Snow melting on photovoltaic module surface heated with transparent resistive wires embedded in polyvinyl butyral interlayer

Abstract

This paper presents a novel surface heating system that has been developed to remove snow and icing accumulating on the photovoltaic (PV) module surfaces in snowy regions. The design was created by laminating the transparent resistive wires onto the module surface along with a second-module glass using an interlayer material called polyvinyl butyral (PVB). To minimize energy consumption, the heating wires were placed on the upper and lower halves of the module surface in discrete segments. The objective of this work is to examine the actual performance of the surface heating system and to assess its suitability for snow removal in terms of energy and economy in comparison to the mechanical stripping method. An experimental measurement and recording system has been established to test the snow melting performance at different inclination angles of the design and to investigate its effect on annual energy production. Heated PV modules were placed on the mounting system with inclination angles of 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees, and 50 degrees together with two standard modules having equivalent properties. Each module in the test system was connected to the grid through a micro-inverter. The electrical energy required for the heating system was provided from the AC grid. The main electrical specifications of the design were measured by utilizing a commercial simulator device before and after lamination and they were used for validation of the efficiency loss. Test results show that the components used in the design led to a reduction of approximately 4.9% in the efficiency of the module. The experimental results obtained under the outdoor conditions show that annual performance loss varies between 5% and 10% depending on the angle of inclination and the differences between modules. In addition, it is observed that the heated module frame makes the fall of snow and the water drainage difficult in all tilt angles and under test conditions. However, when the heating system is used together with high inclined modules, it is demonstrated that energy savings could reach values up to 38% owing to the heating of the module surface piece by piece. Based on economic viability analysis results, it could be concluded that the surface heating method is cost-effective when it is compared to the mechanical stripping method as it only uses electricity that is already available. However, from the financial perspective, it is concluded that the design is inherently expensive in its current form in comparison with a standard module and not financially feasible because it increases the payback time.