Stirling Engine based hybrid car

I'm not the only one to have thought of this, but as yet no real work has been done. How about a hybrid car powered with a Stirling Engine? (Not spelled Sterling, btw.)

The Stirling is more efficient than the internal combustion or diesel engine, and it's also a lot quieter. Sounds great, but it's not good for cars because it can't rev up quickly and it takes about 5 minutes to get the engine hot enough to run well. We want our cars to start the minute we put the key in.

A hybrid design (with enough batteries for 10-20 miles) solves this. You can get all the acceleration you need from the electric motors, and you can start driving right away, while heating up the Stirling "boiler". Then it kicks in to provide the power to run the car for the long haul. If you know the trip is short, no need to fire up the Stirling until the battery gets low.

The Stirling can burn anything. Gasoline, kerosene, diesel, vegetable oil, hydrogen, even wood! Yes, you could, in theory, be stuck by the side of the road out of gas, then go out with an axe to chop trees and refuel your car.

Well, almost. You want high-temperature burning for the best efficiency, and this would pollute and probably dirty your nice clean boiler. Right now the engines are expensive to machine but I suspect that could change.


This occurred to me as well, but there are very good reasons why automotive Stirling engines are still a fair way off. They are significantly larger than internal combustion engines for the same output because the working fluid is separate both from the combustion gas and from the atmosphere. They require huge radiators and lots of air blowing through the radiators to get the kinds of efficiencies they boast. People like roomy cars, not cars that devote half their space to the engine and its associated bits. Large, efficient radiators (not to mention regnerators and other sorts of heat-exchange doohickeys that would be used on automotive Stirling engines) also tend to be expensive, not to mention heavy.

Ultimately, there is no particular reason to believe that, even given large amounts of development work (time, money), a Stirling-powered hybrid would be any more efficient or even cleaner or quieter than even current hybrids or even a plain old Honda Civic. Plus, hybrid diesels are on the horizon, which will give an additional 30% efficiency boost on top of the already impressive numbers from current hybrids, while being cleaner than current gasoline engines. The hybrid design eliminates most complaints about diesel engines at least as well as it eliminates (some) complaints about Stirling engines.

Keep in mind that the Prius also isn't your grandpa's Otto cycle. It uses a Miller cycle engine, which allows it to run on beer. Err, actually, it gets rid of the need for a throttle plate by using intake valve timing to control load on the engine, thus eliminating losses due to sucking a vaccuum. Unfortunately, this has a drawback on regular cars - no low end torque. This is why the Mazda MX6 that used a Miller cycle engine was supercharged, which kind of gets rid of some of the efficiency advantages. A hybrid like the Prius (and now the Ford Escape) can bypass this problem altogether. Sound familiar?

IMHO, the engine that the hybrid design, especially series hybrids, fits the best with is the turbine engine. Turbines like to run at constant speed; their acceleration characteristics are even worse than Stirling engines. They are the most compact engines for a given output, at least for higher output (>50 hp or so), and their ability to scale down to even smaller outputs and higher power densities is improving evey day due to the use of microturbines in industrial applications. They have the same "run on any fuel" characteristic as external combustion engines such as the Stirling engine, though diesels actually also have this characteristic.

In conclusion, don't be so quick to throw out internal combustion! Otto and his cousins have a lot of years left in them, and I expect we'll be driving around in internal combustion-powered cars right up until flywheel-powered electric cars put them out of business. That is, assuming the energy policy people get their act together and either get out of the way or quit kowtowing to the eco-nazis who are preventing us from using one of the greenest electricity sources of all: nuclear power. If not, well, I guess we'll be driving around with good ol' Otto well into the next century.

BTW, boilers are steam engine parts. The part of the Stirling engine that you're talking about is the combustion chamber, and there is no particular reason it needs time to heat up. Even steam engines can be made to come to temperature quite quickly.

Nuclear Power - Greenest - I think not...

When assessing the costs ($, environmental & opportunity etc.) you need to look at the full lifecycle, and at everything that is affected by it.

In the case of nuclear power - the people who keep insisting we look at it consistently omit the massive decommissioning costs (which far outwiegh the initial commissioning costs). We also need to look at the human costs, which thus far are consistently covered up and avoided (how many americans have factor V leiden mutation?, how many children have lukaemia? how many people have lost their jobs and their reputations for asking these questions?).

