Welcome to the Energy Blog

  • The Energy Blog is where all topics relating to The Energy Revolution are presented. Increasingly, expensive oil, coal and global warming are causing an energy revolution by requiring fossil fuels to be supplemented by alternative energy sources and by requiring changes in lifestyle. Please contact me with your comments and questions. Further Information about me can be found HERE.



After Gutenberg

Clean Break

The Oil Drum


Blog powered by Typepad

« Why Not Plug-in Hybrids Now? | Main | Are Ethanol Pipelines a Good Idea? »

June 05, 2007



Symko states an initial efficiency of 20-25% heat to energy.


The military application is aircraft radar and there is a commercial application in development for harnessing waste heat:


Green Assassin Brigade

Here's a link about the same technology being used to convert wood stoves into refridgeration units and recharging stations for Bangledeshi peasants.


The articles never specify how much heat is needed to create the vibrations.

A blow torch is hotter than most industrial waste heat, what is the temp requirement of these techs?


The following suggest the temperature delta must be greater than 90 degrees fahrenheit.


I've yet to see any discussion on what the thermodynamic limit is for conversion efficiency of heat to sound.



The theoretical upper limit of conversion efficiency of heat to sound is the same as it is for conversion of heat to mechanical or electrical power:

Efficiency = (T hot - T cold)/T hot

There must be a heat source and a heat sink for conversion to take place. These are the T hot and T cold. Note that the temperatures are absolute temperatures (kelvins or degree Rankin).

To get kelvins, add 273 to °C. To get degrees Rankin, add 460 to °F.

So given a room temperature of 70°F (530°R) and a heat source 90° hotter at 160°F (620°R), the maximum amount of heat that could be turned into sound (mechanical energy, electrical energy) is (620 - 530)/620 = .145

That is, at most 14.5% of the heat could be converted. The other 85.5% of the heat is still heat exiting into the 70°F ambient.

In the real world, conversion efficiencies are always lower.

Thomas Marihart

Thermoacoustics is not new.

LLNL and Sandia have been each tinkering with the concept...but mainly for cooling and GTL applications.

The problem with combining thermoacoustics and piezoelectronic power generation is scale.

It may work driving small voltages, but getting it to produce the power levels needed for anything beyond consumer/small devices might prove problematic.


Interesting idea. But one thing this story doesn't address is noise. I realize the point of the piezoelectric unit is to capture the sound waves, and therefore eliminate as much noise as possible. But isn't "leakage" inevitable? And if so, do you really want a noise generator to cool your computer or military-radar system?


Turning heat into electricity, especially from relatively small temperature differences, sounds worth pursuing but doing so cost effectively seems to be an ongoing problem. 90F degrees difference is still large and a lot of energy will go to waste. Using waste heat makes sense but we should be using those simple forms much more - heating water, heating and cooling buildings. Design, incorporating energy efficiency from the ground up could yield greater gains than thermo-acoustics.


Does anyone want to offer details of what they think a system using solar energy as the energy source would look like with this technology. Thanks

Michael Crumpton

"90F degrees difference is still large"

I don't know what you are comparing that to, but power generation stirling engines typically use a temp difference of more than 500° F, and the solar towers that use steam turbines are way more than twice that.

This is the perfect energy scavenging tool. the waste heat coming out of a furnace or water heater stack or even a car exhaust pipe is a whole lot hotter than 160° F and when it is cold outside the greater temp difference makes even more energy available.

The big advantage of this tech is that it is cheap to make. A generator consists of a hollow tube with a ceramic grid that absorbs the heat, a moving coil on a diaphragm(like a loudspeaker coil) and a magnet, and that is just about it.

Even the materials are cheap. The tube could be made of almost any material: metal, concrete, conceivably even wood, and there is almost nothing to wear out, no cranks, no bearings, no complicated electronics.

What this tech lacks in efficiency it more than makes up in cheapness, reliability and simplicity, and with time the efficiency will improve.

As far as energy sources are concerned, an 8' parabolic dish can make a focal point hot enough to make a 2x4 burst into flame instantly (1500°+ F). Even if the efficiency of this gadget is only 15%, that is useful power, especially if you can heat your hot water with the 85% of the heat that is not being turned to electricity.


what about the noise pollution?

Green Assassin Brigade

The article I posted on about this use for woodstoves mentioned that if the tubes were rigid enough the noise was limited to a slight hum, The more flex the tubes have the more they transmit the noise outward and away from the coil, creating quite a din and lowering efficiency.

The main article talks about rings(donuts) as one option where the noise does not reflect back from flat ends but continues around for mutltiple passes of the coil.

Without rigidity and insulation they apparently create well over 100 db.

