"New" Technology Charges Batteries using Heat

paulstamser
paulstamser Solar Expert Posts: 86 ✭✭✭
Here it is! New technology that possibly will allow us to charge our stand-alone PV system batteries using heat from a WOOD STOVE during long winter cloud events and short-day periods!

If successful, such thermoelectric modules could do away with the need for a fossil fuel backup generator. This is a dream I've had since going PV in 1988. Maybe the dream is about to be realized.

Will this take off or be something we hear about once and never hear about again?

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Note, article is the next post following this one:

Comments

  • paulstamser
    paulstamser Solar Expert Posts: 86 ✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    First post got messed up and won't edit properly. Here's the article:

    =======================

    Body heat could charge your cellphone [plus lots more!]

    By Wolfgang Gruener
    Friday, January 11, 2008 12:45

    Berkeley (CA) – Remarkable research findings on energy conversion have been published in the most recent edition of Nature: Scientists believe to have discovered a much more efficient way to use silicon to convert heat into electricity – for use in a variety of products ranging from cars to portable electronics.

    Imagine a time in which you would not have to plug in your cellphone or iPod over night to recharge the battery. Instead you would power and charge a device simply by wearing it close to your body. The concept of converting waste heat into electricity isn’t exactly new, but it never really materialized due to efficiency hurdles. Now, scientists from the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley think they may have found a key increase the conversion efficiency by a factor of 100.

    In contrast to previous silicon nanowire-based converters, researchers have used what they describe as “rough” silicon nanowires. The material is created in a process of “electroless etching” in which arrays of silicon nanowires are synthesized in an aqueous solution on the surfaces of wafers. According to the paper published, the “technique involves the galvanic displacement of silicon through the reduction of silver ions on a wafer’s surface”. In contrast to common silicon process methods, this technique results in vertically aligned silicon nanowires that apparently feature exceptionally rough surfaces. And it is that roughness that is believed to be critical to the surprisingly high thermoelectric efficiency of the silicon nanowires.

    “The rough surfaces are definitely playing a role in reducing the thermal conductivity of the silicon nanowires by a hundredfold, but at this time we don’t fully understand the physics,” said Arun Majumdar, a mechanical engineer and materials scientist with joint appointments at Berkeley Lab and UC Berkeley, who was one of the principal investigators behind this research. “While we cannot say exactly why it works, we can say that the technique does work,” he said.

    While the research is far from being completed, the scientists already believe that the results could allow us to use energy much more efficiently. Potential applications of this technology include DOE’s hydrogen fuel cell-powered “Freedom CAR,” and personal power-jackets that could use heat from the human body to recharge cell-phones and other electronic devices.

    “You can siphon electrical power from just about any situation in which heat is being given off, heat that is currently being wasted,” said Majumdar. “For example, if it is cold outside and you are wearing a jacket made of material embedded with thermoelectric modules, you could recharge mobile electronic devices off the heat of your body. In fact, thermoelectric generators have already been used to convert body heat to power wrist watches.”

    On a slightly larger scale, conversion modules could also be used to convert the heat from automotive exhaust into supplemental power for a Freedom CAR-type vehicle, or provide the electricity a conventional vehicle needs to run its radio, air conditioner and power windows. Above that, thermoelectric modules could eventually be used in co-generating power with gas or steam turbines, the researchers believe.

    The meaning of the discovery will depend on whether these rough nanowires will be efficient enough to make commercial sense. However, if we consider that nearly all of the world’s electrical power, approximately 10 trillion Watts, is generated by heat engines, giant gas or steam-powered turbines that convert heat to mechanical energy, we know that much of this heat worth another 15 trillion Watts of electricity is not converted but released into the environment. It doesn’t take much to see that there is an enormous potential of increased efficiency in this discovery.

    http://www.tgdaily.com/content/view/35579/113/
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    http://www.nature.com/nature/journal/v451/n7175/abs/nature06381.html

    is the "source", which is just a "letter"

    and I qoute:

    "For such nanowires, the lattice contribution to thermal conductivity approaches the amorphous limit for Si, which cannot be explained by current theories"

    Translation, we did a test, we have a result that doesn't fit known science so it must be some unknown magic we don't understand vs. a flawed test.

    ever hear of this? http://en.wikipedia.org/wiki/Cold_fusion
  • paulstamser
    paulstamser Solar Expert Posts: 86 ✭✭✭
    Re: "New" Technology Charges Batteries using Heat
    http://www.nature.com/nature/journal/v451/n7175/abs/nature06381.html

    is the "source", which is just a "letter"

    and I qoute:

    "For such nanowires, the lattice contribution to thermal conductivity approaches the amorphous limit for Si, which cannot be explained by current theories"

    Translation, we did a test, we have a result that doesn't fit known science so it must be some unknown magic we don't understand vs. a flawed test.

    ever hear of this? http://en.wikipedia.org/wiki/Cold_fusion

    C'mon, don't burst my dream, okay?

