Swedish commercial vehicle manufacturer Scania says it is working on a solar-powered truck, but even the project’s manager admits the need for new hardware and software makes it “a little bit of a wild and crazy idea”.
Part of the company’s larger efforts to electrify transport solutions, the solar-powered truck would generate its own electrical propulsion using solar panels that are installed along the sides of the trailer, which itself is being pulled by a hybrid-electric vehicle.
Development of Scania’s solar-powered truck is being led by Eric Falkgrim, a technology leader at Scania’s Research and Innovation department. Falkgrim leads a small team that are aiming to create the solutions that both build on Scania’s modular system as well as create the necessary new technologies.
A prototype has already been handed over to long-term Scania haulage customer and partner Ernst Express who will test the truck in actual operational conditions on Swedish roads.
However, even though commercial application of the project is some years away, Falkgrim and his team have already seen data that shows promise for the role of solar in the transport sector.
“The data we already have says that solar panels do contribute significantly to the energy you’re getting for the truck, and it’s one part of the overall puzzle when it comes to decarbonised transport,” said Falkgrim.
“The first thing we need to find out is ‘does this make sense?’ And to answer that: yes, it’s good enough to work on the scale that we are doing now.”
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“When we first began thinking about this more than three years ago, our starting point was the lithium-ion batteries that are used in battery-electric trucks,” said Falkgrim.
“In the time that Scania has been working with that technology, we’ve seen the batteries become lighter, cheaper, and more energy dense.
“We asked ourselves: ‘What if solar cells show a similar trend? If the efficiency of the cells doubles, the cost halves or drops away a lot, is there a breakeven point?’ We wanted to find out if it makes sense to develop this technology.”
Development of the project started out in late 2019 with an initial six-month pre-study, before they received funding from the Swedish state innovation agency Vinnova to develop a full-scale project in January 2021. Scania has also received support from Uppsala University who helped with solar cell development.
Falkgrim and his colleagues also used the relatively unlikely conditions of Sweden to their advantage.
“We specifically wanted to see if it made sense in Sweden because if you go to places such as Southern Europe, Australia, or North Africa, there’s obviously a lot more sunshine,” Falkgrim explained.
“If it can work here in the less sunny and somewhat darker conditions then that would confirm the widespread validity of the project.”
Falkgrim’s small team consists of software developers, hardware developers and project management, and has involved no more than a dozen people over the 19-month development process.
“It’s a bit like a start-up,” said Falkgrim. “We knew very early on what we wanted to do. The overall task seems simple – putting solar panels on a truck and plugging it in to the electrical system.
“But it’s a little bit of a wild and crazy idea because it comes with a lot of new hardware and software systemisation and development, to make it safe to handle the transfer of power, and to handle faults.
The plug-in hybrid truck/tractor with all the ‘regular systems’ (100kWh energy storage) is connected to the trailer with additional batteries, which have 200kWh energy storage and act as a ‘power bank’ for the truck, and they’re connected to the solar panel box that charges the power bank.
There were also important safety considerations the team had to work through before letting their prototype out for a spin.
“You have to bear in mind that solar cells are not made to be moving around town in a vehicle,” said Falkgrim.
“They’re designed to sit stationary on top of a house for 20 or 30 years. We’ve had to address safety challenges in putting solar panels on a vehicle.
“So it’s fairly involved from a technical point of view, but we don’t have that pressure of it being a full-scale project where we’re producing something that will be sold globally to hundreds and thousands of customers.
As has been demonstrated in other electromobility sectors, Falkgrim also believes solar-powered trucks could have dramatic implications and benefits for the larger energy industry.
“This could have repercussions for the energy industry. If you scale up the solution you could have thousands of vehicles connected to the grid, so this could have implications for buying and selling electricity to and from the grid.”
“I think there’s a natural development in the industry where energy provision and the transport industry are growing together. There’s a real symbiosis with electrical vehicles. You can produce your own electricity and you can drive on your own electricity, which is a completely new situation.”
Joshua S. Hill is a Melbourne-based journalist who has been writing about climate change, clean technology, and electric vehicles for over 15 years. He has been reporting on electric vehicles and clean technologies for Renew Economy and The Driven since 2012. His preferred mode of transport is his feet.