After decades of promise, solar-powered vehicles are set to contend for auto buyers, as advances in technology overcome their once seemingly insurmountable disadvantages.
By Doug Firby* Special to The Globe and Mail - December, 2020
For three decades, generation after generation of engineering students have been gathering in the University of Waterloo’s Sedra Student Design Centre to create solar cars for international competitions.
Mostly, the resulting vehicles have looked like campy, flat-topped, single-seat Jetsons-style monsters. Yet this 13th complete iteration, labelled the MSXIV, while unconventional looking, is the first in the Midnight Sun Solar Rayce Car Team’s 30-year history that looks like it’s actually made to carry people.
“This will be close to a consumer vehicle,” said Catherine Cai, a computer-engineering student who is Midnight Sun’s project manager.
The MSXIV (pronounced MS fourteen) is a four-passenger sedan being pulled together on a shoestring budget of $200,000 a year, supplemented with manufacturers’ parts donations and thousands of hours of volunteer time, as students aim to demonstrate their engineering chops in international competitions. But unlike earlier versions, the MSXIV looks a lot like something consumers might actually buy.
“Times really have changed,” said Cai, who joined the team in 2018.
The trajectory of the Midnight Sun creations hews closely to what is happening with commercial cars. After decades of promise, solar-powered vehicles are set to contend for auto buyers, as advances in technology overcome their once seemingly insurmountable disadvantages. In fact, two startup car makers in Europe are gearing up to put solar cars into production.
Atlas Technologies, a high-tech firm in Helmond, the Netherlands, operating under the name Lightyear, is taking advance orders on its Lightyear One five-seat sedan and has been testing prototypes since the summer of 2019.
Sono Motors GmbH, based in Roding, Germany, meanwhile, has taken more than 12,000 preorders on its Sion hatchback. The vehicles are to be made in a former SAAB factory in Trollhaettan, Sweden, by NEVS (National Electric Vehicle Sweden), a company that has been making electric cars for Panda New Energy of China.
“This is bigger than it appears at face value for some very big players,” said Peter Harrop, chair of IDTechEx Ltd., a U.K.-based technology-forecasting firm. “They will make an impact that is much bigger than people think.”
A report from IDTechEx released in October said that researchers at the University of York and Nova University in Lisbon have found a way to increase the ability of solar panels to absorb light by 125 per cent. This breakthrough enables thinner, lighter, cheaper and more flexible solar panels, IDTechEx reports, and will make it “certain that most land vehicles will incorporate this technology” in the future, even covering the entire body with solar panels.
“Anyone who doesn’t consider solar [as an option] in their bodywork is an idiot,” Harrop said in an interview.
Major automakers are taking notice. This year, Hyundai offered its Sonata hybrid car to North American buyers with a solar roof option, although Hyundai estimates the panels will add just 3.7 kilometres of range a day on average.
While that may not seem like much, Canadians drive 45 kilometres per day on average, so adding 6 to 7 per cent of a carʼs range is important, says Steve Flamand, director of product and corporate strategy at Hyundai Canada. It could be just enough additional range to keep a car from being stranded on the road.
Hyundai is testing a broad range of prototype electric vehicles – including hybrids, full battery electric vehicles (BEVs), solar-assisted and hydrogen fuel-cell, Flamand said. “We’re pushing the boundaries of electrification every which way.”
Solar-car performance must meet the same criteria as other systems, he said: Is there a tangible benefit? And will consumers think itʼs worth the money? While he said solar is no flavour-of-the-month fad, its prospects hinge on how the technology evolves.
Hyundai is not alone in exploring solar. Toyota began road trials of a solar-fitted Prius hybrid in Japan in 2019. The company said in a news release that the ultrathin solar panels, made by Sharp, have reached “a conversion efficiency of 34 per cent-plus” and are capable of delivering 860 watts of power. Tesla, whose chief executive officer Elon Musk once dismissed solar, has also added a solar-roof option on the Cybertruck prototype.
Solar-powered vehicles, which are essentially battery electric vehicles fitted with solar panels, offer several advantages over BEVs alone. They reduce range anxiety, cut the plug-in time required to recharge batteries and will eventually be “energy independent” – needing no plug-in time at all, Harrop says.
The Lightyear One five-seater is handsome enough that owners need no longer fear being labelled nerds. Priced at €119,000 ($183,000), the car has two to three times the energy efficiency of BEVs on the market, Lightyear says, thanks in part to a drag coefficient (Cd) of less than 0.2. (Modern cars typically have Cds of 0.25 to 0.3; SUVs are typically rated between 0.35 and 0.45.) It has five square metres of curved solar panels, four independently controlled in-wheel motors and a 97-per-cent efficient drivetrain.
Range is rated at 725 kilometres on a full charge, and the company asserts it could provide up to 20,000 kilometres a year of solar range. Production is to start in 2021.
But the forecast is not entirely sunny for solar cars. Among their downsides are the high price of solar panels, the massive surface area required to accommodate them and the question of what happens on cloudy days.
Sono is tackling these drawbacks head-on in its Sion production vehicle, which is to begin deliveries in early 2022. Engineers have designed polymer body panels that integrate solar cells over the entire surface of the vehicle. (Polymer is both lighter and cheaper than glass, as Lightyear is using.) That limits the colour choices to one – black – but Sono claims the panels are 20 per cent lighter than metal body parts.
The car has an estimated range of 255 kilometres a day from a full charge (including 34 kilometres a day on solar alone). It is rated at the equivalent of 163 horsepower, can hold five passengers, has a trunk volume of 650 litres and will even come with a towing bar rated at 750 kilograms in Europe. Most remarkable, though, is the price: expected to be €25,500 (about $39,550).
Despite the optimism, skeptics are not hard to find.
Jeremy Michalek, a professor of mechanical engineering at Carnegie Mellon University in Pittsburgh and director of its Vehicle Electrification Group, notes that solar charging requires ideal conditions – that the vehicle’s solar panels be clean, the car well-positioned to capture the sun and the stored energy enough to keep the car moving when the sun sets.
Parking a car in a suburban garage on snowy days or in an underground parking facility will also limit opportunities for solar charging.
While it might be possible to charge an EV battery with on-board solar panels, he said, using solar power captured from panels on a building’s roof actually makes more sense because it eases space limitations and places fewer restrictions on the vehicle’s parking location.
Still, Harrop’s IDTechEx predicts that the argument in favour of solar-powered vehicles is “so clear and compelling” it is certain most land vehicles will incorporate this technology as an essential part of their battery electric powertrains.
“In a sense, it’s a done deal,” said Harrop, “that ships, aircraft and automobiles will have solar-assist at least.”
Cai, of Midnight Sun, agrees. Consumer-friendly solar cars will be common “within our lifetime,” she predicts. Since she’s in her 20s, it could be decades away.
About the Author
*Doug Firby is an Associate Director, Communications, Media and Marketing at Sunshine Village Ski and Snowboard Resort
UNIVERSITY OF WATERLOO/HANDOUT - About the photo: University of Waterloo engineering students show off the with MS XII solar car at the Circuit of Americas in Austin, Texas, in 2019.