Robots at Work

Emerging solutions in the module cleaning space

In terms of growth, solar power continues to dominate other renewables. The year 2019 witnessed the installation of an unprecedented level of solar capacity. As per REN21, about 115 GW of solar generation capacity was added during 2019, registering a growth of 22.5 per cent over 2018. The total installed solar PV capacity across countries stood at 627 GW. Around 18 countries added at least 1 GW of new capacity, up from 11 countries in 2018. Further, at least 39 countries had a cumulative capacity of 1 GW or more, up from 31 countries one year earlier. Countries that ranked among the top 10 for new solar PV installations added 3.1 GW or more. During the past year, corporate purchasing also expanded considerably. The impressive growth of the solar PV industry has, in fact, facilitated the progress in related markets. The market for solar panel cleaning is one such area which has witnessed tremendous growth in terms of market value.

According to Research and Markets, the efficiency of solar panels can diminish by 20 per cent in domestic installations and 60 per cent in commercial installations. Efficiency loss of this volume is significant enough for solar plant developers to consider investing considerably in robust cleaning, and demonstrates the need to have an efficient and cost-effective system in place to clean solar panels. Some of the most basic cleaning systems are water based, electrostatic and robotic.

In India, robotic cleaning gained traction in 2019, when the Ministry of New and Renewable Energy issued a letter recommending prudent use of water for cleaning utility-scale solar projects. To this end, the ministry recommended the use of robotic cleaning technology, which uses less water for cleaning solar projects.

The uptake of robotic cleaning technology is increasing and is expected to surpass the traditional manual cleaning systems. Further, the introduction of new and modern technologies such as advanced robotics with artificial intelligence and autonomous solar panel cleaning will help the technology compete with manual-based robotic cleaning methods in the coming years.

The use of robotic cleaning solutions becomes more cost economical with increase in project size. The larger the project, the greater the cost of manual labour. Taking this into consideration, most utility-scale project developers and solar park operators have started opting for automated solutions. Another emerging solution to the challenges of manual cleaning is water-free robotic panel cleaning, which results in significant savings in vehicle, water and labour costs. Water-free autonomous technology can also help in reducing soiling losses by cleaning faster and producing higher quality results than manual cleaning methods. Normally, traditional manual cleaning is done once in 15 days and is thus not the most effective solution. In contrast, robotic solutions can clean solar panels every day, or on demand, without any substantial human intervention.

According to Research and Markets’ report titled “Global Solar Panel Cleaning Systems Market Size, Market Share, Application Analysis, Regional Outlook,

Growth Trends, Key Players, Competitive Strategies and Forecasts, 2018 to 2026,” the solar panel cleaning systems market is estimated to grow at a compound annual growth rate of 7.5 per cent during the forecast period from 2018 to 2026.

In a bid to capitalise on the opportunities in this space, several local as well as global players have entered the market for module cleaning systems.

Recent developments

The leading solar panel cleaning system manufacturing companies are Heliotex LLC, Ecoppia, Ecovacs Robotics, Parish Maintenance Supply, Kärcher UK Ltd., BP Metalmeccanica s.r.l., Solar Cleaning Machinery, Indisolar Products Private Limited, AX System, Vip Clean s.r.l., IPC Eagle, Integra Global co., ltd., IDRIS Automation, Unger Germany GmbH and Enel Green Power S.p.A. A number of domestic and international companies are offering these solutions in India. Tel Aviv-based Ecoppia was one of the early entrants in the Indian dry robotic cleaning space. The company’s early clients included NTPC Limited (5 MW plant in Dadri), for which the module cleaning company provided a fully automated water-free solar panel cleaning system. The device was attached to the panel and moved over the surface, clearing the dust with microfibres.

In fact, Ecoppia has been providing its water-free cleaning robotic solutions to a number of utility-scale solar project developers in the country. In 2016, Solairedirect India signed an agreement with Ecoppia to deploy the latter’s automated cleaning solution in its 168 MW project in the Bhadla Solar Park. With this, Solairedirect expected to save over 1.5 billion litres of water and cut down on the production loss associated with the maintenance of panels. In mid-2018, Ecoppia signed an agreement with SB Energy to install around 2,000 robots across its five project sites at the Bhadla Solar Park (Phases III and IV) in Rajasthan, which is in a water-deficient region and often faces massive dust storms that increase panel soiling, resulting in reduced energy output. These robots work independent of human interference and can be remotely operated through a cloud-based control system. It is estimated that Ecoppia’s water-free technology can save over 2 billion litres of water over the solar plant’s 25-year operational life.

In 2019, Ecoppia won a contract from Fortum for 427 MW of solar projects, located in Pavagada and Bhadla. The company also launched a fully autonomous solution for single-axis tracker installations called Ecoppia T4. The technology is compatible with all trackers and module types, including frameless and thin-film panels. It has a cloud-based software which uses advanced machine learning and internet of things capabilities to clean the solar panels on a daily basis. Ecoppia T4 cleans the module using soft microfibres and controlled airflow. In fact, the autonomous robot can travel to neighbouring trackers over dedicated bridges on its own, with the help of integral sensors. The first commercial deployment of the product was at a large installation in the Middle East. Once online, the system would use over 100 cleaning robots to ensure that soiling and dust storms do not impact production levels. In December 2020, Ecoppia signed an agreement with Azure Power to provide its solutions for a 450 MW solar project. The project is at an advanced stage and is scheduled to be operational by the first quarter of 2021. US-based SunPower is another company that offers minimal-water usage-based robotic cleaning systems in India.

Among domestic players, Kapson Tekno Engineers offers solar cleaning rollers made of scratch-resistant microfibre stretchable cloth. Its solar cleaning rollers, iXC-12 robot, travel on a track specially created on the mounting frame. Once these tracks are installed, they take care of uneven landscaping, uneven panel installations and gaps between the panels. Although small, domestic companies are gaining traction due to the growing demand for these solutions, and, in turn, attracting investments. In January 2020, Venture Catalysts, an integrated incubator, invested an undisclosed amount in Noida-based Skilancer Solar, a solar module cleaning solutions provider. Skilancer Solar manufactures centrally controlled, self-powered robotic arms for automatic cleaning of solar modules. Earlier, Alfa Ventures, a venture capital fund, along with entrepreneur Dhianu Das, had announced an investment in Skilancer Solar.

A number of semi-automated cleaning methods are gradually replacing the manual ones due to improved efficiency and better costs. For instance, Mumbai-based Inspire Clean Energy has designed a cleaning brush that effectively cleans a module with minimal water. In fact, it uses only about 300 ml of water to clean a module as against 5-7 litres used in manual cleaning.

Key challenges and future outlook

While many robotic module cleaning products have entered the Indian solar market, the widespread use of such products is yet to be seen. In a price-sensitive market where operations and maintenance (O&M) players have to work on thin margins, there is still greater use of cheap and manual methods for module cleaning which are water intensive. These water-guzzling manual methods are still being used as there are a few challenges with robotic cleaning that need to be addressed. One, there is the issue of unavailability of spare parts. Two, robotic cleaning becomes difficult for rooftop solar installations because these products tend to be heavy. Three, a big caveat with robotic water-free cleaning, in particular, is that it can only be used for cleaning dry sand. For wet sand, water-based cleaning methods are necessary. The development of home-grown module cleaning technologies is a big positive for the Indian solar industry, which has been highly dependent on the Chinese market for even small equipment. Indian technology providers have worked towards making these products cost competitive. Going forward, the aim should be to encourage O&M service providers to use such technologies.


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