    Just because they don't know how this thing works doesn't mean it's been FAKED!

    At least I hope not...

    If we could generate electricity to charge our batteries from a wood stove it would be a REAL breakthrough and make stand-alone systems like mine nearly perfect because I'm burning firewood and producing TONS of waste heat 24/7 anyway that goes out the chimney!

    And from what the article states, it isn't just for little cellphone batteries, but also for larger applications.

    Yippee!
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: "New" Technology Charges Batteries using Heat

    There is a recent thread discussing thermopiles and wood stoves to extract heat for electricity here....

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • paulstamser
    paulstamser Solar Expert Posts: 86 ✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    Looks like the break-through to get electrons from wood us PV & firewood homesteaders have been waiting for might be coming!

    If electricity from heat can work off a car's exhaust pipe some juice should be extractable from a wood-burning chimney going 24-7 all winter long including at night.

    Do I have to build my own?

    ==========

    Heat from car exhaust could improve mileage
    August 11, 2008 7:55 AM PDT

    Researchers are trying to find a useful outlet for cars' waste heat--namely their electrical load.

    General Motors and BMW plan to test devices that will convert excess heat from a car's motor into electricity next year, according to an Associated Press report Sunday.

    GM has built a prototype, a metal-plated device that will fit around an exhaust pipe. Researchers told AP that they expect that it could improve fuel efficiency in a Chevrolet Suburban by about 5 percent, or 1 mile per gallon. The improvements would be greater in smaller, more fuel-efficient vehicles.

    Auto companies are working with thermoelectrics researchers at Ohio State University to improve the efficiency of existing materials by producing an electric current from differences in temperature.

    Researchers estimate that 30 percent to 40 percent of the heat generated from a car's engine is used. The rest is lost through exhaust or engine cooling.

    Thermoelectric devices are already used in space exploration and in more commonplace applications, such as like cooling car seats. But research in the area, some of which was abandoned decades ago, is perking up as businesses explore new energy efficiency technologies.

    (and snip:)

    Besides automakers, a couple of other companies are trying to commercialize thermoelectric technology.

    Promethean Power is developing a solar-powered refrigerator that will use a thermoelectric module for cooling.

    http://news.cnet.com/8301-11128_3-10013303-54.html

    Similar article on autobloggreen adds:

    "When cruising between 50 and 60 mph, the generator can produce about 800 watts of power..."

    I'd be thrilled if my chimney could produce 50 watts 24/7 all winter long!
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: "New" Technology Charges Batteries using Heat

    If we all think inside the box we all remain in the box. Leaps of faith are often required to leave the box, and when they do some Oil Company or Power Company is waiting to buy the technology.

    SG is right to be skeptical but we all need a leap of faith from one time to another.

    Was the iconic MX60 born from thinking in the box....I doubt it.

    Many can and will join the new space and improve on a leap of faith, but you have to have the quality, strenght and balls to jump in the first place.8)

    No leaping no new discoveries.

    Paul follow your passion mate ! It will come home to roost some day if you want it, then I guarantee someones working on it. :D NTD
  • nigtomdaw
    nigtomdaw Solar Expert Posts: 705 ✭✭
    Re: "New" Technology Charges Batteries using Heat

    The only out the box thinking I came up with was the BarSteward system ....TM.... nigtomdaw and it never never got 2 production,:cry: nither did my guaranteed 50% energy fuel bill reduction kit at $9.99 including all tools,

    Its a simple process your kids could do it ;)
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    So far, thermoelectric systems produce a dozen watts for thousands of $$. When they can produce hundreds, then I will start shopping.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • System2
    System2 Posts: 6,290 admin
    Re: "New" Technology Charges Batteries using Heat
    nigtomdaw wrote: »
    If we all think inside the box we all remain in the box. Leaps of faith are often required to leave the box, and when they do some Oil Company or Power Company is waiting to buy the technology.

    I'm just curious, what "out of the box" technologies have the oil and power companies bought up that they're keeping from us?

    Bad Apple
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    the 100 MPG carb, the engine that runs on water, rocket belts, flying cars, zero point machines ... the list goes on.

