Fraunhofer ISE is partnering with the Fraunhofer Institute for Transport and Infrastructure Systems and four trucking companies to develop vehicle-integrated solar systems that can help reduce carbon emissions from the transport industry.
As part of the research, Fraunhofer ISE has equipped several trucks with sensors that record how much solar energy they are exposed to in real world use. That research suggests for each square meter of surface area, 150 kWh of electricity can be generated each year. Translate that to the surface area of a typical cargo trailer — about 32 square meters — and the result is enough electricity to power an electric vehicle a distance of 5,000 kilometers or more a year. 
Over the next three years, the research teams and their commercial partners will design and test vehicle integrated solar modules for electric cars and heavy duty vehicles, with an emphasis on solar modules and power electronics, as well as manufacturing techniques for PV applications.
Using an existing production line from German manufacturer Sunset Energietechnik, they will develop the manufacturing techniques needed to produce lightweight solar modules. Integrated solar for vehicles presents some challenges, particularly keeping the weight of such systems low to avoid reducing payload significantly. The target weight for commercial vehicles is no more than 2.2 kilograms per square meter.
In addition, the systems must be robust enough to withstand the constant pounding trucks experience during normal use. The benefits of integrated solar include powering refrigeration units that normally use diesel generators and a potential auxiliary power source for electric delivery vans.
“Calculations show that 4,000 to 6,000 kilometers of additional driving range per year are possible.” And so, step by step, the renewable energy and electric vehicle revolutions are moving forward, each one supporting the other in replacing fossil fuels with sustainable alternatives.
Reference- PV Magazine, Clean Technica, Fraunhofer ISE Website & PR