Integrated solar panels could help electric cars compete with their fossil-fuel counterparts by making them less dependent on charging points and able to run for free, says leading solar Lightyear engineer Emanuele Cornagliotti in this interview as part of our Solar Revolution series.

“I think most electric vehicles will have a solar roof in the future,” he told Dezeen. “This is a topic that all the major car manufacturers are working on.”

A solar powered car driving in the desert
Lightyear has developed a production-ready solar car (above and beyond)

Dutch startup Lightyear has just launched what it calls “the world’s first production-ready solar car”, the Lightyear 0, which needs to be charged like a regular electric vehicle (EV) but automatically will be filled with a five square meter solar array. covering its roof, hood and tailgate.

That means the average driver in a sunny country like Spain can use the car for up to seven months without having to plug it in, Lightyear said.

Vehicles can “basically run for free” on solar

Solar-assisted cars like this will be “normal within 20 years”, according to Cornagliotti, once mass production is scaled up and prices come down.

This time, he says that their size could increase by 50 percent if the next generation of ultra-efficient tandem solar cells, which use a layer of perovskite to better absorb sunlight, fulfill their promise.

Lightyear 0 is parked in the sun
Photovoltaics cover its roof, hood and tailgate

This will help to solve the major challenges around the fact that charging infrastructure and grid capacity have so far failed to keep up with the development of electric vehicles, Cornagliotti admitted.

“If we have a major leap in solar-cell efficiency, then I think vehicle-integrated photovoltaics will really be a no-brainer,” he said.

“You have to pay less, you have to charge less and you’re helping the energy transition because you’re not overloading the grid,” he continued. “You always need a plug. But if you don’t use your car, it’s free to use.”

Solar can help close the EV efficiency gap

Lightyear is one of several startups racing to get solar-powered electric cars to people, including US company Aptera Motors and Munich-based Sono Motors.

But even more household names are betting on vehicle-integrated photovoltaics (VIPV), with Hyundai incorporating a solar roof into the Sonata hybrid, Mercedes-Benz creating a photovoltaic bonnet for the Project Maybach concept car and Tesla is reportedly set to offer an optional solar- add to the Cybertruck.

Three wheeler solar car by Aptera
Another company developing solar cars is US-based Aptera

The hope is that this new technology will help close the efficiency gap between cars that run on gasoline and those that run on electricity. Because currently, driving an EV with a battery capacity of 60 kilowatt-hours is basically equivalent to driving six liters of gasoline, Cornagliotti said.

“That’s a very small amount of energy,” he explained. “For this basic reason, an electric car should naturally be more efficient than an internal combustion engine car.

Double-curved solar panels are “key innovations”

The challenge with VIPVs is to integrate them into the vehicle in the most efficient way possible, to maximize the amount of sunlight that can be captured without adding weight or bulk that slows the vehicle down.

For the Lightyear 0, Cornagliotti and his team sought to achieve this by developing double-curved solar panels, which do not sit on top of the vehicle but effectively replace its regular steel body parts. This preserves the aerodynamic shape of the car while increasing the solar area.

Project Maybach concept car by Mercedes-Benz and Virgil Abloh
Mercedes-Benz’s solar concept car has a transparent bonnet

“Traditionally, solar panels are flat and made with a fairly straightforward flat-lamination process,” he explained. “But when you build a flat solar roof, you restrict the area and aerodynamically it doesn’t work well.”

“So developing the manufacturing process for curved panels is one of the key innovations here.”

Not much has been shared about this trade secret process, other than the fact that it involves hard silicon solar cells cut into small pieces, carefully laminated to a curved backsheet so as not to break the photovoltaics , and put forward a glass front.

Cost poses a barrier for accessibility

Photovoltaics integrated into cars are symbols of a new phase of solar technology that Dezeen is exploring as part of the Solar Revolution series, which focuses on getting photovoltaics from remote fields and i -embedding it in our products and buildings so they can meet their own energy needs. .

“We need to have more solar power everywhere as quickly as possible,” Cornagliotti said. “So it’s not about choosing where we put solar panels, but it’s about putting them wherever we can.”

“You want your solar production to be as close to the point of use as possible because that means you don’t need to use the grid and you prevent the loss of energy that occurs at every step of the transmission process.”

Currently, the Lightyear 0 has a hefty price tag of €250,000. But in 2025, the company hopes to make a more widely affordable and accessible model called Lightyear 2, which it aims to sell for only €30,000 despite the fact that the costs for raw materials such as of polysilicon for solar cells and lithium for EV batteries currently. to climb.

To achieve this huge price cut, Lightyear had to adapt and scale up the semi-manual lamination process used to make its curved solar panels for mass production.

It also needs to find cheaper alternatives for the structural support materials used in its panels, which are expensive but necessary to ensure the safety of drivers and pedestrians.

“We see Lightyear 0 as more of a technology demonstrator in the sense that the cost is relatively high,” explained Cornagliotti. “But we don’t see a fundamental reason why the price can’t measure up to a level that consumers can accept.”

The solar roof of the Lightyear 0 solar car
The solar array of Lightyear 0 covers five square meters

“In 10 years, having a solar body will be slightly more expensive than using iron,” he added. “And solar-panel cars will be the norm within 20 years.”

Although Cornagliotti believes that this rapid progress can be made by 2042, it may not be enough to limit global warming to the important threshold of 1.5 degrees Celsius outlined in the Paris Agreement.

To hit this target and prevent catastrophic and irreversible climate change, all sales of new fossil-fuel cars must stop nearly a decade earlier by 2035, according to International Energy Agency data.

The embodied carbon in solar panels must be cut

Solar body parts also have a higher carbon footprint than their steel counterparts thanks to the materials that must be mined and refined to make the photovoltaics and their electronics.

Electric cars already generate 30 to 40 percent more emissions in their production than fossil-fuel cars, with estimates suggesting it will take six months and five years for them to catch up. offset the carbon footprint of their lithium-ion batteries through operational savings. emissions.

The back of Lightyear 0
It extends beyond the roof to cover the tailgate

Adding solar panels to the Lightyear 0 adds an additional five to ten years to this equation, depending on the location where it is charged. But Cornagliotti and his team are now working on cutting that down to two years.

“In the future, you will have everything connected so that the conversion system, the solar system and the high voltage battery are packaged,” he said. “The cost of carbon keeps getting lower.”

A number of car manufacturers are now working to eliminate the included carbon footprint of electric vehicles. Swedish company Polestar hopes to develop the “world’s first climate-neutral car” by 2030, while BMW recently unveiled a circular concept car designed to be easily dismantled at the end of its life. .


Solar Revolution logo
Description by Berke Yazicioglu

Solar Revolution

This article is part of Dezeen’s Solar Revolution series, which explores the diverse and exciting potential uses of solar energy and how humans can make the most of the sun’s incredible power.