    [edit] forgot the $0.50W/ 30 year solar PV panels, with water heating loop in them
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • lamplight
    lamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    well, solar power for a fossil fuels energy company some years ago would have seemed pretty whacky.
  • paulstamser
    paulstamser Solar Expert Posts: 86 ✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    Check out these thermoelectric modules. 20 watts for $210. BUT, when you add in the additional parts you need and the DC to DC voltage converter to boost output up to a useable 14 volts, it ain't as cheap as I'd like it to be for what is essentially an experiment. But if somebody would successfully make one of these work off their woodstove chimney and reliably get near 20 watts, I'd probably take the bait. I'm ready, but still in the wait-and-see stage.

    You'd think that the interface of a hot woodstove chimney and the cold outdoor winter air would provide a good temperature gradient to make these things work fairly efficiently.

    http://www.hi-z.com/store.php
  • lamplight
    lamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    that seems reasonable if it works. and theyre so small. 3"??? i would make a mess of this doing it myself i bet. id pay $1000 for a few of these on the side of my wood stove. wonder if you can use one dc to dc converter for a bunch of them or not. so, the big question, whos going to test it out? id think this would make bigger news if legit.
  • paulstamser
    paulstamser Solar Expert Posts: 86 ✭✭✭
    Re: "New" Technology Charges Batteries using Heat
    lamplight wrote: »
    that seems reasonable if it works. and theyre so small. 3"??? i would make a mess of this doing it myself i bet. id pay $1000 for a few of these on the side of my wood stove. wonder if you can use one dc to dc converter for a bunch of them or not. so, the big question, whos going to test it out? id think this would make bigger news if legit.

    The site selling them looks legit. Maybe they haven't caught on yet because users of a combined PV & woodstove system is such an obscure group.

    The DC to DC converter they sell for $100 has a pretty low output, but in small system like mine it would be useful as heck (see below).

    I suppose the first step would be to put a thermometer in the chimney see how hot the flue gases are during various burn levels and see if the exterior chimney has enough heat to make this thing work. If not, you'd have to bring it down to the stove itself like you said. Somewhere on the site they mention "woodstoves" as one application. Maybe this is closer than we think and somebody's has got to take the plunge.
    Description
    The HZ-12-24 DC/DC converter is designed to handle input voltages between 1.8 volts and 9 volts and output currents up to 2.5 amperes at voltages up to 15 volts. The output current at a particular output voltage depends upon the input voltage, and can be estimated from the input power, taking into account an efficiency of about 87%. The HZ-12-24 converter is well suited as a battery charger and provides a charging current proportional to the input voltage. An output voltage limiter is provided to prevent battery overcharging.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: "New" Technology Charges Batteries using Heat

    Just be careful with soot and creosote... These devices cool the combustion gases in the flue and could condense flammable materials around the "generator" and flue. Setting you up for a flue/chimney fire later.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Telco
    Telco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat
    BB. wrote: »
    Just be careful with soot and creosote... These devices cool the combustion gases in the flue and could condense flammable materials around the "generator" and flue. Setting you up for a flue/chimney fire later.

    -Bill

    No problem, strap it to a pipe, then run water through it with a very short run from the stove. Would just need the loop to extend a foot or so away. Let the fire heat the pipe of water directly, no effect on chimney temps. Probably wouldn't even need a pump to run this, perhaps just a one way check valve to make the water move only in one direction. If you designed it right, you could have a single stove dedicated to this outside the house, with multiple devices hanging off it to generate power. The colder it gets outside, the more electricity it would generate...
  • mike95490
    mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    Hot water, is not hot enough to run the thermopile generators - they need about a 400F difference, to make their .5W
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • Telco
    Telco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat
    mike90045 wrote: »
    Hot water, is not hot enough to run the thermopile generators - they need about a 400F difference, to make their .5W

    "On a slightly larger scale, conversion modules could also be used to convert the heat from automotive exhaust into supplemental power for a Freedom CAR-type vehicle, or provide the electricity a conventional vehicle needs to run its radio, air conditioner and power windows. Above that, thermoelectric modules could eventually be used in co-generating power with gas or steam turbines, the researchers believe."

    This is something new, not the old stuff. They claim that they can pull enough power from the exhaust to run a modern gasoline engined vehicle, this means it would need to be able to generate as much as 80 amps at 12V. 960W is quite a bit more than .5 watts. The temp difference might be an issue though, as exhaust can run some 400 degrees. Perhaps another liquid medium like thermal oil then, if water under pressure can't get hot enough.
  • System2
    System2 Posts: 6,290 admin
    Re: "New" Technology Charges Batteries using Heat
    Telco wrote: »
    ... 960W is quite a bit more than .5 watts. ...

