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How much power? At 50-60 mph about 800 watts worth.

Might be interesting to couple this to the Volt's ICE to do some extra charging and/or run accessories when it's on.


In this July 31, 2008 photo released by General Motors, a ten-year-old prototype of General Motors thermoelectric generator, which converts exhaust heat into electricity, is shown on a tail pipe in Warren, Mich. An updated version of the device, which could improve fuel economy by 5 percent, is planned to be tested in a Chevrolet Suburban in 2009. (AP Photo/General Motors, Lee Short)​

Link....

Researchers work to turn car's exhaust into power

(AP) -- The stinky, steaming air that escapes from a car's tailpipe could help us use less gas. Researchers are competing to meet a challenge from the U.S. Department of Energy: Improve fuel economy 10 percent by converting wasted exhaust heat into energy that can help power the vehicle.

General Motors Corp. is close to reaching the goal, as is a BMW AG supplier working with Ohio State University. Their research into thermoelectrics - the science of using temperature differences to create electricity - couldn't come at a better time as high gas prices accelerate efforts to make vehicles as efficient as possible.

GM researcher Jihui Yang said a metal-plated device that surrounds an exhaust pipe could increase fuel economy in a Chevrolet Suburban by about 5 percent, a 1-mile-per-gallon improvement that would be even greater in a smaller vehicle.

Reaching the goal of a 10 percent improvement would save more than 100 million gallons of fuel per year in GM vehicles in the U.S. alone.

"The take-home message here is: It's a big deal," Yang said.

The DOE, which is partially funding the auto industry research, helped develop a thermoelectric generator for a heavy duty diesel truck and tested it for the equivalent of 550,000 miles about 12 years ago.

John Fairbanks, the department's thermoelectrics technology development manager, said the success of that generator justified the competitive search in 2004 for a device that could augment or replace a vehicle's alternator. Three teams were selected to participate in the program, with GM and thermoelectrics manufacturer BSST separately working on cars and a team from Michigan State University focusing on heavy-duty trucks.

Fairbanks said thermoelectric generators should be on the verge of production in about three years.

"It's probably the biggest impact in the shortest time that I can think of," he said.

The technology is similar to what NASA uses to power deep space probes, a perk being it doesn't seem to be susceptible to wear. Probes have used a thermoelectric setup for about 30 years.

Thermoelectric devices can work in two ways - using electricity to provide heating or cooling, or using temperature differences to create electricity.

The second method is Yang's focus, and for good reason.

In an internal combustion engine, only about a quarter of the total energy from gasoline is used to actually turn the wheels, while 40 percent is lost in exhaust heat and 30 percent is lost through cooling the engine. That means about 70 percent of the available energy is wasted, according to GM.

"If I can use some of that heat energy and convert it to electricity, you can improve the overall efficiency," Yang said.

A Suburban produces 15 kilowatts of exhaust heat energy during city driving, which is enough to power three or four air conditioners simultaneously.

But it's not possible to harness all the exhaust heat a vehicle produces, so when the Suburban is cruising between 50 and 60 mph, the generator can produce about 800 watts of power, Yang said. That electricity could go to accessories such as a GPS device, DVD player, radio and possibly the vehicle's water pumps.


Yang's prototype device is to be tested in a Suburban next year. A similar prototype created by Ohio State scientists and BSST should be tested in a BMW in 2009.

The thermoelectric generator works when one side of its metallic material is heated, and excited electrons move to the cold side. The movement creates a current, which electrodes collect and convert to electricity.

While it's not clear how much the device would add to the price of a vehicle, the whole point of the research is to make it cost-effective, Yang said.

"There are several other steps that are required to commercialize the material, but we're cautiously optimistic that these steps can be carried out successfully," said Lon Bell, president of BSST, a subsidiary of Northville-based thermoelectrics supplier Amerigon Inc.

BSST also is working with Ford Motor Co. to develop climate control systems based on thermoelectrics.

Ford wants a system that would target a person's extremities when it's cold or the back of the neck in summer heat, rather than blow out a lot of air to change the temperature of the entire vehicle.

"We think we can make people feel cooler more quickly, feel comfortable more quickly, and that will translate into less power in the central AC system," said Clay Maranville, a Ford senior research scientist.