Not to mention the increased chances of some terrorist getting hold of some weapons grade plutonium...

The reason they keep pushing for it is probably because they own stock in the construction companies (eg Haliburton) that would win the contracts...

Why make power when it's already there? We should be harnessing the solar, wind and wave power that is there already. Cars could easily run on biomass, eg. Wood alcohol (renewable and truly clean).

We could also massively reduce our energy needs without compromising our modern lifestyle. The average house could reduce it's power consumption to a fifth if we just switched to energy saving technologies and were properly insulated.

Your argument is petty, nuclear power is the cleanest we have at the moment. There is less radioactive poisoning in the cooling water that is released into the environment then there is in a pint of beer! If you want to bring in arguments about ecological impacts then lets talk fossil fueled power plants, more specifically, coal. Coal plants generate in excess of 40 million tons of mercury and 13.6 times the radioactive fallout of a nuclear plant.
simply put, there is no substance that can fuel a candle hot enough to nuclear power-nothing!

Dont be too happy about nuclear power. The waste problem is unresolved, the bomb proliferation problem seems to press america into a new war, and the amount of uranium lasts for no more than 60 years.
40 million tons of mercury look quite a little much to me for coal driven power plants, especuially if the exhaust is filtered. Did there someone do a calculation with a point error?
Radiocative fallout: If the neandertal men would have used the atomic power in our way, we would have no uranium left, but still sit on the nuclear waste.
May be that there is a lot of C14 coming out of a coal power plant.
But all of the plutonium in the sea is made by nuclear power plants.
And this is not a little amount! And a very strong poison.
So your last sentence is rubbish.

If you would indulge in reading the report "Coal Combustion: Nuclear Resource or Danger" by Alex Gabbard(, you will see from the conclusions that coal power releases five times as much radiation as the least regulated reactor, which is calculated to be one hundred times the population dose equivalent of nuclear power. Essentially, this is due to the fact that coal is an impure fuel that contains between one and ten parts per billion of uranium (and 2.5 times as much thorium). This is then released directly into the atmosphere (scrubbers are not required by federal regulations for these exotic metals) or accumulates in piles of fly ash (generally glass beads) that are distributed through water runoff, airborne contamination, and the food chain. Very startling, so see the results for yourself.

Nuclear energy is about Chemistry, as in putting two or more substances together in a way that make energy that people can use. The nuclear plants that the U.S. has are largely an offshoot of the weapons development program from WWII.
There are other ways to use uranium and other radioactive elements to create electricity which can be less dangerous or waste-producing if they were developed with the same vigor as weapons grade stuff. Most ideas stays on the blackboard because the nuclear age literally started with a bang and the fear factor among much of those inexperienced in nuclear chemistry is high. Canada has an active plant now that uses straight out-of-the-ground uranium and Deuterium Oxide (Sometimes Called "Heavy Water") to make heat to run Turbines. This is actually one of the earliest, Pre-KaBoom designs. Uranium decays to lead eventually. One that I hope is being developed re-uses the present waste until it is inert.

Are the first mistake you main was in the first sentence, do you actually know what nuclear energy is and how it works.

Number 1: nuclear energy is Physics not chemistry.

Number 2: nuclear energy is not a chemical reaction with reactants. It is a process that involves high energy particles such as beta particles, alpha particles or neutrons colliding and splitting the nucleus of an atom, resulting in a loss of mass which using the equation by Einstein E=mc^2 gives you the amount of energy produced. It is in no way a process that involves substance in instead involves fuel rods that are usually uranium which will undergo a controllable nuclear reaction to for smaller radioactive elements.

Number 3: Yes you are correct there is a cleaner and better for of nuclear energy, it is called fusion. Problem is that it is hast actually been successfully done yet for a long duration or produce a usable power output. and this is not from a lack of trying. it is a far more complicated process. Look up the refit and current use of the Z machine and you will know what I mean.