    960 watts is 1.3 horsepower. As a rule, 1/2 pound of fuel per horsepower per hour is consumed in an internal comustion engine running optimally and seven pounds per gallon. One gallon gasoline equivalent of energy produced using those numbers is 10.8 hours at 960watts per gallon. Not much in the big scheme of powering vehicles down the road. Of course, multiplied by millions of cars on the road it is something, but percentage wise, pretty miniscule.

    Cheers,

    Bad Apple
  • lamplight
    lamplight Solar Expert Posts: 368 ✭✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    i didnt read the part about needing a major temp differential between the inside and outside. stove temps reach 400deg no problem but the outer temp needing to be alot cooler (inches away?) would require some serious ingenuity, thats the kind of thing needs to be packaged and sold with it, give me a break. i suppose some kind or metal tube vacuum /custom fitted to the cold side, run directly outside to open air would be a good thing. they should sell it that way with a flexible metal tube - or something ;):confused::roll:
  • Telco
    Telco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat
    Bad Apple wrote: »
    960 watts is 1.3 horsepower. As a rule, 1/2 pound of fuel per horsepower per hour is consumed in an internal comustion engine running optimally and seven pounds per gallon. One gallon gasoline equivalent of energy produced using those numbers is 10.8 hours at 960watts per gallon. Not much in the big scheme of powering vehicles down the road. Of course, multiplied by millions of cars on the road it is something, but percentage wise, pretty miniscule.

    Cheers,

    Bad Apple

    I don't see where you are going with this, unless you are looking at the gasoline saved by removing the alternator. An alternator will pull as much as 10HP off the engine, most engines see about a 5HP load. How much power an ICE produces would not matter to this device as all it will care about is how hot the exhaust is vs how cold ambient air is. And, this device will need to be able to produce that 80 amps or so at 12V in the desert, in August, at noon, in order to be viable on a production vehicle, so the heat differential doesn't have to be that great. If it's not able to meet this requirement then it won't pass the automaker's preproduction testing. As this is the case, this device could be adapted to a wood fired stove, probably pretty easily. This device would also work better in the winter than the summer, when solar panels are producing their least.

    Going to have to see one in action though, all this is just guessing based off what I've read here. Looking forward to it.
  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    hmmm, i think there'd be something wrong with that alternator if you lose that much hp. if memory serves rightly, 1hp=746w or somewhere around that. even if the alternator was 100a and was capable of sustaining that at 12v you may see a 2hp drop tops for 100a x 14v=1400w or just under 2hp.
    if you really want to try your hand at it go to the melcor site. you will need several of the thermoelectrics designed to produce power to be in series. proper heat sinking will also be needed and this will be large and expensive when dealing with many devices needing very low thermal resistance. they did have a page that you could input your requirements and it will give the results.
  • Brock
    Brock Solar Expert Posts: 639 ✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    I am with Niel, if I recall correctly a standard alternator is about 50% efficient. So even pushing out 100 amps at 12v or 1200w that’s about 2 hp, assuming the alternator is 50% efficient, then the max load on an engine is about 4 hp.

    For a long time I ran without an alternator and instead used a 12v 245 amp battery, at 1200w inverter and 55 amps charger connected to the starting battery. I typically saw a draw of about 120 watts or 10 amps. That’s maybe 1/8 hp even considering alt losses. The max my car would ever pull was running the glow plugs or coolant glow plugs in cold weather (stayed on until the water temps hit 100F) or 80 amps at 12v on top of the 10 amps or 90 amps or about 1200 watts.
    3kw solar PV, 4 LiFePO4 100a, xw 6048, Honda eu2000i, iota DLS-54-13, Tesla 3, Leaf, Volt, 4 ton horizontal geothermal, grid tied - Green Bay, WI
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: "New" Technology Charges Batteries using Heat

    Automotive alternators are only 50-62% efficient (per Wiki cite)--which agrees with what I learned many decades ago of approximately 50% efficiency for a belt driven automotive alternator (no cite--high school automotive shop teacher?).

    So--for 2 hp output, one would expect about a 4 hp load (for a 70 amp alternator...

    IIRC, for my now 10 year old Ford P/U, I got the 130 amp version...

    130a*14v * 1/50% * 1/746w per hp = 4.9 HP

    These guys probably will not output 130 amp continuously for very long though...

    Regarding gasoline--roughly 6.25 lbs per gallon... I have used the 1/2lb of gas per HP * Hour when double checking generators and other motors (piston engine aircraft)... Seems to work pretty well.

