Test: Alternator vs. no alternator = 10% MPG gain @ 70 km/h

[Cd]

Originally Posted by Newton

you could produce electricity using the engine's heat by utilizing peltier plates. VirtualVillage.com i've got two 12v 400w plates on the way, i just have to find a spot that gets warm but doesn't exceed the plates max temp and mount them with some thermal grease somehow and put a heatsink/fan on the otherside to cool down the cold side. Not only does using the engine's wasted heat to produce it's electricity increase the overall efficiency of the engine but could possibly completely replace the alternator. Just gotta make sure to put a diode in the line so that when the temperature gradient is gone they don't become heat pumps.

Wow ! What a great idea.

Would it work ?

[Newton]

i'll be sure to keep you all posted, i'll start a thread probably when i do it seeing as how there's a bit of wiring needing to be done so that when the temperature gradient is gone they don't pull power from the battery and become heat pumps (one side gets hot the other side gets cold, they're kinda inefficient so that keeps them from being used for heating/air conditioning) the two i have on the way (probably another week or two) are 20A @ 12v each so if i wire them in parallel then i can get 40A @ 12v. The replacement alternator for my geo will produce 50A and i doubt that it's producing that constantly so i imagine at 40A i'll have some extra juice to use for the rest of the car. On paper this should work, only issues i have to tackle first is that they cannot exceed 68C (154F) so i'm going to go pick up a laser thermometer, i might have to bolt a plate above the engine at the correct height that it will get close to but won't exceed 68C

[orange4boy]

Sounds interesting but the literature states:

"Capable of generating electricity when one side is kept cool and heat is applied to the other"

It's not clear in the specs how much electricity they produce when working in reverse.

I hope it works because that would be a fantastic way to power a vehicle. These could be your radiators. Can one get a 150 degree thermostat? I was just wondering if you have any experience or examples of what you are proposing.

(Fingers crossed)

Added link: http://en.wikipedia.org/wiki/Automot...ric_Generators

[Curly1]

Why don't you use an underdrive pulley. From your tests it is obvious that the Alternator does have a significant draw. A solar charger would help some but I do not think they put out enough to replace alternator. Still anything you can do to reduce the load will help you.
Most underdrive crank pulleys slow the alternator, water pump and airconditioner to free up some power and increase mileage.
I do not think it is a good idea to completly eliminate the alternator but you can limit the horsepower it takes to run it and the electric draw need to charge batteries.

[Newton]

I don't have any experience but I do have two of these puppies on the way for me to experiment with. I do know however that they are very inefficient and that's what keeps them from cooling our food and heating our homes. It's amazing that this concept hasn't really caught on in the major automotive manufacturers. With the ability to recollect the energy lost from heat in the horribly inefficient internal combustion engines (ICE) we could see some very good numbers. Or even use the electricity to power a small DC assist motor making a small Parallel hybrid drive system. Someone in the diyelectriccar forum brought up the fact that you could easily put a small dc motor in place of the a/c compressor and use the accessory belt to assist the engine (maybe ~9kw). That would most certainly boost FE a great deal probably.

[Newton]

We did some research on the peltier plates and we found that they're made for either cooling/heating/generating and upon further research i found some thermoelectric generating peltier plates but they are pretty expensive. $70 for 1 plate that produces 2.5watts at 3.3volts. they'll do discount bulk orders but it's still gonna be pricey. i'll bet that theres a chinese factory somewhere that will sell them to me dirt cheap. if i find anything better i'll post it.

[Frank Lee]

"It's amazing that this concept hasn't really caught on in the major automotive manufacturers."

"...upon further research i found some thermoelectric generating peltier plates but they are pretty expensive. $70 for 1 plate..."

I think you have answered your own question.

[Newton]

lol yeah but the company i got the price from (Hi-Z Technology, Inc.) is working with Clarkson University and NYSERDA to develop a drop in model for the GMC Sierra pickup truck. If the major auto manufacturers really wanted to do this they could easily produce the modules for dirt cheap (kinda like lithium batteries now, no mass production so they're expensive). They're only expensive on the small scale which is where it is right now. So yeah lol in a way i did answer my own question but then again it just raises more questions about why if the automotive industry knew about this, and nissan motors made a working prototype in the early 90's, why they haven't pursued it further. I could point my finger to the oil companies and it may have been them keeping ICE from getting more efficient but it probably lies in the lazy hands of the Managing bodies of the corporations. I apologize for digressing this thread.

[Frank Lee]

OK I could be wrong, haven't put a whole lot of thought into it, but perhaps the peltiers wouldn't be as capable of supplying the vehicles' electrical needs as the ol tried n true, relatively inexpensive alternator systems, even if the peltiers do come down in cost with further development and acceptance. For instance, there is probably no charging when cold... on a vehicle that does frequent short trips would the charging system keep up? The manufacturers pretty much have to design things for the worst case scenario.

[Newton]

the one Hi-Z is developing is 300w which at 12v is only 25amps but maybe that's all the gmc sierra needs, not sure. but one could easily fan out the exhaust tube to create more surface area and put a peltier farm easily replacing the alternator. they don't produce anything until the engine gets warm but they do continue to produce after the engine is off. that might make up for the lag on startup. the alternator is tried and true but so are peltier plates. they use them on satellites to pump the suns "heat" so they don't melt and they use them because they run indefinitely under ideal conditions. you have a very good point with short trips but how hot is the actual exhaust as soon as the engine starts up? if the peltier plates were literally the wall of the exhaust then they would be in contact with the exhaust temperatures immediately, i dunno, that's just me speculating but sounds like it might work. but with all said unless you're a millionaire then we just have to play the waiting game.