Nuclear Power is not as clean as solar photovoltaic cells, nor wind energy, considering the whole process and risks involved. Look at all aspects. There's the mining matter - it requires enormous mines to get the Uranium from low-grade ores, with all the associated risks and energy useage at that step. Then onto getting the miniscule amounts of fissionable Uranium from the Uranium Yellowcake. Then the fabrication of fuel pellets, use, and when done, all the radioactive parts of the plant that need replacement & go bad from metal embrittlement, in addition to the hot waste. Cooling water smoolng water! Never mind that! I agree - Coal is worse at present; but Brad's right when he says energy conservation will get us a five-fold increase in efficiency, with greater comfort levels! I've done this - taken one home and reduced it's energy demands to 1/5 th the original levels, and it's comfy! Fresh air with heat exchanger to boot! And there's room for even greater improvement - it could use more attic insulation and some solar hot water panels (which pay back in a few short years); perhaps taking less than a 10th of the original energy load when all is completed.
Now, let's look at solar cells, fer instance. The most common ones are made from Silicon, of which the supply is everywhere and virtually limitless. The industrial process runs some risks, true enough, but these risks are minimized in-plant risks, and there is no lasting radioactive waste to deal with. Once produced, silicon solar cells have, at a minimum, a 20-year life expectancy; probably more than 30 years in reality. The only things that really go bad on them are the coatings (i.e. PolyVinyl Acetate) that degrade, contact corrosion from condensation, and connections that come apart after decades from all the contration and expansion via day/night temp. swings. They pay back for the energy inputs is roughly 5 years (give or take the climate), and they are silent and very reliable. Power needs to be banked, but newer storage mediums can help there as well. (Nanotube ultracapacitors, Flywheels, etc.)
Simply put, it's not super-powerful Uranium that we need, but rather applied common sense. All we really want is cold beer and hot pizza! :>

nuclear power is a very long-duration project. when one considers the resources and power required to keep nuclear power plants in good condition and to keep nuclear wastes in safe storage, one can easily see that there is little energy gained from investing in a nuclear power plant.

other alternative power sources, like wind power, wave power, etc will theoretically have big impacts on the climate if used in large numbers. when people use turbines or other machinery to take energy out of wind, for example, the wind is slowed down because the energy was taken from it to move the electrons. consider, then, what would happen if alot of energy was taken from the wind. it may slow down so much that current weather cycles may be no more. perhaps cloud formations wouldn't move where they were supposed to go, and one place flooded while the other experienced droughts. certainly not good.

the thing is, we simply need to conserve our resources and take as little as possible

Take energy out of the wind? Wow. Actually, if we want to talk green here, there used to be far more "wind-dampers" than there are now - they were called "Trees". Unfortunately, the energy they took from the wind was wasted in the form of heat as the wood fibers expanded and contracted as the tree and it's branches and leaves were flexed by the very abundant wind. The cool thing about wind is that it is renewable (should be BLATENTLY obvious, but at this point I'm taking no chances), and as long as there are temperature differences in the atmosphere (ie., as long as the sun shines and is absorbed differently by different substances - you know, like continental crust and ocean water), we will have wind. And as we are currently experiencing the environmental impact of the REMOVAL of these pre-existing wind-dampers, I sincerely doubt there is a legitimate issue with putting a few BACK - lol!!

Can someone explain to me why a solar plant covering acres and acres of land, is environmentally friendly? What about the plant life and animals that will be displaced due to the lack of sun and heat?

Can I put solar on my roof? SUre, but I will never have enough energy to run my A/C...and to store power for the night I need probably a ton of batteries...taking up room not only on my property but on landfills when I am done with the.

And as far as wind energy goes...what do you think happens to the environment when the wind is STOPPED at a certain point? Can you imagine the problem the birds will have in migrating? What about the changes in the weather due to unnatural high pressure and low pressure areas.

The ONLY reason nuclear is expensive is due to EXCESSIVE regulation. Believe me, I would rather have a NUCLEAR REACTOR next to my home, rather then a WIND TURBINE, SOLAR FARM, OIL or COAL BURNING plant ANYDAY. In fact, I WOULD PAY for a NUCLEAR SUB/AIRCRAFT CARRIER generator for use in my town.

Can you imagine the problem the birds will have in migrating? What about the changes in the weather due to unnatural high pressure and low pressure areas.

ANY bird that is too stupid to fly around a windmill deserves to be extinct

Why store power from solar cells in a battery.
It seems that storing it as hydrogen and oxygen for fuel would be better.

