Banana leaf wax performance as a coating material to reduce fouling and heat for photovoltaic improvement

Abstract

The growing dependence on limited fossil fuels and their environmental impact drive the adoption of renewable energy, with photovoltaics (PV) being a leading option. However, PV performance often declines due to elevated operating temperatures and surface fouling, especially in tropical climates, leading to reduced efficiency. To address this, coating materials with dual functionalities of cooling and self-cleaning are needed. This study investigates banana leaf wax as a natural coating to enhance PV performance. The wax was extracted using n-hexane, applied via spray-coating, and characterized through light transmittance tests, scanning electron microscope (SEM) imaging, water contact angle (WCA), adhesion analysis, and field trials on PV modules. The wax demonstrated an average WCA of 127°, with a microcrystalline structure supporting hydrophobic and self-cleaning properties. Field implementation showed that a 9 μm wax layer reduced PV module temperature by approximately 5 °C and increased output power by 15-20% under high irradiance (G ≈1200 W/m²). The cooling effect proved more significant than transmission losses, confirming the potential of banana leaf wax as an effective tropical PV coating. Nevertheless, further studies are required to optimize thickness, strengthen adhesion through hybrid formulations, and integrate the material into advanced optoelectronic coatings for sustainable efficiency improvements.