Solar photovoltaics on the move
Neel Patel defended his PhD thesis at the Department of Mechanical Engineering on October 22nd.
As the world races to reduce greenhouse gas (GHG) emissions and combat climate change, the electrification of road transport has become a crucial part of the solution. Yet, electric vehicles (EVs) can only be truly sustainable if the electricity they use comes from clean, low-emission sources. This PhD research of Neel Patel shows that integrating solar photovoltaic (PV) technology directly into vehicles鈥攌nown as vehicle-integrated photovoltaics (VIPV)鈥攐ffers a promising path toward greener mobility. By allowing cars to generate their own solar energy, VIPV could reduce the environmental impact of transportation and help balance the energy demands on the electric grid.
Efforts to cut human-made GHG emissions are being pursued across many sectors鈥攅nergy, construction, industry, and especially transportation. Within this transition, renewable energy technologies like wind and solar have become central to decarbonizing electricity generation. In transport, EVs have emerged as a cleaner alternative to combustion engines. However, their effectiveness depends on how the electricity used to charge them is produced. Integrating PV systems into vehicles could make EVs even more sustainable by enabling them to generate part of their own power directly from sunlight.
VIPV systems consist of solar modules integrated into various parts of a vehicle鈥檚 body, such as the roof or hood. Depending on the available surface area, these modules can produce anywhere from a few watts to several hundred watts of power. The electricity generated is stored in the vehicle鈥檚 high-voltage battery through a smart energy management system that includes components like maximum power point trackers (MPPTs), a buffer battery, and DC-DC converters. This solar energy can then be used to power the car鈥檚 motor or auxiliary systems.
Challenges on the road to integration
Despite major advances in solar technology and efficiency, incorporating photovoltaic systems into vehicles remains a technical challenge. Unlike fixed rooftop installations, a moving vehicle constantly changes position, orientation, and exposure to sunlight. As a result, the solar irradiance received by each module varies continuously. Additional challenges arise from the extra weight and aerodynamic drag caused by the integrated panels, which can slightly increase the vehicle鈥檚 energy consumption. Managing these dynamic conditions requires a highly responsive energy management system capable of optimizing power flow in real time.
Another source of complexity lies in predicting system performance. While stationary PV systems can be modeled with relatively simple assumptions, VIPV setups behave differently. Their thermal and electrical performance depends on factors such as driving speed, direction, and temperature fluctuations. These conditions make it difficult to rely on traditional models, prompting the need for new simulation methods and experimental validation.
Exploring feasibility and performance
This research of examines the performance of VIPV systems from multiple perspectives. It explores the current technological landscape and evaluates how effectively integrated solar panels can contribute to a vehicle鈥檚 total energy supply. Through simulations and real-world data, the study investigates how much energy a vehicle can realistically generate, how system components such as converters and trackers perform, and where energy losses occur.
In addition, the thermal behavior of solar modules integrated into vehicles is analyzed to understand whether models developed for stationary systems can accurately represent the operating conditions of moving vehicles. The study also compares energy yield predictions from simulation tools with actual measured data to identify the causes of discrepancies and improve modeling accuracy.
The future of solar-powered mobility
Vehicle-integrated photovoltaics represent a compelling opportunity to make electric mobility even more sustainable. While significant challenges remain in design, modeling, and energy management, the findings of this research show that VIPV technology can play an important role in reducing the carbon footprint of transportation. As solar and vehicle technologies continue to advance, cars capable of generating part of their own energy from sunlight may soon become an everyday reality鈥攑utting renewable power truly on the move.
Title of PhD thesis: . Supervisors: Prof. Ang猫le Reinders, and Prof. Uwe Rau.