Hello Bill!
Hydrogen's good - zeolite storage may be the most green for H2 and O2. U might want to look at nanotube supercapacitors and flywheels as well. There's a lot of better ways than heavy metal batteries, that's for sure!! :>

Creating hydrogen from water is only about 60% efficient, and then converting it back to energy is again about 60% efficient, resulting in you only getting out around 1/4 to 1/3 of the energy you put into your hydrogen 'battery'. Chemical batteries have efficiencies around 90%, and ultracapacitors have efficiencies of very nearly 100%. In truth, hydrogen is a very POOR energy storage medium. The only reason that it has been touted as a fuel is that a car using it could be refilled at a station much like conventional gas or (more closely) natural gas/propane.

There is another issue here too, electrolysis and/or fuel cells produces DC current. Most components in the US use AC so you will have to rectify or (worse) burn the hydrogen to get your AC. It just doesn't make sense in most cases. Now you develop a case where you can use DC on site you may have a point. I have thought about this in the past and the most reasonable idea I can think of is Sever Farms (huge demand for DC in localized area).

Nuclear on the other hand is here now, works, and can provide most of the power needs for entire planet safely. Disagree with that comment, look no further then France.

The biggest hurdle to making nuclear work is dealing with the waste. We do have several options available to use now though; such as deep sea burial, glass pucks, and my favorite, launching it at the sun (fusion wins over fission) :-). Truth be told we Americans are just to damn scared of it.

There is no technological challenge with producing AC from a DC current. DC/AC inverters are widely available, and getting cheaper all the time as magnetics and switching technologies improve and we move to higher switching frequencies. Cheap small inverters are 80% efficient and everywhere. Big ones are 90 or 95% easily.

Once evidence of the improvement of the inverters is the switch to electronically commutated motors (ECM), which run on DC supply, and convert to AC for the motor. With the increased materials costs of copper and steel (for transformers) these high-tech motors are often cheaper than traditional AC induction motors -- the little cooling fan in your computer likely uses this technology (I hope!) ECM cooling fans are often half the price of comperable AC induction fans, and much more efficient.

And there is another advantage in hydrogen-energy density.Instead of a huge bank of batteries(of the present battery technology)who will take an eternity to recharge, the more practical solution for now, and the easiest to make money for Big Oil(sorry, I meant Big Energy)is hydrogen.By no means is this the better way, IMHO.Ultracapacitors look very promising from my point of view(I'm from Eastern Europe, and we have a thing with developing infrastructure)So using the existing power grid looks more duable.

The Question of using nuke power is moot. Not long term sustainable on any scale.
Coal will eventually run out. Wind will not end...ever (don't be silly!)
Block too much wind, get real man. The real answer is the nuke energy we absorb daily from the sun, in the form of infrared light waves which sustain all life on this planet, period!
So the question is how do you harness that energy to maintain our current lifestyle? You know, like at night, or in the winter when its 10* below....
Concentrated solar.
It's not exotic, just un-publicized. If you take a standard bathroom door mirror and cut it into 3 pieces, then use a frame to bend them slightly and focus the suns reflection from the three pieces of mirror at a piece of wood..IT WILL IGNITE!
There is that much energy available in only the limited area of a bathroom door mirror!
So what you say, what can that do to solve our energy needs? it only works when the suns shining.
True enough.
To store the energy you need a battery, no not an electrical battery, a thermal battery. a cistern buried below ground of say 2,000 gallon capacity (size depends on location ie.. latitude/altitude) and filled with stones and oil. (of any type..waste veggie, mineral, used motor oil) You make your solar collector with a parabolic dish or trough and heat the oil up to five hundred degrees circulating it through the cistern until it comes up to temp. (Very quickly)
You then have a high thermal difference between what you need and what you have. Heat exchangers do most of the work you need done (boil water to create steam for a mini turbine, sterilize dishes , run your home heating unit, keep your house water hot, the list is endless, fueled only by imagination ) run a Stirling engine and power an air conditioning unit (yes with heat! it's called an adsorption chiller and if you live in a hot area your local Walmart probably uses one instead of the older style compressor types because they are WAY cheaper to maintain and contain no toxic materials)
I conclude that we do not have an energy problem, what we have is an energy utilization problem in a profit-based society! There simply is no energy market if every town and village collects and stores its own power needs and each homestead can be set up "off grid" in basically any location. All with the luxuries we've become accustomed to.
So now that you know the answer, What will you do with it?

