How Expensive Is A Solar-Powered Car?
A solar-powered car is an electric vehicle that is powered primarily or exclusively by energy from the sun. Solar power is converted into electricity using solar panels installed on the car’s surface. This electricity is then either used to directly power the vehicle’s motor or is stored in batteries to extend the car’s driving range.
Solar cars differ greatly from conventional gas-powered vehicles in terms of design, technology, and cost. Building and operating a solar-powered car requires extensive engineering efforts and high-tech components. Factors like the size and efficiency of the solar array, battery capacity, materials, and aerodynamic design all impact the final cost.
In this article, we will analyze the various expenses involved in developing and producing solar-powered cars. What factors make these vehicles so much more expensive than traditional automobiles? By exploring the costs of key components and build processes, we can better understand the current price points of solar cars.
Design and Engineering
Building a solar-powered car requires extensive design and engineering to account for the unique requirements of an electric drivetrain powered by the sun. Some key factors that increase costs include the need for a lightweight chassis, advanced aerodynamics, and maximizing solar panel efficiency.
Lightweighting the chassis using materials like carbon fiber can significantly reduce weight and improve efficiency, but increases costs compared to a traditional steel chassis. The body shape must also be highly aerodynamic to reduce drag at highway speeds, requiring extensive computer modeling and wind tunnel testing during design.
The solar array needs to be carefully engineered to produce enough power from available roof space while keeping weight low. Solar engineers analyze factors like panel efficiency, wiring, and maximum solar irradiation at different times of day. According to research from the Flinn STEM Design Challenge, a solar array for a competition car may cost $5,000-$10,000.
These design requirements mean that engineering costs for a solar car easily reach six figures, far higher than a conventionally powered vehicle.
Solar Panels
Solar-powered cars like the Lightyear 2 use high-efficiency monocrystalline solar panels to maximize energy production from the sun. These panels typically have efficiencies around 20-25%, meaning they can convert that percentage of sunlight into usable electricity [1].
The Lightyear 2 has around 5 square meters of solar panels distributed across the roof and hood of the vehicle. With a solar car like this, you need enough panels to continuously replenish the battery when driving, but not so many that it becomes excessively heavy. 5 square meters provides a good balance [2].
High-efficiency monocrystalline solar panels currently cost around $0.20 to $0.40 per watt. So covering 5 square meters at an average efficiency of 22.5% would cost $2,250 to $4,500 just for the solar panels [2].
Batteries
Solar-powered cars require batteries to store the energy captured by the solar panels. The most common battery types used are lithium-ion batteries, similar to those found in laptops and cell phones. These offer a high energy density, allowing more energy to be stored in a smaller, lighter battery pack (Source).
The battery capacity needs to be large enough to allow the car to drive for extended periods without sunlight. For solar car races like the World Solar Challenge, the minimum battery capacity is typically around 5 kWh. This allows the car to store surplus energy when sunny and continue driving up to 125 miles when overcast (Source).
The battery pack represents one of the biggest costs for a solar car. Prices range from $300-$500 per kWh for lithium-ion batteries. For a 5 kWh pack, the cost would be around $1,500-$2,500. Larger battery packs for extended range can cost $10,000 or more.
Chassis and Body
The chassis and body of a solar car need to be extremely lightweight and aerodynamic to maximize efficiency. Many solar cars use custom-designed carbon fiber or fiberglass composites to reduce weight. According to Freethink, the Aptera solar car uses a lightweight composite body shell that only weighs 100 pounds. The unique shape of the 3-wheeled Aptera body gives it a drag coefficient of just 0.13, making it extremely aerodynamic.
Lightweight materials like carbon fiber and aerodynamic shaping are critical for solar car design. The body must protect components from weather and impacts, while adding minimal weight. Custom lightweight chassis and body components add cost, but dramatically improve efficiency over a traditional automobile shape and materials. Reducing weight and drag is essential to enable a solar car to maximize range from its limited energy source.
Motors and Drivetrain
The motor and drivetrain are critical components that directly impact the power and efficiency of a solar-powered car. Solar cars need powerful yet energy-efficient electric motors to maximize driving range. Popular motors used in solar vehicles include high-torque hub motors or lightweight axial flux motors.
According to SingularityHub, the Aptera solar car uses high-efficiency axial flux motors that deliver a continuous output of around 90 hp. The drivetrain uses a single-speed gear reduction transmission to transfer power efficiently to the wheels.
The motor and drivetrain components alone can cost $5,000 to $10,000 for a small solar car according to industry estimates. Using lightweight materials like aluminum and optimizing the drivetrain design is key to minimizing costs while delivering adequate performance.
Electronics
Solar-powered electric cars like the Aptera and Lightyear 2 require custom electronics designed specifically for efficiency in harnessing and using solar energy. These include maximum power point tracking systems to optimize energy yield from the solar panels as well as lightweight battery management systems to intelligently direct power flows (1). Specialized DC-to-DC converters are also needed to boost the lower voltages from solar panels up to levels required to charge the battery packs, which operate at 200-400V (2).
All of these custom electronics add considerable cost versus a standard electric car. However, by designing them specifically for a solar-powered application, manufacturers can optimize performance and efficiency. Overall electronics systems for solar cars may cost upwards of $5000, but this enables advanced solar harvesting capabilities and extended driving range that would otherwise not be possible (1).
Testing and Development
Designing and developing a solar-powered vehicle requires extensive testing, prototyping, and validation throughout the research and development process. According to Aptera, developing their three-wheeled solar car took over 10 years and cost “multiple tens of millions of dollars”. Building a functional solar car prototype for track testing can cost upwards of $1 million.
Prototyping is an iterative process that allows engineers to test designs, find limitations, and refine the technology. Each design iteration and prototype can cost hundreds of thousands to millions of dollars to manufacture and test on tracks or in road conditions. Extensive wind tunnel, computer modeling, and simulation testing is also conducted to optimize aerodynamics, energy efficiency, and performance.
Competition Costs
Competing in solar car races like the Solar Car Challenge involves significant expenses. Teams must pay registration fees, purchase insurance, transport vehicles and equipment, and cover travel costs for team members. According to the Solar Car Challenge website, the entry fee alone is $3,000 per vehicle.
Teams also incur expenses related to prototyping, testing, repairs, spare parts, and other operating costs over the course of the competition. For example, the University of Michigan team launched a crowdfunding campaign in 2022 with a goal of raising $33,000 to cover costs associated with competing that year after 33 years of racing history (source).
Overall, building and racing a solar car can cost up to $100,000 or more by some estimates. While prices vary based on factors like vehicle design, materials, and team size, competitions involve significant investments for most participants.
Total Costs
All of the advanced engineering and technology that goes into building a solar-powered car makes them far more expensive than conventional cars. According to Energy5, the total cost to design, develop and build a solar car from scratch can range from $500,000 to over $1 million. This is significantly more than even high-end luxury gasoline cars which typically cost around $100,000 to produce.
While the steep initial investment is a major barrier, solar cars have much lower operating expenses compared to gas-powered vehicles. According to Consumer Reports, the typical savings over the life of an electric vehicle ranges from $6,000 to $10,000 compared to a conventional car, mainly from lower fuel and maintenance costs. So over time, solar cars can become more affordable.
As technology improves and solar vehicles move from prototypes to mass production, costs are expected to come down substantially. Sustainable Review predicts that prices will fall by over 50% in the next 5-10 years as manufacturing techniques mature. So in the not-too-distant future, solar cars have the potential to be cost competitive with conventional cars.