Honda Motor Co. also has supported university research into thermoelectrics, but a spokesman said the automaker doesn't have its own research program.
 

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This reminds me of the Cool Chip I use to follow.

http://www.coolchips.com/


It had great promise but they were never able to manufacture the darn thing. Perhaps when better nanotube manufacturing processes are developed we will see this make it to the market place.

Anyway, there sure is a lot of wasted heat energy coming off the ICE. The main question is if they can recover it economically. The turbo charger is such a device that has proven effective.
 

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This is related to what I've been thinking about. Imagine getting rid of the ICE all together and just having a chamber where gasoline, diesel or bio-fuel is slowly burned and the heat energy from this reaction is converted directly to electricity. Now place this chamber in a vacuum like a thermos bottle so that very little heat escapes. The exhaust would have devices like the one in the above post all along the pipe to recoup that energy and maybe even small turbines to mechanically get some of the energy of the escaping gases back too.

If we could get even 60-70% of the potential energy of gasoline to actually do work instead of generate worthless heat, think of what incredible mileage cars could get. Gasoline is a fantastic portable energy source, just we don't seem to know how to use it very well yet. I believe that research into the more efficient use of gasoline beyond the ICE is just as important, if not more important than battery and capacitor research now. However I've seen little to no research going on like this. Everything seems to be about how do we squeeze a little more efficiency out of the ICE. The ICE has run it's course and served us well, but it's time to send it to the museum next to the steam engine.
 

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Maybe the volt will come with a wind turbine after all!


Now darthvader, don't make the mistake you are making. We are not talking about free energy here. We are talking about waste energy recovery. This is a big topic all over the world. The average ICE is only 30 percent efficient at converting the energy of gasoline to usable work. The remaining energy is just wasted (no usable work is performed). Capturing that wasted energy increased the efficiency of the system, at a cost. The cost of the equipment, complexity, etc.

For example, Dean Kamen, the engineer who invented the Segway, has developed a machine to distill water that is many times more efficient than anything before. It collects and reuses most of the heat energy expended in the distillation process. Here is the article:

http://www.allwaterpurification.com/dean-kamen-water-purifier.html


Not free, just more efficient.
 

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DaV8or, your idea just might work… Take a look at the following site:
http://www.hiroshima-u.ac.jp/en/top/research_HU/researchnow/no4/index.html

Although 98 to 99 percent of the latent energy of gas is converted into heat in the ICE combustion chamber, only 20 percent or so is used to propel the car. The rest escapes through the tail pipe and the radiator. Atkinson cycle design is one way to utilize the thermal energy more efficiently, but you have the trade-off of poor power/weight ratio.
 

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Now darthvader, don't make the mistake you are making. We are not talking about free energy here. We are talking about waste energy recovery.
Don't worry, I wasn't making that mistake at all. I just thought it would be funny if after all the threads here about free energy wind turbines on cars GM actually went and put a little turbine on the exhaust pipe. Or an exhaust heat collector, whatever.

We should really get a sticky thread about this stuff so we don't have to constantly correct people about free energy schemes. Some of the really crazy people would post threads anyway but it might cut down on it a bit.
 

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Too bad there's no mention of cost. 800 watts is about the full output of a 57amp alternator.

I can see all sorts of aftermarket and retrofit potential for something like this. All depends on cost though.
 

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nice

That'd be a pretty awesome addition to the volt so long as it could be made cheaply and was reliable. get another 800 watt/h when the ice is running. Definitely something you want to put as close as possible to the exhaust port. I wonder how much it'd increase it's efficiency by giving it a water jacket and it's own pump and small radiator or at least aluminum cooling fins; since the more heat that you transfer through the elements the more energy it makes. You would also probably want to make it the outer shell of a catalytic converter; since the restriction/pressure differential it creates makes it the hottest part of the exhaust.....unless you have a turbo.
 

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Auto Exhaust Can Generate Thermoelectric Power

About 40 percent of the energy from gasoline or diesel fuel is wasted as exhaust heat. If you can convert some of that heat to electricity, it can provide electric power for automotive accessories, relieving some of the burden from the engine resulting in better fuel economy. The device that performs this conversion is a thermoelectric generator and GM has been working on developing one to either assist or even replace the vehicle’s alternator.
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