Cleaning methods for solar PV systems in Sri Lanka: Economic and environmental evaluations

Abstract

• Evaluates economic and environmental feasibility of manual vs. robotic PV cleaning. • Uses PVsyst simulations, LCOE, and NPV for energy and financial performance analysis. • Manual cleaning offers a 3–4 year payback, outperforming robotic cleaning in most zones. • Robotic cleaning benefits from reduced labor needs but has longer payback periods. • Highlights climate-specific cleaning strategies for Sri Lanka's diverse weather zones. • Rising labor costs and tech advances may enhance the competitiveness of robotic cleaning. Solar energy holds significant potential in Sri Lanka, but the performance of photovoltaic (PV) systems is often compromised by soiling from dust and pollution. This study evaluates the economic and environmental feasibility of manual and robotic PV cleaning methods across Sri Lanka's diverse climatic zones. Using PVsyst simulations with localised economic data, the research models energy generation and performs financial analyses using Levelized Cost of Electricity (LCOE) and Net Present Value (NPV). Environmental assessments further examine soiling effects and cleaning efficiency. Simulations conducted in wet, dry, and intermediate zones reveal that manual cleaning is generally more cost-effective, with a payback period of 3–4 years. Robotic cleaning, while operationally advantageous due to reduced labour dependency and consistent efficiency, requires a longer payback period of 5–7 years without financing and 7–9 years with loans. These findings highlight the importance of climate-specific cleaning schedules and suggest that while manual cleaning is currently more viable, advancements in technology and rising labour costs may render robotic cleaning a competitive option in the future.