It is amazing to me that the mods have not reprimanded the thread starter yet. In most of his posts he brings up both politics and religion(Bible quotes). Where others have been dealt with for less open infractions. Nothing against his questions on other subjects but let's at least treat ALL members the same when it comes to the TOS.

 

There is a lot of wasted energy generated right here on AAC.
There's got to be a way to harness the energy from all this hot air.

Jewels of wisdom to Joules? -- I like it

 

Roland, you are among a lot of knowledgeable people here on AAC who are willing to teach you simple and complicated things if you care to listen.
Sometimes it is advantageous as well as refreshing to approach a subject matter from the beginning with a fresh and unadulterated mind. However, 99% of the time, well established scientific principles rule the day.

Ask a simple question and you will get many simple as well as complex answers, usually with good intentions.
Then you need to read the answers, learn from them and move on.

 

Capturing waste energy is like picking the rotten fruit off the ground after the low hanging fruit have been picked.

It is well known that mining companies will reprocess mine tailings when extraction processes improve over the years and therefore allow companies to economically recover additional minerals from tailings.

Same thing with energy systems. The primary extraction of energy from the source is sufficiently cost effective that makes secondary extraction not economical.

Our primary source of energy is from our star, the sun.

 

About half the commenters here are as much at fault on the negative side as the OP is on the positive side in terms of evaluating the usefulness of capturing waste energy.

Look at the compound steam engine; the secondary and additional stages do exactly what the OP is suggesting, and do it quite successfully.

But the naysayers are correct on one point, to be practical, you have to put the effort in to work out the numbers. If you don't do that, you are doing nothing but dreaming, and while there's nothing wrong with dreaming, it shouldn't be confused with engineering.

 

or you can be an engineer dreaming:

 

About half the commenters here are as much at fault on the negative side as the OP is on the positive side in terms of evaluating the usefulness of capturing waste energy.

Look at the compound steam engine; the secondary and additional stages do exactly what the OP is suggesting, and do it quite successfully.

But the naysayers are correct on one point, to be practical, you have to put the effort in to work out the numbers. If you don't do that, you are doing nothing but dreaming, and while there's nothing wrong with dreaming, it shouldn't be confused with engineering.

I agree.

Most power plants just dump their waste heat into the air or into a body of water. But you CAN recover useful energy from it -- it just may not be cost effective to do so. And there is a limit on how much useful energy you can recover. Coors used to dump their waste heat into Clear Creek, but because they are strong supporters of the Colorado School of Mines, they ran a steam pipeline up to the school and use the school's buildings as one of their waste heat dumping points, which drastically reduces the school's heating bills in the winter, but doesn't help out Coors too much during the summer.

I have often envisioned a power plant that dumps its emissions into a huge enclosed area that is filled with fast-growing trees or other suitable vegetation to sequester some significant portion of the CO2. I envision that vegetation being harvested on a continual basis to keep the system in balance. Maybe that vegetation can be used for food or for building wood or for crafts or even if it used for firewood that is still beneficial since the CO2 got used twice before being released with the second time being as a vehicle for solar energy. Taken to its extreme you could imagine a wood-burning power plant that is surrounding by a huge enclosed forest that supplies the wood for the plant.

But while all of this is great sounding on paper and would be fine in a science fiction novel, that hardly makes it feasible in practice and does NOT constitute any kind of science or engineering. That would require analyzing the system and cranking the numbers, using very simplified models at first and then better models if the results of the coarse analysis looked promising.

 

Auto exhaust gas is what, 100 degrees above ambient?

Try about 5 - 10 times that. All most half your fuels thermal energy can leave through the exhaust under certain driving and engine load conditions which is plenty to run most any TEG system. The problem is manufacturing costs. Automotive manufactures could care less about stuff like that being it would cost them far more to make than what it costs to make and put an alternator system on an engine.

Although I'm not an automotive engineer it is my understanding that fully 2/3 of the energy derived via combustion is lost to (i.e. dissipated by) the exhaust and cooling systems with a rather small fraction of the remaining third ultimately applied to motion of the vehicle aye! aye! aye!