Doug W


Just imagine coupling this technology with Sterling Energy System's parabolic dish setups or a parabolic trough that heats a fluid.


Michael, I still think 90F is large, even if most heat engines use higher, but Stirling engines can and do run at lower differences, (according to Wikipedia, as low as 14F degrees), perhaps with lower efficiency. When it comes to waste heat, lots of it is less than 90F above ambient. Above that, if it's going to waste, it truly is wasteful. Still, if thermo-acoustics can find applications, or be significantly improved, thats only positive. In the meantime there is a lot of waste heat that doesn't need advanced technology to be put to use.

Michael Crumpton

Some Stirling engines can run at even less than 6° F, but these engines have outputs in the low milliwatt (1000th of a watt) range, so they are essentially toys, or physics demonstrators. The problem with extracting energy from low temp differential sources is that there is not a lot of power there, or the power is so diffused that the mechanism to harvest it needs to be huge.

For a 90° temperature differential generator to be cost effective you would need a lake of it, and a cheap (non energy consuming) way to move it quickly past your engine.


Los Alamos has been working on this technology for several years. http://www.lanl.gov/mst/engine/
Ben and Jerry's ice cream also did a thermoacoustic refrigeration demonstration several years back.
I'm hoping that Symko isn't trying to take credit for "knovel" idea when it's already been reasonably well developed. Hopefully he finds a good application for an interesting physical phenomenon.


Online prescription for phentermine
Phentermine overnight shipping
Information phentermine
Phentermine to fla
Phentermine online
Order phentermine without a prescription
Phentermine 20diet 20pill
Lowest price phentermine
Information on phentermine
Buying phentermine with mastercard
Phentermine cheapest
Phentermine with no prescription
Phentermine blue white specs
Where can i buy phentermine online
Where can i purchase phentermine online
The phentermine
Phentermine no rx needed
Buy phentermine without a credit card
Cheap no perscription phentermine
Adipex phentermine xenical
Where can i buy phentermine without a prescription
Phentermine vs meridia
375 phentermine
Phentermine online no prior prescription
Phentermine fedex
.mg phentermine
Phentermine phentermine
Little phentermine
Prescription free phentermine
Phentermine addiction
Phentermine lowest prices
Phentermine 30mg yellow
Phentermine direct
Phentermine xenical diet pill
Addiction to phentermine
37.5 phentermine
Does phentermine really work
Buy discount phentermine
Phentermine 37 5
Phentermine offshore
Phentermine consultation
Adipex phentermine vs
Phentermine order
30mg phentermine
Phentermine discount
Compare meridia and phentermine
Phentermine forum
Phentermine online without prescription
Phentermine 37 5
Online consultation for phentermine
Lipodrene phentermine
Cheapest phentermine compare prices
Is phentermine safe
"order phentermine"
Generic phentermine
Effects of phentermine
Real phentermine
Phentermine for weight loss
Phentermine online order
Phentermine yellow a160 imprint
Phentermine hrt
Phentermine sales
Phentermine no prior prescription usa next day delivery
Phentermine rx
Buy phentermine without perscription
Phentermine free consult
Best phentermine pharmacies
Phentermine weight loss
Envy phentermine
Phentermine addiction
Canada phentermine
Phentermine testimonials
Diet no phentermine pill prescription
Phentermine 15 mg
By phentermine
Phentermine sales
Phentermine rx
Phentermine phentermine
Buy phentermine epharmacist
Phentermine weight loss result
Do you know how i can buy phentermine
Diet no phentermine pill prescription
Prescription phentermine overnight
Phentermine more drug side effects
Phentermine 37.5 mg
Cheap no prescription phentermine
Phentermine para bajar de peso
Phentermine phentramin
Phentermine info
Fioricet phentermine westword
Cheap 30 mg phentermine free shipping
Buy phentermine adipex
Information on phentermine
Phentermine 37.5mg 90
Phentermine 37.5 without membership and doctor
Drug phentermine
Phentermine worldwice
Phentermine online us pharmacy
Phentermine dangerous
Topamax and phentermine
Phentermine without md prescription
Buy cheap phentermine
Phentermine sale
Phentermine online no prescription

