Materials design and discovery: Potential for application to soiling mitigation in photovoltaic systems

Abstract Materials science has been changing. The era of “trial-by-error” development is being redirected toward revolutionary “materials-by-design” methodologies that guide experiments to discovery of new or overlooked materials. This “new approach to science” meets increasing demands to develop or improve modern technology over significantly shorter timescales. One such current, critical technology need is preventing surface soiling that can severely limit the performance of photovoltaic systems. Restorative approaches, such as washing or mechanical cleaning, are effective. But they can add significant cost or use limited resources such as water or labor. Preventative approaches would be preferred. But the development of special coatings that not only inhibit the accumulation of particulates on the surface and also can enhance anti-reflection of that module front surface has led to limited successes over the last several decades. That optimal coating (i.e., having 20- to 30-year durability along with the anti-soiling, environmental, low-maintenance, cost, and optical requirements) is not yet realized. This paper reviews and examines the recent approaches to materials design and discovery. The possible application and viability of these novel techniques for the potential development of new or improved coatings that meet the module surface requirements for soiling mitigation are examined. This includes ensuring that the maximum number of incident photons in the desired wavelength-range are transmitted to the glass (or other top encapsulation material) and to the solar cells in the module. Specifically, first-principles calculations and theory are evaluated in order to search for the fundamental atomic arrangements capable of yielding desirable functionalities for this application. The purpose is to establish a basis for using these evolving materials-design methodologies for this specific PV materials reliability issue. A first approach is proposed with initial evaluation regarding materials design and discovery targeted towards anti-soiling in photovoltaic systems by identifying and investigating the key functionalities required for establishing the available viable coatings base.