New Technology for Hybrid Car Motors Leaves Rare Earth Behind

There was a time when the hybrid car was considered the coolest thing on the block. Its electric motor, which utilized rare earth minerals – something that was once found in plentiful supply in many parts of the world – seemed like the simple answer to a dependence on fossil fuels.

Electric vehicles are still in growing demand. But China’s announcement last summer that it would reduce its mining of rare earths (China currently generates more than 90 percent of the world’s usable supply) and the increasing cost of the minerals have forced manufacturers to rethink their design of the conventional electric motor.

And there has been no short supply of innovators for the task. Researchers throughout North America have come up with possible prototypes that get around the use of the precious and environmentally costly magnets that are produced from rare earth. Instead, the prototypes rely upon what is called a switched reluctance motor (SRM), a system that was developed (in crude form) in the early 1800s. With rare earth minerals now at risk, there has been increasing interest in resolving motor’s main shortcomings, which include acoustic noise and torque ripple.

In November of this year, U.S. electric car manufacturer HEVT was awarded the National Grand Prize and $25,000 at the Cleantech Global Open Forum for its patented version of a switched reluctance motor. HEVT is said to have overcome the acoustic and structural drawbacks of this particular type of motor.

“HEVT’s game-changing motor technologies leverage smart software with optimally designed hardware to empower the next generation of electric motors,” said HEVT’s CEO Heidi Lubin in a recent Cleantech press release. Benefits will include “lower initial and total cost of ownership” and the increased performance of SRMs.

HEVT, which is based in Chicago, works in concert with the University of Texas at Dallas and General Atomics to design electric motors that don’t use rare earth.

It received funding through the U.S. Department of Energy ARPA-E program, which awarded it $3 million in May to explore the feasibility of a SRM prototype.

The ARPA-E program, which was approved this May, has also provided grants to several other companies and research entities, such as Baldor Electric Company, which was awarded $2 million to develop a new type of traction motor that is said to be lighter and more efficient in torque delivery.

The use of magnets in conventional motor design, however, hasn’t been totally discarded. The University of Alabama is working on developing nano-structure magnets that are designed from composites made of iron and manganese (and rare-earth free) that can be used in hybrid car motors as well. Its research is funded in part with an $823,000 grant from the ARPA-E program.

QM Power, based in Missouri, is following a similar lead, with the development of its own iron-composite magnets. It touts advanced production techniques, redesigned motor control characteristics, and higher horsepower as some of the benefits of its compact design.

In November, after announcing that it would be cutting back the mining of its valuable rare earth, China appeared to change its mind, and announced that it would be providing subsidies for its rare earth producers. But the change in direction may have come just a bit too late for hybrid car manufacturers. This year’s impressive line-up of electric motor prototypes offers hope for a more sustainable means of producing hybrid cars.

Image courtesy of NASA Earth Observatory (Public Domain)