Photometric and Regulation-Based Assessment of an Integrated Lighting System for a Solar Race Car

Solar electric race cars require auxiliary systems that satisfy safety-related lighting requirements while maintaining low mass, compact integration, and minimal power demand. This paper presents the photometric and regulation-based assessment of the integrated lighting system of the Neumann Solar race car, a fully custom vehicle designed from the ground up for long-distance solar competition. The work addresses the development and evaluation of the vehicle’s daytime running, indicator, stop, and side signaling lamps under strict geometric, aerodynamic, and energy-efficiency constraints. Since the lamp assemblies and their protective covers were specifically designed for this vehicle, design conformity was evaluated through analytical pre-validation using regulation-based visibility, luminous-intensity, and chromaticity criteria. The methodology combined installation geometry analysis, directional luminous-intensity calculations based on LED radiation characteristics, evaluation of LED count and PWM duty cycles, and estimation of cover-related optical losses using Fresnel-based reflection analysis. The results showed that the selected configurations satisfied the evaluated BWSC and regulation-derived design requirements in the critical reference directions while preserving compact integration and low auxiliary power demand. This study demonstrates that regulation-driven and energy-conscious lighting design can support both road safety expectations and the efficiency objectives of sustainable solar vehicle development.