High-Voltage Vehicle Integrated Photovoltaic System Concept and Demonstrator Truck

Certain commercial vehicles feature large roof areas that can be easily equipped with lightweight photovoltaic (PV) modules to harvest solar energy. Typically, heavy commercial vehicles (>12 t trucks and semi-trailer) can be fitted with an installed photovoltaic power of 3 kWp to 7 kWp with today’s mainstream cell technologies integrated on the roof, and harvest significant amounts of energy. Therefore, a high voltage photovoltaic system can significantly reduce amount and the cross-section area of the cables, and therefore cost and weight. This is why we propose a high voltage photovoltaic system concept for commercial application. The difference to conventional automotive high voltage systems, which are controlled by a central unit, is that within the photovoltaic array, high voltage is present whenever the PV modules are illuminated, and hence need to be considered as energized at all times. To comply with safety standards and reduce the risks linked to high voltages (e.g. after an accident), we present a smart junction box with integrated disconnector that automatically separates the serial connection of the modules in order to lower the voltage into the range of safety extra-low voltage. The developed VIPV system is able to feed in solar energy during operation and in standby mode. We present a 15-t demonstrator truck, a Framo E-165, equipped with the abovementioned VIPV system and show yield calculations based on an energy yield model.