Mobile solar power: Cars, vans and trucks could cover a large part of their electricity needs via solar cells on the roof or hood – even here in Central Europe, as analyzes show. Accordingly, an electric car can generate up to 50 percent of its own electricity using such solar modules. Even electric trucks can increase their range by up to 15 percent using photovoltaics. Such PV vehicles would also be a real relief for the electricity grid and the climate: they could save up to 15 terawatt hours of electricity and 2.7 million CO2 across Europe, as the researchers report.
Solar power is also established here: despite Central European weather conditions, photovoltaics have proven to be worthwhile. But solar modules on vehicles have so far been seen as more of an experimental gimmick. Researchers have already developed solar modules that are integrated into the body and feed their electricity directly into the vehicle’s electrical network. Whether this was worth it, however, was debatable.
At the same time, the number of electric vehicles is increasing and leading to new challenges: “The transition to emission-free transport in Europe is facing a critical bottleneck: the electricity grid. If millions of vehicles switch from fossil fuels to electric batteries, the demand for electricity and charging infrastructure will increase enormously,” says the report of the European pilot project “SolarMoves”.
Practical tests over 1.3 million kilometers
The project has now investigated whether photovoltaics integrated into the vehicle (VIPV) could be a solution and whether this solar technology is also worthwhile in Central Europe. “The study analyzed data from 23 different vehicle types – from compact city cars to heavy trucks – and combined detailed vehicle and driving profiles with weather satellite data,” explains project employee Christian Braun from the Fraunhofer Institute for Solar Energy Systems ISE.
The researchers also carried out extensive practical tests in Madrid and Amsterdam. “For this purpose, the vehicles were equipped with sensors and measurement data from 1.3 million kilometers driven were evaluated,” says Braun.
Fewer charging stops and increased range
The analyzes showed: In Central Europe, an electric car can cover up to 35 percent of its annual electricity needs with such solar modules, and in Southern Europe it is even up to 50 percent. This significantly increases their reach. “The number of charging stops required for cars is reduced by up to 56 percent in Central Europe and by up to 76 percent in Southern Europe,” as the researchers report. “In city traffic, an electric car can go for weeks without charging in the summer.”
Delivery vans and trucks can also benefit from vehicle-integrated photovoltaics. Although their overall energy requirements are significantly higher than those of cars, they also have more roof space for the solar cells. The tests showed that such roof solar modules generate up to 55 kilowatt hours of electricity per day in summer. If the side walls of the trucks are also equipped with solar modules, it can even reach 90 to 110 kilowatt hours. This is enough to operate the cooling or hydraulic systems of a diesel truck with completely zero emissions.
Thanks to integrated photovoltaics, electric delivery vans can produce 25 to 30 percent of the electricity they need to drive themselves – and thus increase their range by at least 15 percent. Heavy electric trucks could drive around 50 kilometers further per day than without the solar modules.
Savings in the electricity grid and CO2
The introduction of this technology would have great advantages for the European electricity grid and the transport transition: “If vehicle-integrated photovoltaics and other efficiency-enhancing measures are widely adopted, the EU could reduce its electricity requirements by up to 27 terawatt hours per year by 2030,” says the project report. “This is equivalent to the electricity consumption of a smaller European country.”
These savings would also benefit the climate: “Our study predicts a reduction in CO2 emissions by 2.7 million tons annually by 2030,” report the researchers. If the already registered diesel trucks were also equipped with solar modules, this could save up to 15 to 17 million tons of CO2 per year.
Incentives and bureaucratic adjustments make sense
According to the research team, vehicle-integrated photovoltaics offers clear advantages and could significantly advance the transport transition. “Electrification alone is not enough. We need innovations that structurally reduce energy requirements. VIPV makes a contribution here,” says Lenneke Slooff-Hoek, SolarMoves project manager at TNO.
However, for the technology to become established, more incentives would have to be created at EU level. On the one hand, temporary subsidies or tax breaks for cars and trucks equipped with solar modules could help. Bureaucratic relief and incentives such as the recognition of VIPV electricity as renewable energy and the inclusion of VIPV in the globally harmonized light vehicle test procedure (WLTP) could also be helpful. Companies and fleet operators could then have this credited to their CO2 budget.
Source: Project “SolarMoves”, Final Report 2026 (PDF)