Lightyear announced in January that it had hit another milestone with the testing of its first car, the upcoming solar electric Lightyear One. The company said that the results of recent efficiency testing in Aprilia, Italy, bring it closer to its ultimate goal of getting the world’s most efficient and sustainable cars to market.

The Aprilia testing, which focused on aerodynamics, tire performance, and efficiency at higher speeds, took place at Bridgestone‘s European Proving Ground (EUPG). Key specs evaluated included battery capacity, speed, energy consumption, and range—all part of the equation for the company’s goal of optimal vehicle efficiency.

Testing speed was brought up to 130 km/h (81 mph), from 85 km/h (53 mph) in prior testing, and took place in much cooler weather conditions of around 10°C (50°F). Engineers reported an energy consumption as low as 141 W·h/km, which the company says makes the Lightyear One the most efficient car of those currently on the market. The results confirm that it is on its way to producing the most efficient car ever, not just in legislative cycles, but also in real-world conditions.

‍”If we compare with other vehicles right now, Lightyear One can drive one and a half times further than a directly comparable vehicle with the same battery size,” confirmed Megan Parfitt, Vehicle Test Coordinator.

Despite the suboptimal conditions, the tests showed that a charge of the car’s relatively small 60-kW·h battery, and running at 130 km/h, results in a range of over 400 km (249 mi)—a journey equivalent of Amsterdam to Luxembourg at highway speeds—no matter the weather. The company says that a comparable EV can go 265 km (167 mi).

During the partly cloudy test day, the Lightyear One added 26 mi (42 km) of range from the solar panel directly. On a sunny day, that number would grow.

The Aprilia testing follows June 2021 results from Aldenhoven, Germany, of the validation prototype. The test crew saw over 440 mi (710 km) from the 60-kW·h battery at a speed of 85 km/h, driving for almost 9 h straight on a single charge.

 

Most aerodynamic five-seater

According to the company, the car’s energy consumption, and therefore efficiency, depends on three key elements: the heating system, rolling resistance, and aerodynamics. Aerodynamics is a major energy consumer, especially at higher speeds, directly impacting highway range.

For the Lightyear One, engineers had to strike a careful balance between aerodynamic performance and sleek looks, solar panel integration, the large (780 L) storage space, and a user-friendly experience. They look at the review of real-life performance as a critical step toward achieving that balance.

“What we are trying to acquire here is information about how the car behaves in a natural environment,” explained Federico Garcia, Aerodynamic Engineer, of the Aprilia testing.

Tests consisted of driving at varying speeds, taking wake measurements of air pressure around the car, and monitoring power consumption.

“For the measurements around the car, we use specially made rakes,” said Annemiek Koers, an aerodynamic engineer on the team, of the Aprilia testing.

The rakes, or grid structures fitted with sensors, were placed at different positions on the car.

“Those sensors are connected to a data acquisition system,” explained Koers. “We measure the pressure at different locations around the car with that system.”

Results of the road tests confirmed that Lightyear is on track to produce the most aerodynamic five-seater to date, with a record-breaking drag coefficient (Cd) of less than 0.20. The current EV leaders in this segment are the Mercedes-Benz EQS and Tesla Model S at or just above that mark.

 

Founded by world champions

Lightyear was founded with the mission to provide clean mobility for everyone everywhere.

“We started thinking about this concept back in 2012 [when] we competed in the World Solar Challenge,” said Lightyear CEO Lex Hoefsloot on a YouTube video keynote presentation in December.

That competition traverses 3000 km (1860 mi) in Australia from Darwin to Adelaide in solar-powered vehicles designed, engineered, and built by student teams. The team that evolved into the Lightyear company won the competition four times in a row, and with that experience and know-how decided to engineer a production solar electric car.

The company did not want to depend on the uptake of charging infrastructure “because that might delay things,” according to Hoefsloot, and it wanted to provide people with an electric car they can start driving tomorrow so they don’t have to change their habits. For the past five years, it has developed that car, which can drive independently from the grid, by making it ultra-efficient so it uses less energy and by building solar arrays that have more energy yield.

