Water is a scarce commodity in a country of nearly 1.4 billion people, and the use of water in energy generation is a big concern. The rise of solar and wind generation is significant as they not only curb air pollution but also tend to use less water compared to thermal generation.

That said, solar projects do use some water primarily for cleaning panels. Cleaning of solar modules is a big challenge for developers, especially in arid and dry zones where water is scarce, particularly water that is suitable for cleaning solar modules.

The life of solar modules is usually guaranteed for 25 years, and throughout its life span, cleaning is essential for efficient power generation, which ultimately impacts the bottom line.

Dust particles, bird droppings, and other particulate materials lead to a decrease in energy generation, highlighting the importance of solar module cleaning. While manual cleaning is one of the options, several robotic technologies have entered the market that provides a cost-effective method to clean solar panels as compared to manual cleaning. Some of the more common types of robotic cleaning systems include: module cleaning robots, driving robots, and AI-enabled robots.

Speaking about the latest technologies entering the robotic cleaning market, Aayushman Goyal, senior management, product development at Ganges Internationale, said, “The latest technologies include trolleys that can facilitate movement between two rows in a plant, which will bring down the CAPEX (capital expenditure) significantly. Infusion of thermal imaging cameras with robotic cleaners is another new technology that will shape the future, as it gives plant owners the ability to detect and fix any hotspots that may arise on their modules.”

Authorities have also noticed increased water usage in solar projects. Last year, the Ministry of New and Renewable Energy (MNRE) recommended the efficient utilization of water for cleaning utility-scale solar projects. The ministry said that project developers are currently using too much water to clean solar modules, and they should try and minimize wastage. The ministry also recommended the use of robotic cleaning technology.

Currently, developers have to seek permission from local authorities to get access to groundwater and canals. The lack of water in these dry, arid zones poses a massive challenge for the developers.

According to a 2018 NITI Aayog report, India is suffering from the worst water crisis in its history, and millions of lives are at risk because of it. Currently, 600 million Indians face high to extreme water stress, and the crisis is only going to get worse. By 2030, the country’s water demand is projected to be twice the available supply, implying a severe water scarcity for hundreds of millions of people which count account for an eventual ~six percent loss to the country’s GDP.

The application of robotic cleaning solutions is slowly gaining acceptance, and it becomes more economical when the project sizes increase. The larger the project, the higher the cost of manual labor for panel cleaning which is driving utility-scale developers and solar park operators to opt for automated cleaning solutions.

Several companies, both domestic and international, have started offering robotic panel cleaning solutions to customers. In November last year, Israeli company Ecoppia was chosen by Fortum to deploy its field-proven cleaning solutions across its solar projects in India. Ecoppia has partnered with Fortum to equip its projects in Pavagada and Bhadla solar parks with Ecoppia’s environmentally friendly E4 solution. The Bhadla project is in a water-deficient region and often faces massive dust storms. Ecoppia’s E4 is a fully autonomous robot that uses microfiber brushes to clean the dust from the solar panels. It is designed for large rows of solar panels located in arid and sandy zones.

Speaking to Mercom, Ecoppia’s Vice President of Marketing, Anet Cohen Segev, said that solar companies are moving towards robotic cleaning as the only way to remain competitive in today’s low tariff, low margin times, and to improve O&M practices through automation.

Comparing it with manual cleaning, Segev said, “Unlike manual cleaning, with the robotic solution you have no reliance on labor availability and labor costs, and what’s more important is that cleaning itself is consistent day in day out. Clearly, this is not the case with manual cleaning, and cleaning is not consistent as it may cause hot spots, which will drastically impact the modules’ production rate. With Ecoppia robots, the cleaning is not only efficient and consistent but also water-free and sustainable. No manual cleaning can be done without water.”

Domestic companies and start-ups are slowly gaining traction and attracting investments as the demand for robotic solutions has increased. Recently, the Noida-based clean tech start-up Skilancer Solar received funding from Venture Catalysts. Skilancer Solar specializes in providing a robotic cleaning system which is capable of cleaning solar modules without the use of water and manual intervention. In June of last year, Alfa Ventures, a venture capital fund, along with serial entrepreneur Dhianu Das, had announced an undisclosed investment in Skilancer Solar.

According to Mercom India Research, major developers such as SB Energy (SoftBank), Sprng Energy (Actis), Engie, NTPC, ACME Solar, Rattan India, and Fortum have deployed the solar robotic cleaning systems on their projects. Most of the major developers have robotic cleaning systems installed on projects at solar parks such as REWA, Bhadla, Pavagada.

Speaking on the cost-effective nature of robotic cleaning, Manish Kumar Das, director of business at Skilancer, says, “Robotic cleaning system eliminates three major components of cost which result in higher ROI. The three cost components involved are the water cost, manpower cost, and higher electricity generation due to daily cleaning. To sum this up, the ROI will increase by nearly 15-20% from robotic solar panel cleaning.”

“Approximately 2 liters of water is required to clean a single panel per cycle and typically 3200 panels are installed in a 1 MW plant. Now for every cleaning cycle, approximately 6,400 liters of water is required per cleaning cycle. So, typically 12,800 liters of water per month are saved using a robotic cleaning system. Taking the case of 1 MW installation, the developer can save up to ₹700,000 (~$9778.55) annually,” he adds.

Robotic cleaning does mean capital investments when most developers are cash strapped. Does investing in these new technologies make sense in the long-term? After all, in India, it is ultimately all about the cost.

“Robotic cleaning is the best and most optimized method of cleaning solar panels. I should not deny that the cost of installation of the robotic cleaning system is more than the traditional cleaning. But if we look at the bigger picture where the plants are to be kept functioning for 25 years and if the tariffs are reduced, it will lead to less ROI for any solar power project owner. On the other hand, there are two additional costs involved in the traditional method; one is the labor cost and the second is the water cost. With the robotic system installed, the plant owners can save on labor, water, with the added advantage of the higher generation of electricity,” comments Das.

India is a vast country with varying climatic conditions, and this makes it imperative for developers to take into account all the factors before opting for robotic cleaning. Das added, “Robotic cleaning is perfect for Indian weather conditions when compared to the Middle East where sand storms can cause a massive load of sand to settle on the solar panels where robots cannot be deployed. In the European colder conditions, snow piles up on the solar panels making it very difficult to clean the panels using the robotic system. The best validation of Indian is the sudden influx of major robotic cleaning players in the Indian market.”

In December last year, the Bharat Heavy Electricals Limited (BHEL) issued a tender for the supply of module cleaning systems for 50 MW of solar projects in the state of Maharashtra. The projects are located at Koudgaon, Osmanabad, in the state of Maharashtra.

Earlier, BHEL had floated a tender for the supply, instrumentation, and construction of a module cleaning system for 129 MW of solar photovoltaic projects located at Singareni Collieries Company Limited (SCCL) in Telangana.

Several semi-automated and automated cleaning methods are gradually replacing manual ones with improved efficiency and reduced costs. With low labor costs in India, it might take a while before robotic cleaning completely replaces manual cleaning, but as the costs of these solutions decrease, more developers are opting for this new technology. The scarcity of water will make the move toward waterless robotic cleaning inevitable.

Image credit: Skilancer Solar