Techno-Economic Assessment of Soiling Losses and Mitigation Strategies for Solar Power Generation

The light-collecting surfaces of solar power systems cover areas of more than 3,000 km2 worldwide, with PV modules accounting for the majority. An often-neglected problem is the contamination of these surfaces, so-called “soiling,” which leads to significantly reduced energy yields, especially in high-insolation arid and semi-arid climates. Indeed, an inadequate soiling mitigation strategy in high solar-potential and soiling-prone locations such as China, India, or the Middle East can cancel out in few weeks the impressive progress in solar cell and CSP efficiency made in recent decades. Currently, there is no one-solution-fits-all to the problem of soiling due to its site-specific and seasonal variability, differences in local energy costs, and the availability and costs of resources required for cleaning, such as water or labor. Indeed, frequent cleaning can increase the energy generation costs and water consumption dramatically, leading to a need for water-less and inexpensive soiling mitigation technologies. Our analysis indicates that in addition to optimized cleaning plans, automated cleaning machines, anti-soiling coatings, tracking system modifications, PV module design, improved soiling monitoring, and site adaption can be economically feasible and effective solutions to reduce the negative impact of soiling. Other technologies like electrodynamic screens or dew mitigation need further research and development to improve functionality and become economically relevant for large-scale application.