Company engineers reduced energy consumption by not only improving aerodynamic performance but also by reducing the weight and rolling friction of the car and improving its powertrain efficiency.

He attributes much of the efficiency gains to in-wheel motors that don’t need any gears, reducing heat loss.

“Because the powertrain is more efficient then, in turn, the battery can be smaller,” elaborated Hoefsloot. “And if the battery is smaller, then the whole car is lighter. Also, if the battery is smaller, you can improve the aerodynamic performance. So, all these factors are interlinked. If you start with a blank piece of paper, you can really leverage this effect and build something that is incredibly efficient.”

The other significant part of the Lightyear story is the further reduction in energy needed from the grid by adding solar panels.

“We did that by building solar arrays that you can…curve in all directions, so that means that you can build a much bigger panel on top of an electric car,” he said. “We also developed electronics that make sure you can get the most out of the solar panel at every moment—even when you’re partly in the shade. This gets us to, on average, five times less charging.”

Hoefsloot is excited that “all of these factors will keep improving into the future. We already see what we can do beyond the Lightyear One.”

He sees the car becoming energy positive, providing more energy than it needs.

“That’s the case currently already with Lightyear One in some countries like Italy and Japan,” he said. “In the future, a lot more countries will have cars that are energy positive.”

 

Reducing the burden on electric infrastructure

During the YouTube keynote, Hoefsloot discussed his company’s strategic roadmap and product vision in context with the bigger picture.

“Clearly, we need 100% clean cars, and there’s about 1 billion of them,” he said of the current car PARC or population. “And there’s another 1 billion coming in the next 20 years, and all of those cars need to be clean as well. It’s not just the early adopters we need; we need literally everyone to drive an electric car.”

To scale for the needed two billion EVs, he believes they need to be compatible with the lifestyles of people and the product should have a very clear distinctive advantage compared to the other products on the market.

“To make electric cars convenient, you need about one charger per car,” he said. “We have about seven million chargers, and of course, we’ll need about one billion to make it convenient.”

Where will the world’s EV drivers get the energy?

“The energy that you might get from the solar panels of your house, you actually need for your house,” he said. “The energy has to come from somewhere else.”

He added that if the two billion cars are converted to electricity the global electrical grid will be challenged.

“There’s going to be five times more demand during the evening peak,” he said. “The grid currently cannot cope with that, so it means that we will need to reinforce the grid as well.”

He says that the energy going into the grid is still mostly from coal and gas powerplants, and that needs to be addressed.

“All of this change will have to come in every country, so how realistic is it that we’ll get there as soon as possible?” he asked.

“With all this uncertainty, there’s one constant, and it’s the sun,” he said. “We can use it every day to charge our cars because in the end, people don’t really want chargers, they want a full battery. Why don’t we use the sun directly to charge our batteries every day?”

That direct solar charging can reduce the huge charging-network investment that will be needed in the coming few years.

“If we just look at Europe, we need about €80 billion to deploy all those chargers to get to scale,” he said. “If we would make the transition to solar mobility, then we can actually reduce that number by a factor of three because we need three times fewer chargers. Extrapolated to the rest of the world, it means we can save humanity more than €100 billion on investing in this infrastructure.”

 

Backed by strong partners

Hoefsloot acknowledges that Lightyear cannot create all of the innovation alone and is relying on strong partners in key areas.

One of those partners is Valmet Automotive. Lightyear is tapping into that company’s manufacturing expertise to produce the car so Lightyear can focus on the technology.

“Valmet Automotive is building its strategy fully on the transformation from combustion engines to electric vehicles,” said Olaf Bongwald, CEO, of Valmet Automotive. “Lightyear is thinking ahead. They are thinking…about building a car that is energy efficient. The next step must be, how can we drive as energy efficient as possible if we want to support the climate targets.”

Another partner is Bridgestone. Lightyear says that the tire is not only an important element for safety and comfort, but it also enables efficiency for long range.

“Their engineers together with our engineers have developed a tire that has the lowest rolling resistance of any tire they have ever developed,” said Hoefsloot. “And that makes a Lightyear One even more efficient.”