Run Air Conditioning with geotubes providing passive cooling and dehumidification down to ground temperature at 55 degrees if u want it that cold. Much better and cheaper than using electricity to run a/c compressor. Then run solar thermal stirling to produce electricity on roof of passively heated and cooled house. This would provide enough electricity to run everything else you need with the excess for an electric vehicle or electrolysis of water into H2 and O2 for H2 car or hybrid electric and hydrogen.

I agree - giant areas covered with solar panels is not the way to go! Solar rooftops is. The answer is INSULATION and VENTILATION. Think about it! Why gobble up oddles of energy to heat and cool a home, when it's so much cheaper to just insulate, seal, and ventilate properly? I did it, so it can't be all that hard!!
Hey, that's a good point! But, we've got a long ways to go before the wind stops!!
Nuclear regulation is there for a reason. It's a heavy metal, for one thing. Just ask the Uranium miners who are dying of cancer, because years ago, you were just supposed to "suck it up, soldier!" Maybe not the case today, but there's a reason for regulation. It's called the referee. Without one, the game would be pretty damn unfair (some might say, deadly at times). Good outfits need no regulation, but to allow for them to be competitive, there has to be that referee over there on the sidelines. Now, maybe the referee and the rules need checks and balances, as well as revamping to better fit the situation, but that doesn't mean we should throw out the baby with the bathwater.
I agree. Some applications are best fit with nuclear power. Aircraft carriers are one such application. And, for the time being, we're going to need Nuclear to get us through the transitions into the efficient future. But open up to a new way of seeing things. There are solutions that get us there, and they're not that hard to see!

> Can I put solar on my roof? SUre, but I will never have enough energy to run my A/C

Depending on your A/C, yes you can.

> taking up room not only on my property but on landfills when I am done with them.(sic)

Lead-acid batteries are one of the most recyclable things we have on the planet today, and have immense power densities (they use them on boats for a reason). Just because we do not recycle them in any significant quantity doesn't mean that they're unrecyclable.

> what do you think happens to the environment when the wind is STOPPED at a certain point?

Uhh ... nothing? Need I remind you that mankind has harnessed wind power since before we knew how to write?

> What about the changes in the weather due to unnatural high pressure and low pressure areas.

Oh ... you mean ... like the artificial pressure zones that MAJOR CITIES produce, what with all that massive coating of BLACK TOP all over the place? And highly solar-reflective buildings (especially glass-covered highrises used for businesses)?

At worst, the impact of solar panels would be comparable to a similarly sized metropolitan area.

> I would rather have a NUCLEAR REACTOR next to my home, rather then a WIND TURBINE, SOLAR FARM, OIL or COAL BURNING plant ANYDAY

This might explain your lack of rational thought processes; perhaps you've lived too close to them for some time.

* Wind turbines do have an issue with bird deaths. This is a very valid concern, and is a problem being worked on today. But, if this is the *ONLY* problem, compared to the HORRIFIC problems associated with nuke plants, your sense of what's best is severely skewed.

* Solar farm. Well, so far, of all the solar farms in existance, NONE have shown detrimental effects to the surrounding environment. N O N E . As in, NO patches of dried up grass (there is enough ambient light to fulfill their solar requirements), wildlife seems to enjoy the shade, rather than hide from it, and sometimes, birds even nest underneath them. Meanwhile, our cities are just smothered with blacktop coated, full-solar-exposure parking lots creating lots of waste heat for nothing. We could solar-farm these parking lots (just like Google, Inc. is doing), providing both protective shade (preserving the life of car interiors too, thus improving resale value of cars!) and power generation. We can put solar panels on the rooftops and the sides of buildings, of all city buildings, which otherwise have black, tar-coated shingles and/or pebble beds exposed to the sun. And, let's not forget that the USA has a *massive* amount of desert land that is just begging to be harnessed for both wind and solar use.

* You don't list geothermal, which is also an important energy source too. Are you aware that the Earth is a giant heatsink? Dig six feet into the ground, and the temperature is a nice, cozy, 58 degrees, consistently (give or take a few degrees for which latitude you're at), year around. Large-scale, low-temperature differential Stirling-cycle engines can be utilized to take advantage of the temperature differences between surface air and subterranian temperatures, both in summer and winter times.

> In fact, I WOULD PAY for a NUCLEAR SUB/AIRCRAFT CARRIER generator for use in my town.

