Operations and maintenance (O&M) activities are a crucial process in the solar industry. These activities augment the safety and efficiency of solar modules, thereby, ensuring long-term sustainability of projects. External vulnerabilities to a module include dust, pollen, variable temperatures, extreme weather conditions and bird droppings, which can often negatively influence the power generation capacity of solar panels. Poor air quality is predominant in several states of India, while dust storms have also become more frequent in arid regions. These factors need to be countered in order to maintain the original output level of modules. Reduction in solar efficiency is more prominent in arid regions, which are often the sites for large-scale solar projects in India. Cleaning solutions are thus an essential tool, particularly in these regions.
Cleaning technologies are primarily characterised as manual, semi-automatic and fully automatic. In terms of their functioning, they are often defined as water based, electrostatic and robotic, among others. The traditional way of solar cleaning is manual and relies heavily on labour and water resources. Vehicles, pumps and pipelines also form an essential part of the traditional process of cleaning solar modules. The dependence on human labour often leads to inefficiencies in the process, inducing higher costs of O&M. Semi-automatic solutions rely both on robots and labour. However, the dominant segment going forward is expected to be fully autonomous cleaning solutions, which do not entail any manual intervention. Robots themselves determine the ideal time to clean, analysing external factors such as weather and dust storms. The solar module cleaning market in India is expected to grow at a compound annual growth rate of roughly 12 per cent over the next five years. The market size for robotic solar cleaning market is anticipated to grow by $4 billion-$5 billion per year.
Current estimates suggest that 40-50 per cent of greenfield projects rely on manual solutions, 10-15 per cent on semi-automatic on lift and shift models, and the rest on fully automatic solutions. By 2025, 88 per cent of the market is anticipated to transition to fully autonomous solutions, while 12 per cent will resort to manual cleaning. The latter will primarily be brownfield projects, which are already installed. Because of high fixed costs, going for automated solutions may not be feasible for very small projects. At present, only 8 per cent of the market in the country is occupied by robotics. In the second half of this decade, over 70 per cent of the market in India is expected to transition to robotic solutions. In arid regions, however, 100 per cent projects are likely to shift to robotics during this period.
Types and technologies
Robotic solutions also differ among themselves, in terms of technology and functioning. For fixed tilt installations, solutions where the solar panel remains untouched by the robot are utilised. Since they ensure greater safety of the module, these robots are costlier. The market share of such solutions is expected to fall, especially in greenfield projects. In contrast, brownfield projects may continue to find them feasible as long as tariffs remain economical. Robotic solutions also exist for single-axis trackers. These are primarily lightweight in nature. Over 20-30 per cent of the market is occupied by this technology. The third type of technology, a hybrid robotic solution for fixed tilt and single-axis trackers, is likely to dominate the market over the coming years.
Key features include flexible wheels, no damage risk to frames and longer coverage over rows. New robotic technologies, which offer waterless cleaning solutions, are also penetrating the market. These utilise components such as mechanical brushes, standing wave electric curtain systems, heliotex technology, nano-film, cloud computing and internet of things (IoT). In the near term, the solar O&M market can expect further expansion of such automated technologies.
Key growth drivers
Growth and advancements in the solar industry over the past few years have made way for greater demand of robotic and automated cleaning solutions in the market. The demand has been further augmented by the onset of the Covid-19 pandemic. Constraints to movement and mobility reinstated the significant role of artificial intelligence and technology in the industry. Thus, minimising dependence on human labour, while also lowering O&M costs, is an attractive avenue for project developers. Unmanned cleaning machines are also expected to minimise human errors in O&M activities. In addition to saving the costs and time associated with cleaning solar panels, robotic technologies may also provide higher performance outcomes and greater reliability under extreme weather conditions. Consequently, the solar industry can expect a rapid influx of robotic and automated cleaning solutions in the near future.
Primarily, there are four key drivers for robotics penetration in the solar O&M market. First, the scale of operations has risen tremendously in the past decade. For instance, in the 2010-11 period, the largest solar project in India had a capacity of around 1 MW. In 2012, the highest project capacity progressed to 5 MW. At present, however, the size of upcoming solar projects often ranges in the GW scale. The Bhadla Solar Park in Rajasthan is one such project, operating at a capacity of 2.2 GW in a single location. The cleaning equipment and methodology required for a 1 MW project vis-à-vis a 2.2 GW project would differ greatly in terms of their efficiency and reliability outcomes. Cleaning solutions for upcoming large-scale greenfield projects require superior technology, as a result of which non-automated cleaning may no longer be feasible or economical for project developers. Further, a growing number of sites with millions of solar panels are being developed in arid regions, where water scarcity and unavailability of sufficient labour are key challenges. This is expected to accelerate the transition from manual to automatic cleaning solutions.
Second, multiple projects suffer due to non-availability of water. With the rising demand for water and depleting resources, heavy dependence on water for O&M activities is highly risky for developers. This is also reflected in preferences of lenders and regulators, who are less likely to provide backing to such projects. Water-based solutions also create increased vegetation and leave mineral traces.
Third, technological advancements have created a new era of renewable energy development. While robotics is currently used for cleaning, this technology is also adapting to cater to other maintenance activities. The presence of sensors allows robotic solutions to travel throughout the plant and analyse angles that are crucial for structural maintenance of a panel. Real-time data transmission and active inputs from robots can play a significant role in enhancing the safety of a project. Fully autonomous robotic solutions perform effective and efficient cleaning on a daily basis, utilising sensors, machine learning and IoT. Other associated robotic solutions are also expected to come up in the coming months. These may include grass-cutting robots that use a combination of motion sensors, cameras and drones to take care of the security of the plant. This will significantly reduce the manpower requirements in O&M activities.
Finally, price parameters are also expected to drive the transition towards automated solutions. These solutions ensure optimal energy production while saving O&M costs and managerial overheads. Additionally, the cost of automated solutions is expected to fall rapidly as compared to the cost of manual labour. Due to continuous upgradation of technology, the number of robots per MW is also reducing, thereby, supplementing the fall in costs. Over the past few years, the lowest tariffs bid in India have been won by developers that relied on robotics for cleaning. Thus, robotic solar panel cleaning may be an enabler to warrant low-cost bids and ensure greater reliability.
Cleaning solutions are an integral part of solar O&M. While robotic cleaning represents only 1-2 per cent of the total capex of a solar site, it can pose a huge risk if the right solution is not chosen. Real-time observation of breakage of panels, presence of any external threats and absence of essential maintenance components by robots can ensure that the power conversion capability of the solar module is not disrupted. The possibility of immediate recovery from potential threats such as dust storms also holds immense importance.
To conclude, to remain competitive in the market, improving efficiency and lowering costs continue to play a key role. This is driving a significant transition from manual module cleaning towards robotic solutions.
(Based on remarks by Nalin Sharma, Vice-President, Asia and Pacific, Ecoppia, at the Conference on “Solar Operations and Maintenance” organised by Renewable Watch)