Scania is testing a hybrid truck with a solar-panel-covered trailer that uses the sun’s energy to help propel the vehicle during trials on public roads in Sweden

The research project looks to determine how much emissions can be reduced using the lightweight solar panels. Researchers are also looking at how the truck can interact with the power grid, potentially selling surplus solar power.

“Scania’s purpose is to drive the shift towards a sustainable transport system. Never before have solar panels been used to generate energy to a truck’s powertrain like we do in this collaboration. This natural energy source can significantly decrease emissions in the transport sector. It is great to be at the forefront in the development of the next generation’s trucks,” Stas Krupenia, head of the research office at Scania, said in a release.

The 18-meter trailer is almost completely covered in solar panels, which could provide 5,000 km of annual driving range in Sweden, and more in countries with more sunlight. New solar cells in development could double the solar energy generation, the company says.

“Our solar panels are excellent for applications that make commercial vehicles sustainable,” said Erik Olsson, head of corporate development with Midsummer, which produces the panels. “We see great potential to decrease the emissions from heavy vehicles with electrification. Electricity generated by solar panels will save fuel and carbon emissions. We want to be a partner to count on, and that is enabled by this groundbreaking project.”

The Scania truck is a 560-hp plug-in hybrid. The trailer contains more than 100 square meters of solar panels. The truck has 100 kWh of battery capacity, with another 200 kWh on the trailer.