Maybe in the old days a well designed automotive IC spark ignition engine could in rare cases hit ~33% efficiency but given modern emissions designs we are lucky to see half that fuel energy being turned into mechanical energy in the average vehicle.

I have often envisioned a power plant that dumps its emissions into a huge enclosed area that is filled with fast-growing trees or other suitable vegetation to sequester some significant portion of the CO2. I envision that vegetation being harvested on a continual basis to keep the system in balance. Maybe that vegetation can be used for food or for building wood or for crafts or even if it used for firewood that is still beneficial since the CO2 got used twice before being released with the second time being as a vehicle for solar energy. T

What if we made the containment system huge. Like planetary huge and we just lest anything and everything that uses CO2 as part of biological process have a go that whatever it can collect and we just harvest what we want from that?

No wait... That wont work. It wouldn't cost anything and no one person or corporate entity can claim sole rights to the process and make a profit off of it then.

 

Maybe in the old days a well designed automotive IC spark ignition engine could in rare cases hit ~33% efficiency but given modern emissions designs we are lucky to see half that fuel energy being turned into mechanical energy in the average vehicle.

Yet modern engines are putting out considerably more power and getting considerably better fuel economy than comparably sized vehicles from a few decades ago.

Now, I definitely agree that when we just tacked on a bunch of emissions controls it had the effect you describe. When I took off the emissions stuff on my old '75 Bronco as part of an engine overhaul that also made a bunch of changes (10:1 compression, RV-1 cam, high-rise manifold, 550 cfm 4-bbl spreadbore carb, tuned headers) my power went up considerably but my fuel economy went up 50% (from 10mpg to 15mpg) and my emissions actually improved significantly because, among other things, now the engine could breath. Before the rebuild I was blowing something like 6% CO (was allowed 8%) and about 600ppm HC (was allowed 800ppm). After the rebuild I was blowing about 2% CO and 300ppm. Eventually I was required to put catalytic converters (and I had to put two of them on since I now had dual exhausts) and an air pump on it. Those didn't cost me too much in mileage (was about 14mpg afterwards) or power and I have to admit that they did significantly improve the CO and HC emissions -- I was down at 0.1% CO and 13ppm HC. But I don't want to even think about what my NOx emissions must have been given the temperatures that thing was running at.

 

yes, modern designs put out more power than some older ones, but that was by design. how long did the car mfgrs use cast iron over head valve engines with poorly designed intake and exhaust systems truning out less than one hp per cubic inch? while at the same time dual overhead cam aluminum engined with more power were being made in europe and japan with more power?
ad as for 100 degrees above ambient exhaust temps, there were s lot of fire trucks and pickups burnt to the ground here in kansas because the catalytic converter was so hot it lit the grass and weeds on fire.

 

There may be a disconnect in talking about exhaust gas temperatures. The EGT at the valves (beginning of the exhaust train) is generally a LOT higher than the exhaust at the end of the tailpipe. So we need to keep in mind that different people might be talking about temperatures at different points in the train. If you are going to try to extract energy from the exhaust, it is generally best done as close to the beginning of the train as possible.

 

even power plants have added energy recovery systems to their plants. do we all have to wait for someone to come up with an extremely expensive new car to get more efficiency? can nothing be done to recover waste heat from cars that already exist, while waiting for blue sky ideas that nobody is trying?

If nothing else it seems to me that we could send trickle charges into rechargable batteries in order to power radios and led flashlights or whatever requires a battery on a small scale. Some of us work very hard for a living and never see more than a few dollars and some change after we're done paying the bills each month, on top of paying the surprise bills when something is needed much like the septic tank problem I recently had to place on a credit card. Every little bit of conserved energy is useful somehow. Just like taxes. Even one added cent to the gasoline tax amounts to one heck of a lot when most of us are dependent on the fuel in order to get to and from work. But more often than not it seems that predominantly we (generally speaking) are a very wasteful society with a throw away mentality. So what does anyone care about a trickle charge for example these days? When you are struggling like heck to make due working damn hard those millivolts can make a person salivate about as quickly as Pavlov's dogs when the bell rings.

