In a Series Hybrid Solar Vehicle, the Photovoltaic Panels PV concur with the Electric Generator EG, powered by the Internal Combustion Engine ICE, to provide electric energy to the battery pack B or to the Electric Motor EM, through the electric node EN.
The electric motor EM can either provide the mechanical power for the propulsion or restore part of the braking power during regenerative braking (working as Electric Generator EG). In this structure, the thermal engine ICE is sized for a mean load power and works at constant power Pav corresponding to its optimal efficiency, with reduced pollutant emissions, high reliability and long working life. The electric motor EM can reach a peak power Pem>Pav, in order to satisfy the vehicle power demand. On the other hand, in this configuration the energy flows through a series of devices (ICE, generator, battery pack, electric motor, driveline) each with its own efficiency.
The insolation on horizontal PV panels is estimated by using a solar calculator developed at the US National Renewable Energy Lab, for four different US locations, ranging from 21° to 61° of latitude, based on real conditions (i.e. considering clouds, rain etc.) measured in the period 1961-1990.
In this first version of the simulator, the comparison between the hybrid solar vehicle and the conventional vehicle is performed in simplified way, assuming that the ICE works always at its optimum efficiency in Hybrid Solar Vehicle, while it works at the 75% of this value in the conventional vehicle, where the ICE must work also in different operating points with lower efficiency. We also assumed no differences in the net solar energy during parking and driving modes, and no energy degradation in the battery pack. The year savings are estimated considering the use of the hybrid solar vehicle in 300 days per year.
A more advanced version of the simulator, also considering weight, costs and including the integration of the dynamic vehicle model over a given vehicle mission profile, will be available soon.