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Electric Roads: America’s Transportation Future?

21 October 2012
Published in Technology
Written by  Kim Schuske
Electric Roads: America’s Transportation Future? Energy Dynamics Lab

Imagine driving on I-80 from Salt Lake City to San Francisco and never stopping for gas. Or breathing clean air, even in winter. USTAR researchers at Utah State University are working on a technology they hope could one day make that fantasy a reality.

Every time we get in our cars, turn the ignition and go about our business, we’re adding to the Wastach Front’s notorious air pollution. And it’s causing major health problems. In fact, pollution contributes to 1,000 - 2,000 premature deaths each year, according to Dr. Brian Moench, Director of Utah Physicians for a Healthy Environment. “Children are actually of particular concern because for example with regards to their lung, they’re in a stage when their lungs are growing and developing very rapidly. And if they’re exposed to more air pollution, they may actually never reach their full adult lung capacity.”

It’s estimated that 50-60% of Wasatch Front pollution is caused by vehicles. Plug-in electric cars like the Nissan Leaf, which have no tail pipe emissions, hold some promise for reducing toxic smog. But Wesley Smith says electric cars are expensive and batteries are inefficient. “If it weren’t for the limitations of the battery, we would all be driving electric vehicles today. They are clearly the weakest link. They are heavy, they are costly, they have limited range.”

Smith is the business director for the Energy Dynamics Lab at Utah State University. He says scientists are developing a new technology that would allow electric cars to travel hundreds of miles and circumvent the need to plug in and charge up. “If you look at a new model instead of carrying around these energy storage devices on every vehicle, if you can transfer electricity as the physicists would say in its purest form, from a power plant, through the road, and into the vehicle, you eliminate almost all of those battery limitations.”

Researchers at the Energy Dynamics lab and USTAR are helping to develop a system to wirelessly charge electric cars while they travel over roads. Smith says electric roads could reduce battery size by as much as 85%, which would also reduce the cost – to consumers -- of an electric car. “You would electrify the main roads, but you would still have these smaller battery packs that would get you up into your neighborhood and then back down from your neighborhood back down onto a main road.”

It’s a revolutionary idea, but how close is it to reality? The technology to wirelessly transfer electricity is called inductive power transfer. It’s been around for over a hundred years. It’s the same technology that allows you to power up an ipod or an electric toothbrush by setting them on a charger rather than plugging them directly into an outlet. Hunter Wu is a research scientist at the Energy Dynamics Lab. “Basically how it works is we take an electrical source input and convert that to a high frequency magnetic field. Now that magnetic field jumps through an air gap and a receiver will receive this magnetic field and convert it back to electricity to recharge your battery.”

The technology to charge personal devices is limited since they have to be within a fraction of an inch from the charger. But Wu, while a graduate student in New Zealand, helped to develop a more advanced system that transfers power over a 12-inch or even larger air gap. The new more efficient system makes it possible to charge electric vehicles. “We can transfer roughly 40 kilowatts per vehicle, so that’s more than sufficient to power any electric vehicle traveling at 75 miles per hour on an interstate. In terms of efficiency, were looking at transmission efficiencies of about 90% efficiency. So it’s going to be very efficient. It’s going to be very comparable to even our power transmission grid,” says Wu.

The idea is to bury charging pads under pavement in parking lots, garages, and roads. And while the technology sounds futuristic, there are already a number of demonstration projects. A tram in a South Korean park is powered by wireless electricity. Only 16% of the one and a half mile road has to be electrified for the tram to run. Now the Energy Dynamics Lab has teamed up with labs in South Korea, New Zealand, and the Oak Ridge National Labs in Tennessee to develop the first demonstration project in the US.

Wesley Smith, business director for the Energy Dynamics Lab, says the first place to start is with a bus or trolley line. For that type of project the price is right. He says a high-density transit route with five buses will cost around 20% less with the wireless system than diesel or gas powered buses over their lifetime. “And what’s compelling about that is that most green technologies can’t survive in the current market place without subsidies. But we feel pretty strongly that these cannot only survive but can ultimately save a forward looking transit authority quite a bit of money.”

Smith says there’s been some interest around the country including in Utah. Craig Dearden is chair of the Wasatch Front Regional Council, which plans transportation projects for the valley. He says he doesn’t know much about the technology. But his group is always looking for transportation alternatives and would be interested in learning more. “The cost of electricity has to be less than the cost of diesel over the long run and so yeah it’s something that we’re going to have to look at.”

Despite promising advances, there are still modifications needed to make the system more efficient, safe, and cost effective before it’s ready to be widely implemented. And switching from oil and gas to electricity that’s generated from coal isn’t necessarily clean. But Jeff Muhs, director of the Energy Dynamics Lab, says he’s confident these hurdles can be overcome. “It’s much easier to scrub a single power plant than it is 250 million cars. In other words you can invest in a technology to reduce the emissions from a power plant because it is all centralized.”

While using wireless electricity on some local transit routes may make sense, electrifying highways across the country would require a huge investment by the federal government. Muhs says their goal at the Energy Dynamics Lab is to come up with big ideas about how to create and use energy in the future. He adds that the only way for the US to truly decrease its dependence on foreign oil and clean up the air is if federal and local governments start thinking big as well.

This story originally aired 2/14/11

UPDATE: WAVE Technologies has obtained a federal grant to fund a pilot project that will use the wireless transfer system to charge University of Utah shuttle buses. Wesley Smith, now the CEO of WAVE Technologies, hopes to have the project up and running early next year, 2013.

A demonstration shuttle has already begun at Utah State University.

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