    For example, using a Prius running 55 MPH for 1 hour at 55 Miles Per Gallon (easy numbers) = 1 gallon or 6.25 lbs of fuel.

    6.25lbs/0.5 gals per HP*Hour=12.5 HP average engine output.

    My Honda Van running at 75 MPH and ~25 MPG with A/C as needed...

    (75 miles in 1 hour / 25 MPG) * 6.25 lbs per gallon * 1/0.5 HP*HR per gallon = 37.5 HP*Hours

    1970 old P/U 65 MPH, 17 MPG...

    65 miles in 1 hour / 17 MPG) * 6.25 lbs per gallon * 1/0.5 HP*HR per gallon = 47.8 HP*Hours

    -Bill

    PS: See Brock had fast fingers today...
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: "New" Technology Charges Batteries using Heat
    Telco wrote: »
    I don't see where you are going with this, unless you are looking at the gasoline saved by removing the alternator. An alternator will pull as much as 10HP off the engine, most engines see about a 5HP load. How much power an ICE produces would not matter to this device as all it will care about is how hot the exhaust is vs how cold ambient air is. And, this device will need to be able to produce that 80 amps or so at 12V in the desert, in August, at noon, in order to be viable on a production vehicle, so the heat differential doesn't have to be that great. If it's not able to meet this requirement then it won't pass the automaker's preproduction testing. As this is the case, this device could be adapted to a wood fired stove, probably pretty easily. This device would also work better in the winter than the summer, when solar panels are producing their least.

    Going to have to see one in action though, all this is just guessing based off what I've read here. Looking forward to it.

    I'm not going anywhere with this other than stating my opinion that using an alternative source for electricity generation on an automobile will save very little fuel.

    Bad Apple
  • Telco
    Telco Solar Expert Posts: 201 ✭✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    I wasn't sure exactly how much an alternator will pull off an engine, but I do know that it pulls at least 5HP depending on the electrical load of the vehicle. It's enough that several automakers have developed intelligent alternator control systems that control when the alternator produces power, claiming a 4 percent increase in fuel efficiency. As cars get more electro-intensive, an alternator that puts a 10HP draw may become a low draw system assuming that the car remains an ICE powered vehicle of some sort and not an all electric rig. In that article it mentions that a midsized car currently use 3500W of power to operate all systems normally. Seems pretty high though, since most modern vehicles come with 100 to 140 amp alternators, which is 1200 to 1680 watts. Wonder where they got that from?

    On an automotive performance board I frequent, we determined that the electric fans I was using on one of my rigs was responsible for an estimated 2.5HP load vs the 30HP load the mechanical fan it replaced put on. On that vehicle, switching from the mechanical fan to the electric fan was worth 2MPG and boosted top end power like it had a supercharger added, which indicates that the mechanical fan was sucking a lot of juice from the engine to beat air to death.

    But I digress. If they are seeing a 4 percent increase in fuel economy by going from a full time alternator to a part time alternator, then we can expect to see as much as an 8 percent increase by going to no alternator. Annnd, if we (and I mean those of us on this board) can come up with a way to use a bunch of these automotive heat source power producers in a stationary environment, then we might be able to come up with a wood powered house as a boost/backup to a solar powered system.

    I'm pretty stoked about this.
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    Well let us know when there is a product to buy, so far no links to anything but "research".
  • Brock
    Brock Solar Expert Posts: 639 ✭✭✭✭
    Re: "New" Technology Charges Batteries using Heat

    When I was running without my alternator I saw about a 3-5 mpg improvement. I went from about 56 mpg to 60 mpg over 4 tanks, it's always hard to tell what else might influence mpg though, but it dropped about the same when I switched back to using it. As others had pointed out if I had actually removed the pulley and alt it probably would have saved a bit more, but of course it is a serpentine belt around everything and I didn't want to mess with it.

    I actually had a pelter from an old 12v cooler and stuck it to my stove. It already had fins on the "cold" side and it generated about 300 mA when directly connected to a 12v battery. I used it for about a week until it just stopped working. I am guessing I cooked it when the stove was really hot. I was pretty proportional as it got hotter it made more power, then sort of leveled off when the stove was about 350F (exterior) or above. It was neat, but I can imagine something that can tolerate temps from 80F to 600F has to be pretty durable.
    3kw solar PV, 4 LiFePO4 100a, xw 6048, Honda eu2000i, iota DLS-54-13, Tesla 3, Leaf, Volt, 4 ton horizontal geothermal, grid tied - Green Bay, WI