Phentermine diet pills
Phentermine c.o.d
Phentermine vs adipex
Cheap phentermine no prescription needed
Phentermine buy online in stock
Diet pills phentermine
Do you know how i can buy phentermine
Phentermine for weigh loss
Dangers of phentermine
Phentermine diet pillscom
Buy cheap phentermine under 75 without rx
Phentermine blogs
Cheapest phentermine without prescription
Online phentermine prescription
Phentermine ingredient
Phentermine on sale
Phentermine 37.5 mg.
Phentermine online cheap
Compare meridia and phentermine
Cheap 37.5 phentermine
Pictures of phentermine
Buy cheap phentermine with dr. prescription
The phentermine
Prescription phentermine americian express
Phentermine 375mg tab
Phentermine us
37.5 89 cheap phentermine
Phentermine 37.5 free shipping
Phentermine weight loss pill
Phentermine addiction
Phentermine order online
Diet pills phentermine
Herbal phentermine
Phentermine 375mg
Phentermine no rx required
Phentermine 375mg tabs
Get cheap phentermine without a prescription
Phentermine without prescripton
Order phentermine 37.5
Phentermine forum
Pictures of phentermine
Buy cheap phentermine
Cheap phentermine
Phentermine at discount prices
Phentermine lowest price
Cheap 37.5 phentermine
Phentermine 37.5 no rx needed $165
Phentermine reviews
Phentermine in kentucky
Phentermine on sale
Cheap overnight phentermine



Buy Propecia

Thank you very much for the information I really appreciate it!!

Online Pharmacy no Prescription

Comments please

generic viagra

lots of comments here, which one is best

Online Pharmacy

Devices that convert heat to sound and then to electricity lack moving parts, so such devices will require little maintenance and last a long time.

us drugstore

Thanks, helpful source.

Buy Viagra

Great site, I am bookmarking it!Keep it up!
With the best regards!

Chronic Pain

, Hi I want to share this information, I think is very important for you: Acute pain is fairly subjective in nature and the level to which it is felt depends on the specific person feeling it. Some people are capable of tolerating more pain than others while there are some who cannot even tolerate the slightest amount of pain.

Rare Disorders

Let me tell you people the European Council Recommendation on Rare Disorders adopted
EURORDIS welcomes the final adoption by the European Council on June 9th, 2009, of the proposed Council Recommendation on European Action in the field of Rare Diseases. The Council Recommendation represents an important milestone for rare disease patients all over Europe.


Hello It's important to realize these food substances were identified (documented) by the likes of Pliny and Dioscordes (ancient Greeks) first century AD and later by Paul of Aegina from the seventh century. Aphrodisiac

Viagra Online

I can't believe that they do it in only one week.

ED treatments

Im Robert and I 60 yaers old and let me tell for me
ED treatments was the best thing that could have created

Generic Viagra

I'm 47, I had noticed since my late 30's that my erections were not as hard and it was taking longer and longer rest periods between sex before I could archive and keep an erection.


dirty hands,contaminated food or water,
some pets,direct contact with fecal matter
major carriers of germs and cause infections

Buy Viagra

hey I like this blog! you have did an excellent job with this post!!
Marianna J. Turner

Generic Viagra

This invention is incredible! are fully confident in your product or even research being done? But I think it's wonderful.

forex trading system

I like your blogging style, very original, apart is very interesting and I would like learn more.



I'm going to try this for my science project, is very interesting.

Top Affiliate Programs

I'm really impressed with this discovery. I am a scientist by nature but I do not have the financial resources to pay for a college. Actually I do is read on the Internet all the discoveries and findings to publish


Just one question. Who can attend these meetings, only members of an organization and the students?Health Care

Wet Lubricant

Thanks for this helpful information.

Womens Health

Thermoelectric materials have long held the promise of being able to harvest waste heat and turn it into electrical energy. Although useful in applications other than energy generation, thermoelectrics have long suffered from poor efficiency,

natural Viagra

Interesting information, added your blog to my favorites.

us drugstore

This is some very valueable information, thank you very much.

Safe Diet Pills

Diet pills can be an effective way to achieve quick weight loss when you choose wisely and pair them with a healthy diet and daily exercise.

generic viagra

"We are converting waste heat to electricity in an efficient, simple way by using sound"

Buy  Cialis

As with audio, you can convert the heat?

Acquisto Viagra

You have a very good blog that the main thing a lot of interesting and useful!

online pharmacy no prescription

Thanks for posting this very genuinely interesting post. Keep up. Will be back to check out again.

xbox купить

Great to see a collection of blog posts that includes thoughtful and perceptive commentary. Keep up the great work!

Invertir Dinero

Great site about A Sound Way to Turn Heat into Electricity ,this information really helped me , I really appreciate it,I will visit when ever i have found the stuff That i have been searching for in all the web for, keep up the great work!

generic cialis

Symko and his students are developing much smaller devices that not only convert heat to sound, but then use the sound to generate electricity.

Order Viagra

The best on the blog interesting.Thanks!

phentermine 37.5 without prescription

I like the foundation of this blog has a great variety of comments really appreciate it.

The comments to this entry are closed.

. .

Batteries/Hybrid Vehicles