Can Solar Mitigate Electric Vehicle Charging Challenges?

Australia’s 2023 Bridgestone World Solar Challenge showcased cutting-edge race car innovations that push the envelope of aerodynamic design, power converter performance, and solar-based technologies. These innovations have applications outside the niche of race car design, as engineers can adapt these insights and apply them to the commercial vehicle market as it shifts toward electrified solutions. 

 

ETH Zurich’s aCentauri Solar Racing Team at the starting line. Image used courtesy of Gebruder Weiss

 

A good example is the ETH Zurich aCentauri Solar Racing Team, which implemented Power Integrations' integrated Ccircuit component, the InnoSwitch3, which has many uses outside the scope of racing. Moreover, the team’s success indicates that switching technology can point the way toward the potential power of solar mobility as a solution to electric vehicle (EV) charging challenges.

 

Using a Flyback Switcher With a 750 V GaN Switch

Team aCentauri reached out to Power Integrations to help them design state-of-the-art components for the race car, and one key element is the integrated circuit component known as the InnoSwitch3. This flyback switcher provided a critical boost to system energy efficiency, which could max out at 95.7%. Even when hauling a light load, the car improved overall efficiency by 50%, showing a consistent elevation in performance.

 

 

A diagram of the innoSwitch3. Image used courtesy of Power Integrations

 

This switch technology can be adapted for use in appliances, chargers, adapters, and ultra-low standby power applications, making it a versatile circuit component. 

In addition to Power Integrations’ circuit component contribution to Team aCentauri’s success, the solar components of this race car also suggest the possibility of using solar power to defray the increasing dependence on the utility grid for EV charging. 

 

The EV Market Charging Challenge 

The advancements in the EV market in recent years are undeniable. Engineers are pushing battery technology to new frontiers, and generative AI is improving driving software and other tools that support the EV market. GenAI is even being used to calculate ideal locations for charging stations to help expand charging infrastructure, which must be robust for the millions of EVs about to hit the road.  

Charging infrastructure for EVs has developed in an uneven pattern. Some urban cities have plentiful charging resources, while smaller suburbs and rural areas have limited charging infrastructure. And even in locations with more charging stations, the larger density of EV owners can make accessing those resources difficult. Experts predict longer wait times and congestion in areas that might appear to have more charging resources, but they will be spread too thin.  

 

EVs per charging port organized by state. Image used courtesy of Coast

 

And a dearth of charging stations in certain regions is not the only hurdle that needs to be overcome to facilitate EV adoption. 

Fast-charging capabilities need to be more accessible. Level 1 charging, which describes the common at-home setup that relies on a J1772 connector, is inconvenient. Typically, you will need a full eight-hour charge to support 40 miles of travel.  Forgetting to plug in one night might lead to a missed day of work in the morning for owners with substantial commutes. 

Direct current fast-charging, the most efficient charging option, uses a three-phase AC input to deliver a ratio of over 100 miles per 30 minutes of charging. While direct current fast charging is a significant improvement over level 1 charging, as of 2022, only 20% of public charging stations in the U.S. offered this option.

As a result of charging infrastructure challenges, consumer confidence remains low. 

 

EV consumer reluctance evidence in survey results. Image used courtesy of Statista

 

Solar Power and the EV Charging Gap 

The sun's power might offer critical support for the EV market as it expands. The performance of ETH Zurich’s aCentauri Solar Racing Team this year shows how traveling 3,000 km with only solar power is achievable. The team plans to keep pushing the boundaries of solar mobility, focusing on aerodynamics and efficiency. Their car can already reach speeds of 85 km/h, but with more time and testing, they will likely increase both the speed and performance of their solar race car.

The weight is the most notable difference between an exclusively solar-powered race car and a commercial vehicle. Solar racing cars weigh about 150 kg, while mid-sized commercial vehicles typically weigh between one and two tons. Such a substantial difference might seem to make a solar-powered commercial vehicle impossible. 

 

Combining Solar Power With Lithium-ion Battery Technology  

The answer might be in solar-assisted vehicles that combine the photovoltaic cells used in rooftop solar panels with lithium-ion battery power. 

One of the current complications is a particular design challenge concerning the shape of solar cells. Solar cells are typically made to maximize sunlight capture, and a flat surface is ideal for this utility, but the bodies of cars are sloped. 

Despite the remaining challenges, the positive potential impact of integrating solar power with current EV technology is undeniable. The EV market boom will tax the utility grid in new and unpredictable ways, and supplementing with solar might provide a critical power boost that protects existing grid infrastructure while giving EV charging station infrastructure time to catch up to growing demands.