European researchers evaluate power generation from on-board photovoltaics
Jan 17, 2023
A team of researchers from Ukraine, Latvia and Slovakia evaluated the impact of vehicle integrated photovoltaics (VIPV) on electric vehicle range, according to foreign media reports.
The researchers used a 2017 Volkswagen e-Golf 7 series electric vehicle in Kiev to determine the range of the electric vehicle after a single full charge using solar energy and to compare the results of a fixed VIPV system with a single-axis tracking system.
The team determined that the car had a usable roof area of 1468 mm x 1135 mm. Based on these dimensions, the researchers concluded that the roof could accommodate two 120 W solar panels and a 50 MW monocrystalline module from Chinese manufacturer Xinpuguang. The researchers connected the three panels in parallel to achieve a maximum power of 257.92 W.
The researchers then calculated the photovoltaic power production for the usual days in January, April, July and October. Based on vehicle test data from the New European Driving Cycle (NEDC) and the US Environmental Protection Agency (EPA), the researchers compared the extra mileage an electric car could travel using solar power. The researchers assumed that the solar panels would only charge the electric vehicle battery while parked.
The results showed that a fixed VIPV system could generate 1,587 kWh of electricity in July, allowing the EV to travel 7.98 km according to EPA standards and 12.64 km according to NEDC standards. "This is 3.99% and 6.32% of the maximum range when the battery is fully charged, respectively," the researchers said. " In January, the stationary system generated 291 kWh, or a range of 1.55 km (EPA) and 2.32 km (NEDC), which is 0.77% and 1.16% of the maximum range, respectively.
In summer, the tracking system produces the same amount of energy as the stationary system, but in spring, autumn and winter the tracking system is more productive. the best results were obtained in January, when the electric vehicle could travel 3.01 km (EPA) or 4.52 km (NEDC), which corresponds to 1.51% and 2.26% of the maximum possible range on a single battery charge, respectively. The researchers note that the actual advantage may be somewhat lower due to a number of limitations.
In January, the researchers said, the tracking VIPV system provided an additional 1.46 - 2.2 km of power to the EV. The levelised cost of electricity (LCOE) of this solution, however, is 40% higher than that of a fixed-tilt system. Calculations show an LCOE of $0.6654/kWh for a zero-tilt PV system and $1.1013/kWh for systems with 20 or 80 degrees of tilt. payback times for each system are 5.32 and 5.07 years respectively.
The researchers concluded: "Sun-tracking roof platforms require significantly higher initial investment outlays and are more difficult to install. Given the small difference in payback period, the driver of an average electric vehicle would not need to adjust the tilt to be satisfied with the system."
