In response to a federal directive, the Federal Transit Administration (FTA) tasked CALSTART with assessing the viability of wireless charging technology for battery electric buses (BEBs) as an alternative to traditional wired systems. 

As transit agencies face growing pressure to decarbonize fleets, reliable and efficient charging infrastructure is essential. Wireless charging offers the promise of reduced space requirements, streamlined operations, and the ability to extend BEB range through on-route charging. 

However, the technology remains nascent, with standards for high-power systems still under development, limiting widespread deployment and investment, according to CALSTART.

Through comprehensive literature review and stakeholder interviews, the CALSTART report explored the current state of wireless charging — also known as inductive charging — along with its potential advantages, challenges, and implementation barriers within the U.S. transit landscape.

The resulting report highlights practical recommendations to overcome adoption barriers, including the need for standardization, funding strategies, and industry education, while also finding that whether as a primary charging solution or a range extender, high-power wireless charging may play a pivotal role in enabling the transition to zero-emission public transit.

METRO’s Executive Editor Alex Roman spoke to CALSTART’s Brian Ballschmidt, deputy director, technology and demonstration; Brian Lee, lead project manager; and Katrina Sutton, technical project manager about key findings from the report, what the future may hold for wireless charging, and more. 

CALSTART's Inductive Charging Report

METRO: Can you talk about how this report came about — what were the motivations and how did your team get involved?

Sutton: This research was funded by the FTA as part of a larger initiative called the Transit Vehicle Innovation Deployment Centers — TVIDC for short. The goal is to address the challenges around adopting zero-emission buses across the country.

The wireless charging report is one of several projects we're working on. Others include battery fire safety, zero-emission auxiliary heaters, bus specification standardization, and end-of-life applications for zero-emission buses. It’s exciting work, and CALSTART thrives on these innovative efforts.

METRO: I’ve been covering this space for a while. Wireless charging seemed promising early on, but adoption has been slow. What hurdles have kept it from scaling?

Sutton: We interviewed around five or six transit agencies, and responses varied. One of the biggest hurdles is education — many people simply don't know much about wireless charging. That’s why efforts like this report are important. 

It's also about fostering good relationships and communication between transit agencies, OEMs, and wireless charging companies. The technical integration is complex, and those partnerships are critical to success.

Lee: Integrating wireless charging into vehicles requires significant upfront engineering work. Once that’s done, future integrations become easier, but that initial barrier has slowed progress.

Also, wireless charging works best for specific use cases — like fixed-route transit systems where buses can charge during scheduled breaks. For agencies with more dynamic or flexible routes, planning becomes more complicated.

Ballschmidt: I’d add that installing the infrastructure can be a challenge, especially in public spaces where permits and interagency coordination are needed. In contrast, installing chargers at depots is more straightforward because the agency controls the space.

The Impact of Wireless Charging

METRO: From a public transit perspective, how important is wireless charging for extending range and maximizing the benefits of electric buses?

Sutton: It’s interesting — there hasn’t been a ton of organic interest from transit agencies. Many OEMs don’t highlight wireless charging either; they prefer to promote pantograph or wired charging. 

Again, it goes back to awareness and education. That said, I’m really interested in shared-use opportunities — like at airports where shuttles and transit buses could charge at the same station. But that opens up more coordination challenges around rights-of-way and ownership.

Lee: Sharing operational data is essential. Demonstrations — like the one we’re working on with UCLA — help prove the technology’s viability. Plus, on-route wireless charging allows smaller batteries, which lowers costs and reduces capital expenditures. It also lets agencies take advantage of daytime renewable energy sources, especially in places like California with lots of solar power.

Ballschmidt: Another issue is the slow development of standardized requirements. That’s been picking up recently, but it's been a concern. Without standards, agencies are understandably wary — especially around safety and long-term viability.

METRO: How many companies are in the market offering wireless charging right now?

Lee: For high-power transit applications, it really narrows down. We’re mostly looking at systems around 200 to 500 kW. The main players for that range are Electreon Wireless Ltd., WAVE, Induct EV, and possibly a few more.

METRO: You mentioned OEMs being hesitant, why do you feel that is the case?

Sutton: Wireless charging is definitely an add-on — it comes at an extra cost both for OEMs and the transit agencies. Some OEMs have said they don't want to touch it until the market stabilizes. Others are open but cautious, especially because the systems aren’t interoperable.

The lack of standardization is a big concern. Different systems require different tech. SAE J2954 is the standard being developed, with Dash-2 focused on stationary high-power applications like transit. It’s progressing, but we’re not there yet.

Ballschmidt: Plus, there’s a huge backlog for bus manufacturing right now — some OEMs are two-plus years out. That makes them less inclined to invest time or money into new tech like wireless charging unless there’s proven demand and a clear path forward.

METRO: Between pantograph and wireless charging, is one simpler or cheaper?

Lee: Hard to say definitively without full data, but pantographs have had issues with alignment. If the bus isn’t parked just right, the pantograph might not connect properly. There’s also mechanical complexity — if one part fails, the system doesn’t work.

With wireless, the alignment is more forgiving. You just drive over the pad and it charges. Fewer moving parts means fewer mechanical failures.

Ballschmidt: The wireless charging panels are quite large — roughly two to two-and-a-half feet on each side — so there's some room for misalignment.

Overcoming Hurdles is Key

METRO: What’s needed to overcome the current hurdles? Is standardization the key?

Sutton: Yes — standardization is crucial. Without it, it's hard to qualify for funding or ensure long-term viability. 

Hardware costs also matter — wireless usually has a better ratio of chargers to vehicles, but the vehicle-side hardware can be costly. 

Demonstrations and real-world validation are essential too. Agencies want to know: Can it work in snow? Can people safely walk over it? They need that confidence before adopting it.

METRO: Given possible shifts in federal priorities, will reports like this still have impact?

Ballschmidt:CALSTART’s focus on technology and demonstration is about much more than just transit buses. The innovations we explore can ripple out into other vehicle sectors. These efforts support job creation, economic growth, and environmental benefits. Whatever happens politically, I believe we’ll keep pushing forward. This work matters — and it’s not going away.