WEST LAFAYETTE, Ind. — Indiana, often hailed as the “Crossroads of America,” is becoming a hub of innovation for electric vehicle (EV) technology. Purdue University engineers and the Indiana Department of Transportation (INDOT) are collaborating to pioneer dynamic wireless power transfer, enabling EVs, from large semi-trucks to passenger cars, to charge wirelessly while driving on highways – a key component of a forward-thinking “Indot Cars Program”.
Currently under construction in West Lafayette is a quarter-mile test bed on U.S. Highway 231/U.S. Highway 52. This site will be crucial for evaluating a patent-pending system developed by Purdue engineers. The aim is to efficiently deliver power to heavy-duty electric trucks traveling at highway speeds, marking a significant step in the “indot cars program”.
Indiana Governor Eric Holcomb highlighted the project’s groundbreaking nature at COP27, a United Nations environmental conference, stating, “Thanks once again to some engineers and pioneers from Purdue, we’re developing the world’s first highway test bed for wireless charging. Yes, we will be testing whether concrete can charge passing trucks — and don’t bet against a Purdue Boilermaker.” This initiative underscores Indiana’s commitment to green energy and positions the “indot cars program” at the forefront of sustainable transportation solutions.
Construction of this innovative test bed, integral to the “indot cars program”, commenced on April 1 and is projected to continue through the fall. A heavy-duty electric truck from Cummins Inc., an Indiana-based company, will be utilized to test the wireless charging system as part of a pilot program slated for next year. The ambitious long-term goal of the “indot cars program” is to electrify a section of an Indiana interstate within the next four to five years, transforming highway infrastructure for electric vehicles.
Advancing Wireless EV Charging for Highways: A National Challenge
While other regions globally are exploring wireless EV charging roads, the “indot cars program” and Purdue initiative uniquely tackle the challenges of highway-speed charging, especially for heavy-duty trucks. Higher speeds demand significantly greater power levels for effective wireless charging compared to urban road conditions.
The wireless charging system designed by Purdue is engineered to operate at power levels exceeding current U.S. demonstrations. By meeting the high-power requirements of heavy-duty vehicles, the “indot cars program”’s infrastructure will also readily support the lower power needs of lighter vehicle classes, ensuring broad applicability.
Prioritizing Heavy-Duty Trucks: Maximizing Impact of Electrified Highways
Electrifying Indiana’s highways, a core objective of the “indot cars program”, holds national significance due to the state’s central location. Eighty percent of the U.S. population is within a day’s drive of Indiana’s extensive highway network.
Focusing on heavy-duty trucks first in the “indot cars program” maximizes the environmental and economic benefits of electrified highways. Heavy-duty trucks are major contributors to greenhouse gas emissions within the U.S. transportation sector. Their high fuel consumption and crucial role in freight transport make them a prime target for electrification.
Nadia Gkritza, a Purdue professor in civil engineering and agricultural and biological engineering, explains, “The so-called ‘middle mile’ of the supply chain… is the most challenging part of the transportation sector to decarbonize.” The “indot cars program” directly addresses this challenge by focusing on electrifying freight routes.
By enabling electric heavy-duty trucks to charge dynamically via highways under the “indot cars program”, battery size can be reduced, cargo capacity increased, and operational costs lowered. Given trucking’s substantial contribution to the U.S. GDP, the “indot cars program”’s cost reductions for electric heavy-duty trucks can stimulate investment in nationwide electrified highway infrastructure, benefiting all EV classes.
Professor John Haddock from Purdue’s Lyles School of Civil Engineering, emphasizes the system’s power, stating it’s designed to “charge semitractor-trailers as they move 65 miles per hour down the road.” This capability is central to the “indot cars program”’s vision.
Wireless EV Charging: Highways Functioning Like Smartphone Charging Pads
The “indot cars program” leverages technology enabling highway pavement to wirelessly power EVs, analogous to smartphone wireless charging pads. This inductive charging method uses magnetic fields to transfer energy.
Purdue’s Edmund O. Schweitzer, III Professor of Electrical and Computer Engineering, Steve Pekarek, explains, “If you have a cellphone and you place it on a charger…magnetic fields…[transfer energy]. We’re doing something similar…only…power levels are higher and you’re going out across a large distance from the roadway to the vehicle.” This system, a cornerstone of the “indot cars program”, offers a streamlined charging solution, with complex aspects managed by vehicle manufacturers.
The wireless charging system within the “indot cars program” involves transmitter coils embedded beneath concrete in dedicated highway lanes. These coils transmit power to receiver coils attached to the underside of EVs. The Purdue design innovatively accommodates the high power demands of heavy-duty trucks with a single receiver coil assembly under the tractor, simplifying the system compared to multi-coil approaches.
Furthermore, Purdue’s transmitter coils are designed for concrete pavement, which constitutes 20% of the U.S. interstate system. This is a significant advancement as other designs are primarily for asphalt. Research Assistant Professor Aaron Brovont notes the potential of the “indot cars program” for cost savings: “If you can charge your car on the road while in motion, then you’re basically riding for free.”
Pavement testing under the “indot cars program” includes rigorous mechanical load assessments on 20-foot concrete and asphalt sections with embedded transmitter coils. Machines simulate heavy truck traffic to evaluate durability. Simultaneously, lab tests validate the electromagnetic performance of transmitter and receiver coils, ensuring the system’s effectiveness.
Paving the Way for Nationwide Electrified Highways through the “Indot Cars Program”
The “indot cars program” and Purdue’s research are gaining national attention, featured in outlets like The New York Times and CNBC, highlighting its potential to shape EV charging infrastructure.
Partnerships extend beyond Indiana. Funded by INDOT via the Joint Transportation Research Program and affiliated with ASPIRE, a National Science Foundation Engineering Research Center, the “indot cars program” is part of a broader national effort. Purdue is a founding member of ASPIRE, with Professor Gkritza as campus director.
ASPIRE, headquartered at Utah State University, unites over 400 members across 10 universities and 60 industry, government, and non-profit partners, advancing electrified transportation. Purdue and Cummins, key ASPIRE members, are also collaborating on a U.S. Department of Energy-funded project to develop an EV charging and hydrogen fueling plan for medium- and heavy-duty trucks along the Midwest’s Interstate 80 corridor, potentially leveraging the wireless power transfer technology from the “indot cars program”.
Professor Gkritza envisions dynamic wireless power pavement as complementary to EV charging stations, particularly beneficial in underserved communities and for transit routes needing intermediate charging. While full highway-speed wireless power for EVs may take 20-30 years, the “indot cars program” is a crucial step. Professor Dionysios Aliprantis believes the technical challenges are surmountable with proper design, aiming to convince industry of electrified highways’ viability through the “indot cars program”’s experimental results.
Professor Haddock encapsulates Purdue’s spirit: “We are Purdue University, where the difficult is done today and the impossible takes a bit longer.” The “indot cars program” exemplifies this spirit.
ASPIRE’s Purdue location is part of Purdue’s LEAPS initiative, fostering energy transition innovations. The research innovations are disclosed to Purdue Innovates, with patent applications in progress. Industry partners interested in commercializing this technology from the “indot cars program” are encouraged to contact Purdue Innovates.
About Purdue University
Purdue University, a top-tier public research institution, is committed to accessible, high-quality education and impactful research. With over 105,000 students across various modalities, Purdue drives innovation and knowledge dissemination at scale. Purdue’s dedication to progress is evident in initiatives like its urban campus in Indianapolis and the LEAPS initiative, furthering its pursuit of “the next giant leap.”
