The principles of design necessary to make solar electric vehicles viable offer valuable insight on the overall importance of efficiency. By Will Girling
The battery electric vehicle (BEV) market has generally sought to imitate the internal combustion engine (ICE) models that have driven on the world’s roads for years. While this process started out relatively small—hatchbacks (such as the Nissan Leaf) and mid-size sedans (Tesla Model 3)—it has now progressed to SUVs (Hyundai Ioniq 5) and pick-ups (Ford F-150 Lightning). On average, BEVs are becoming larger: in 2022, 55% of the electric models available on the global market were SUVs, according to the International Energy Agency.
Significantly, these models have a capacious footprint for housing more batteries and therefore achieving greater range. Despite some advantages, however, bigger batteries are a strain on supply chains and more expensive to produce and purchase. In addition, they are often inefficient, as increasing the weight of an already large vehicle consequently requires more energy to move it in the first place.
Chris Anthony, Co-Chief Executive of Aptera, believes BEV manufacturers could learn valuable principles in overall design efficiency from the solar EV (SEV) segment. “The bigger and heavier your vehicle, the more energy it uses,” he tells Automotive World. “When Aptera was started, we had to answer one question: how can we use the least energy per mile possible? Breaking it down, the science told us the answer is aerodynamics and rolling resistance.”
Mass producible, highly aerodynamic
Aptera’s first challenge was to manufacture a highly aerodynamic vehicle that was still mass producible. Seeking advice from Sandy Munro, a known automotive industry engineer and consultant, the company settled on a six-piece body structure made from carbon fibre sheet moulding compound (CF-SMC). The structure of this material is strong and light but easily press-moulded, properties which have won it some limited uptake in the construction of vehicles from Lamborghini, BMW, and Toyota.
Combining CF-SMC with glass-fibre SMC throughout the entire body means Aptera doesn’t need to use welding and robotics during manufacturing: its SEV can be assembled purely through bonding the six components together. The company also used generative artificial intelligence-driven tools to help reduce the vehicle’s weight throughout the design. “The heaviest part—the ‘tub’—is about 50lbs (23kg), and the entire body structure weighs less than an average person,” states Anthony.
When factoring in all other necessary components, Aptera’s production vehicle weighs about 1,000kg—37-42% lighter than a Nissan Leaf and 63% less than a F-150 Lightning—and has a top speed of 110mph. Although a common criticism of SEVs is their prohibitively expensive sticker price—Dutch start-up Lightyear’s 0 model cost US$281,000, for example—Aptera’s eponymous two-seater is estimated to start at US$25,900, significantly cheaper than most BEVs. Production for the Launch Edition model is scheduled for Q3 2025, and the company will offer four lithium-ion battery sizes with four corresponding range specs: 25kWh for 250 miles, 42kWh/400 miles, 60kWh/600 miles, and 100kWh/1,000 miles.
Efficient powertrain
Notably, the Aptera SEV’s performance compares favourably with leaders in the BEV space: the Tesla Model Y Standard’s 60kWh battery, for example, can achieve only around 300 miles from a full charge. So, how does the company’s powertrain extract double the performance from the same sized battery? The answer, says Anthony, is what makes incorporating solar power possible in the first place: efficiency.
Aptera incorporates monocrystalline, interdigited back contact (IBC) cells on its cars by removing and replacing the roof panels, dash, hood, and hatch. These flexible units can be moulded to the vehicle’s shape to retain aerodynamics while still meeting automotive-grade shake, vibration, and temperature requirements. Each SEV’s three-square-meter, 700W solar array weighs only eight pounds. In a sunny climate like Aptera’s native California, this technology enables an Aptera SEV to charge up to 40 miles per day from the sun alone. “Depending on the state, that could be 8,000-11,000 miles of free driving a year,” says Anthony.
Attaining that level of performance means Aptera’s power conversion system must remain optimised at all times—if it suddenly drives into a shaded area, the vehicle needs to continue operating at peak efficiency. Anthony states this is achieved through Aptera’s Maximum PowerPoint Tracking algorithm: “Our solar charge controller sends power from a high-voltage battery pack to the wheels super efficiently. This is technology that hasn’t really existed in the automotive space before, and we’re also exploring opportunities to monetise it in other industries.”
By combining a highly efficient powertrain with a lightweight body, Aptera estimates that its SEVs can achieve 350 miles per gallon equivalent from a battery one-quarter the size of a typical cell. “Using this system, they can subsequently also charge five times faster than standard BEVs,” Anthony adds, “and our charging network is wherever the sun is shining.”
A culture shift
While SEVs might hold a lot of promise, they are likely to remain a niche segment in the medium term—by 2034, the global market is forecast to reach a value of just US$1.5bn, according to Precedence Research. Furthermore, applying solar technology to the BEV segment could be difficult and expensive depending on an automaker’s initial vehicle platform. Success would be proportional to the vehicle’s surface area and the degree of efficiency sought during product R&D.
By making the essentials cheaper, you can spend the savings on new materials and lightweight parts and still offer an affordable alternative to ICE
Regardless of whether SEVs gain an appreciable market share relative to BEVs, Anthony believes the core technology and design philosophy can still play a role in solving consumer adoption hesitancy, burgeoning infrastructure issues, and high production expenses. While a peripheral player like Lucid has made efficiency a core pillar of its brand, other manufacturers aren’t quite as committed. “Some OEMs are working more on this than others. There’s a place for solar in general automotive, but the industry first needs a cultural shift away from big SUVs and pick-ups.”
Crucially, this shift would need to encompass not only products but also the processes through which they are created. “The economics of manufacturing most BEVs isn’t very attractive,” says Anthony. “Some automakers are losing tens of thousands of dollars per vehicle through inefficient manufacturing processes.” In contrast, he notes that Aptera integrates efficiency and profitability throughout its vehicle—from the small battery to a body material that can be coloured using vinyl wrap instead of paint, mitigating the need to amortise the high capex of paint facilities. “By making the essentials cheaper, you can spend the savings on new materials and lightweight parts and still offer an affordable alternative to ICE,” he concludes.