 

Do an ROC (return on capital) calculation for your trickle chargers using realistic values. Let us know how that compares to buying from the power company.

John

 

If nothing else it seems to me that we could send trickle charges into rechargable batteries in order to power radios and led flashlights or whatever requires a battery on a small scale. Some of us work very hard for a living and never see more than a few dollars and some change after we're done paying the bills each month, on top of paying the surprise bills when something is needed much like the septic tank problem I recently had to place on a credit card. Every little bit of conserved energy is useful somehow. Just like taxes

I just don't see the point of collecting nits (micro and pico watts) worth or power when there are other far more practical and larger waste energy sources that can produce watts to be had just as easily and cheaply. Its like collecting micro fractions of a cent expecting it to it to add up to something useful some day while ignoring the quarters and dollar bills laying around on the sidewalk.

Just do the math on how long it would take to recharge a small 1.2V 900Mah AA rechargeable battery when you have a few tens of microwatts (millionths of a watt) to work with. That's the realistic problem here that keeps being ignored by you. True usable value of energy to be captured in what time scale.

Do you have 100,000+ hours of free time available to wait for a single 1 watt battery to charge up off of lost antenna power?

Personally now that I am laid off and the weather is warming up I too plan to start working on my energy harvesting projects again as well. The only difference is I am working with wind power which can easily and reliably produce several hundred watts and more with minimal investment on my part which is a power level that can be used to do something practical. Might even dig out the TEC devices again and play with them some more too.

 

thermocouple units for running transistor radios were described back in the 60's for use in third world countries that used candles or anything else that would burn actually on the market. evven some satelites are powered by thermo units, radioactive decay provides the heat. for probes that are too far from the sun to use solar cells.

 

One of the "circuits" that springs into my mind is "harvesting free energy" using a wire wound on a 230v line. It can be enough to light a LED.

Or run it through a ferrite and make a secondary winding.
As it is inlined, not accross L and N, no energy is consumed and the obtained energy is free.

One answer is compared to the Gigawatts produced by power stations, the microwatts or few mW are totally insignificant.

Another ehm well uhmm...circuit...

Charge a 220nF capacitor with a 9v battery and discharge it with a LED. You can observe a flash!

Some day, it will be attempted to take old batteries from shops recycle containers, plug them all into a giant Joule Thief converter in the trunk of a small electric car- one hour later, drive away using that free energy.

Something weird- I had a couple of JT circuits, the batteries almost drained.
Then there was a thunderstorm, not happening very often here in Ireland.
An hour before that, the JT with large MONO cell awoke to new life!

Yes. It really happened.

Make a flying carpet with large MONO cells, and let it float just an hour before a thunderstorm.
Gigawatts! Only a few problems:

-How to know when there is a thunderstorm
-How to move the flying carpet base station + lift it very fast
-How to "extract" the electrons from the MONO cells

But for sure some genius will solve all these problems.

 

As it is inlined, not across L and N, no energy is consumed and the obtained energy is free.

Is it just me, or...

 

One of the "circuits" that springs into my mind is "harvesting free energy" using a wire wound on a 230v line. It can be enough to light a LED.

Or run it through a ferrite and make a secondary winding.
As it is inlined, not accross L and N, no energy is consumed and the obtained energy is free.

You would, I believe, benefit from a study of mutual inductance...

With constructive intent
HP

 

As it is inlined, not across L and N, no energy is consumed and the obtained energy is free.

Guess what, you just created a transformer. The energy extracted does not go unnoticed.

 

Guess what, you just created a transformer...

Indeed he/she did! --- An air (or, alternatively, ferrite) core Xfmr operating at ELF!? --- A 'Joule thief' indeed but with a rather light touch! ;-)