Colloquia

Summary

Integration of solar panels on or in vehicles can contribute to exhaust gas reduction in the transport sector, enhance driving range, lower charging frequency, and reduce utility grid usage. This research aims to forecast the energy production of vehicle-integrated photovoltaic systems on trailer trucks, allowing to compare the energy production of solar panels on the lateral sides of the trailer with solar panels on top. The research specifically focused on the effect of shadow on energy production. A dynamic simulation model was developed that can forecast the energy production per trailer side for any route through Europe up to a week in advance, applying user input such as departure location, departure time, end location, and number of PV modules per trailer side. The effect of shadow is simulated using two environmental scenarios: driving on (1) motorway and in (2) urban areas. For each scenario, a database containing shadow heights cast by surrounding objects was created by means of 3D simulations to quantify shadow range, with date, time, and orientation as variables. Shadow simulations have been validated using irradiance measurements by means of irradiance sensors installed on an actual truck which drove 186 km from Genk, Belgium to Reims, France.

Simulations of two routes of c. 205 km through the Netherlands and Spain have been performed. First, simulations were performed without incorporation of shade effect. The simulation model forecasted an energy production of 3.9 kWh and 6.0 kWh by the photovoltaic systems on both lateral sides of the trailer (16 PV modules) during a winter day for the Netherlands and Spain, corresponding to 19 Wh/km and 29 Wh/km respectively. The lateral photovoltaic system produced 3.2 and 1.6 times as much energy as compared to solar panels on the roof (8 PV modules). In the summer this ratio is lower than 1. On overcast days, the energy production of the solar panels on lateral sides of the trailer is always slightly higher than the energy production on top.

A simulation including shade effect was performed for four days: 21st of March, June, September, and December. In contrast to shadow on June and September 21, shadow on December and March 21 is long and reaches both lateral side and top of a trailer. The shadow reduces energy production by 64% and 52% respectively compared to a shadowless route. Excluding shade effect, the simulation model performed with a root mean square error of 0.23. Incorporation of shadow effect showed insufficient correlation with the irradiance measurements. A more extensive measurement dataset should be created to provide more detail on the effect of shadow on energy production.