During the Aprilia testing, vehicle engineers wanted to confirm how the chosen Bridgestone Turanza Eco tires would perform. The combination of Enliten and Ologic technologies is intended to reduce aerodynamic drag and rolling resistance while also being lightweight.

Tests were conducted by a Bridgestone and a Lightyear driver on three tires from the high-tech family. The reference (baseline), comfort-oriented, and handling-oriented tires were evaluated for comfort, rolling noise, straight running and steering behavior, and lane changes. The tire with a more handling and steering focus was selected by Lightyear engineers, as it offered more control and was stronger overall.

“When it comes to a good tire, it’s all about balance,” said Koen Broeksteeg, Lead Engineer Vehicle Dynamics, Lightyear. “For our tires, what we gain in handling and steering performance far outweighs what we would obtain from going with a more comfortable tire.”

Lightyear also announced a long-term partnership last year with NXP for technology applied to its cars’ battery management system, driver-vehicle interface, vehicle control unit, and solar converters—and to accelerate the development of vehicle autonomy.

The NXP partnership “enables rapid prototyping,” said Hoefsloot. “This accelerates our time-to-market significantly. With this partnership, we will also focus on inserting autonomous driving in our next mass-market model.”

 

On the road to more affordable solar cars

The first Lightyear Ones will be delivered to customers this year, but that is just the first step in the company’s mission to provide clean mobility for everyone, according to the CEO.

“We’re the first to admit that the Lightyear One, our first vehicle, is not an affordable car, so it’s not yet for everyone,” said Hoefsloot. “The Lightyear One can show that you can go everywhere with just the sun and normal power sockets, but the next step is really [to] get to mass markets and build affordable cars for everyone.”

While acknowledging that the challenge of acceptable range has been addressed for some EVs, he says that solving the range, charging, and cost challenges at the same time is exponentially harder. To do that, the company intends to bring Lightyear One’s technology to mass markets, adding low cost to the equation with the company’s second car—the Lightyear Two.

“Like Lightyear One, Lightyear Two will hit a home run on those key factors of charging and range, and it will improve not just by a bit but really by a large margin,” he said.

He said it will require about five times less charging and has about double the range to conventional EVs.

“And when you do need to recharge, the recharge will be quick from the normal socket you have at home or in a neighborhood, because a smaller battery will be charged a lot faster than a big battery,” he added.

Producing at scale with small batteries enables the affordable Lightyear car, which will start at a €30k price point.

The low cost will be more than just about purchase price, added Hoefsloot.

“It’s also about how much it costs to drive the car because you get all the energy from a solar panel for free,” he said. “It’s a lot more affordable to drive it. So, in the end, these types of cars are going to be a lot more affordable than combustion cars are today.”

Still greater affordability will be provided by leasing.

“To give people the possibility to benefit from that very low total cost of ownership, we’re going to provide a leasing option on Lightyear Two,” said Hoefsloot. “LeasePlan has committed to an initial order of 5000 Lightyear Twos.”

Lightyear recently announced it is expanding the partnership it struck in 2018 for the Lightyear One with LeasePlan, one of the biggest leasing companies globally with a fleet of about 1.8 million cars in 29 countries, for the Lightyear Two.

“This is not just a strong signal that LeasePlan is committed to making clean mobility happen,” said Hoefsloot. “It also shows their confidence in the market for grid-independent vehicles. I want to thank LeasePlan CEO Tex Gunning and his team for his commitment, the partnership, and the leadership that they’re showing.”

Lightyear’s roadmap is getting more focused on the ultimate company mission.

With Lightyear One, “we’re going to show that you can actually drive on the sun with a technology that exists today,” he said. “With Lightyear Two, we’re going to bring that technology to mass markets and really get very close to that ‘clean mobility for everyone’ mission that we have as a company.”

 

More on Lightyear

Lightyear’s prototype drives over 440 mi with 60-kW·h battery

Bridgestone aids Lightyear solar car efficiency with custom tires

Lightyear leads solar-car charge with the One