Unlimited Range EV? Power from Tires!

August 27th, 2011 by Breath on the Wind

Nikola Tesla created a device for wireless energy transfer using high frequency electromagnetic radio waves over 100 years ago. Ultimately, we will be using wireless transfer of energy to at least charge electric vehicles. Many researchers are proposing to power electric vehicles wirelessly giving us unlimited range. Often suggested is induction using the alternating current in one coil to induce electricity in another coil. This is the same technology that is used in transformers, like the power supply for your laptop battery. It is also used to wirelessly charge mobile devices and has been seen in wireless toothbrush chargers.

Click for larger image

Masahiro Hanazawa at Toyota Central R&D Labs and Takashi Ohira at Toyohashi University of Technology speculate that the steel belts in tires can be used for the energy transfer and they are not using coils. Grid-supplied power is “converted into radio frequency (RF) by high-speed inverters implanted along tracks in the road. The RF voltage is applied to a balanced metal track embedded under the surface of the road. The EV picks up the RF voltage via electrical capacitance between the metal and a steel belt installed inside of the tires of the EV.”

Unlike the magnetic energy transfer of coils, RF energy uses a much higher frequency electronic circuit. These can be tuned like a radio to a specific frequency. And like radio waves, they are easily transmitted. The electrical leakage is described as “small” and infrastructure would be less expensive than using a magnetic coil system. What is unique to their research is using the steel belts of a tire as a receiver. Tesla would be proud.

Photocredit: Abode of Chaos
Source and illustration credits: Tech-Overtures

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Tags: Electricity, Energy, Masahiro Hanazawa, RF energy, Takashi Ohira, Tesla, tires as energy receiver, Toyohashi University, tuned RF energy transfer, unlimited range EV, wireless, wireless charging, wireless electric vehicles, wireless energy transfer

About the Author

Breath on the Wind We share this World; its past, present resources and our combined future. With every aspiration, the very molecules we use for life are passed to others through time and space so that each of us may be considered a Breath on the Wind. This part of the world's consciousness lives in NYC; has worked in law, research, construction, engineering; has traveled, often drawn to Asia; writes on Energy and Electric Vehicle issues and looks forward to all your comments. "If you would persuade, you must appeal to interest rather than intellect." -- Benjamin Franklin

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Asdf

You should be particularly careful when advocating wireless energy transfer, because so far there have been very few studies about its effects on human health.

If we take into account the ones about cell phones and/or WiFi, the conclusions are mixed. If we consider that some of those studies have been sponsored/influenced by the cell phone companies, then we end up with a probably negative outcome for human health.

It is not a matter to be taken lightly. Cancer rates have skyrocketed during the last decades because of our lifestyle. And the industry is not regulated enough to protect us from dangerous products…
- Anonymous
  
  I agree. I think about the same things every time I read about such a technology.
- Breath on the Wind
  
  The constant influence of chemicals (mostly petrochemical based) in our water, air and food are a far more likely source of increased cancer rates than RF in the air. Burned chemicals don’t simply disappear from the gas tank. These are known to increase cancer rates. Rather than “suspect” a source that gives inconclusive results we should begin working to correct the known “evils.”
  
  A path away from our petrochemical dependence is the EV. Unlimited range electric vehicles = clean, quiet, efficient, inexpensive private and mass transit. It is not beyond the petrochemical industry to raise doubts about competing technologies in an attempt to maintain its hold on our society. We can listen to those fears or boldly move forward away from chemical dependency.
Captain Obvious

Not gonna pass the back of the envelope calculations test. But thanks for thinking out of the box though.
- Breath on the Wind
  
  I have looked at several wireless energy transfer systems. Researchers are getting between 80 to 90% efficiency. Tuned transfer can cover remarkable distances but this system would require the least separation as the tires are already in contact with the road. Studies have shown that transmitting energy would be a cheaper method of EV adoption than by using exclusively batteries. http://www.greencarcongress.com/2010/02/nrel-study-finds-that-a-dynamic-plugin-vehicle-could-be-a-promising-technology-pathway-for-costeffec.html So I would love to see your envelope.
sola

This doesn’t seem to be too realistic.

Inverters under the road? It would take immense amount of money to convert even city roads to allow this working method. That would only be cheaper if only small road sections would need to be converted. In this case, all cars would still need to retain sizable batteries and there would be a very high energy RF transfer during the short sections (for the same charge) which I wouldn’t trust to be harmless.
- Breath on the Wind
  
  There are already EV wireless chargers for private use that are 97% efficient: http://gas2.org/2011/08/03/evatran%E2%80%99s-wireless-ev-charging-hot-spot-boasts-97-efficiency/ Google is testing them as well. http://cleantechnica.com/2011/03/24/google-tries-wireless-ev-charging/ Another step, to put such devices at more public charging stations, stops and red lights would require manufacturers install the necessary pick ups on a sufficient number of EV. The last step would be EV charging lanes on highways. You are already exposed to countless RF energy. Manufacturers claim the energy is harmless although who you trust is another matter. Microwaves are another method of wireless energy transfer but this is not completely harmless.