacement of manual cleaning, which is quite cheap and effective in countries like India. This is because of the abundance of unskilled and semi-skilled labour in the country. Therefore, the cost economics may prove to be a hurdle in the adoption of this technology in India and similar markets.
This solar panel cleaning robot is still under study and has only been deployed on a pilot basis in Budapest and Hungary. Given the global impetus to install solar energy plants, the robot has excellent prospects of commercialisation. The frequency of cleaning, and the use of the robot, may depend on the location of the solar plant; for instance, solar plants in deserts need to be cleaned more frequently and could involve removing everything from sand to bird droppings. Given its effectiveness in dealing with different types of contaminants, automated cleaning has a wide applicability in solar projects in different areas of the world. Also, considering that India is a water-stressed country, this robot can be of great assistance in improving the cleaning processes of solar plants. If governments could incentivise the use of this technology, it could lead to better prospects of commercialisation.