And if you lived in my town, I would make every attempt to have you removed from said town immediately, with force if necessary. I will not have any fissile material anywhere near my place of residence, nor place of employment. Your reckless abandon and disregard for your fellow citizens demonstrates precisely the results of the USA falling so far behind other countries in science education. You're just rehashing the same blah blahs that we've all heard from the nuclear industry before. And, yes, nuclear does have SOME advantages. But, history has shown time and again that the WASTE issues haven't been solved, and it is precisely the WASTE issues that cause the problems none of us want to deal with.

In particular, when a fuel rod is "used," it actually has transmuted only 3% of its Uranium. ONLY THREE PERCENT. The other 97% is totally wasted, because the reactions are too hot for the power plants to handle. So, we stuff 'em underground, where they'll just have to sit for at least a few million years while the dang thing decomposes to acceptable radiation levels. That's just brilliant. Real brilliant.

Ah, but you can always use neutron sources to hasten the decomposition, and then use a breeder to recycle the fuel rod. This is what France does, after all. But neutrons come from somewhere -- yes, they come from electricity produced by other fuel rods. So now, the "fuel economy" of the use of nuclear falls significantly. And, even then, the laws of thermodynamics says that you can never recycle a fuel rod to precisely its original state completely, so after a while, the rods have to be thrown away. And, yes, they're "hot."

So between the mining required for U238/U235, the necessity for breeder reactors, the necessity for neutron sources, and the horrible environmental impacts of spent rods and the decomissioning of nuke plants, I'll take a few dead birds in my backyard ANY day. They at least bio-decompose.

Actually wind farms do disrupt the wind. You can't stick one row of turbines right behind another. But I don't see this causing any environmental harm, it just causes disputes over "wind rights." Wind farms do disrupt the landscape, as to work really well they must be tall. On the other hand, they make great sense on the top of tall buildings in windy cities.

As for the nuke, I have to say there is a compelling argument if you believe the worse end of climate change predictions. That's because those predictions involve the displacement of billions, the deaths of millions and huge costs. You could take all the nuclear plants built and more, and take all their waste and grind it up in the wind and you would cause huge damage, but a drop in the bucket compared to those predictions for global warming, as a result of the coal we're burning while we are afraid of solving the nuclear waste problem.

I'd just like to note that Geothermal is really just a special case of nuclear power, most of the heat that comes out of the earth is caused by radioactive elements decaying deep within the earth and giving out heat. Even solar energy (and it's resultant winds from heating of the air) is just given to us by our best and safest nuclear reactor - the Sun. It's really just a matter of how far and how well shielded we are from our nuclear energy. Thankfully the sun is a long way away, and we have a protective atmosphere and magnetic field deflecting a lot of the nastier forms of radiation the sun flings our way. Geothermal is good as well, since the reaction is deep in the earth, we are relatively safe from it (and well shielded by the earth under our feet).

Tidal energy is kinetic energy of the moons orbit being drawn off as far as I understand it, but this "gravititational" energy is the only other true source I can think of.

i thought geothermal energy was a relic of when our planet was a molten hot ball as a result of asteroid bombardment. my understanding was that the friction caused when an asteroid hit the surface caused this heat, and the sheer mass of our planet had kept it from cooling.

No, that's not the case. One can calculate how long it would take the Earth to cool from a molten state to its present temperature, and the timescale is much too short compared to that which geology and paleontology require. Before the discovery of radioactivity, this was a real problem. Check out Lord Kelvin's estimate of the age of the Earth.

I agree with most of this

I'd just like to note that these horrible cities are actually the most efficient way for humans to inhabit the world. It is the rural folks (like me) that have the biggest footprint.

In the desert where you have acres and acres of solar panels there usually isnt much plant life to begin with. If its personal use solar panels can go on your roof or be used as a porch awning. New glass mounting alow enough light through to still allow plant growth. Passive solar can be used for heating. In new arcitecture its even being uses for cooling. Most batteries can be recycled after the life of the battery, grid tied systems dont need batteries. The idea that wind and solar systems cause fluctuations in weather is a myth. I also dont have a problem with nuclear. I believe in improving all such technologies.

Then quit talking and pay for it.

You said "And as far as wind energy goes...what do you think happens to the environment when the wind is STOPPED at a certain point? "

You are wrong with this line of reasoning. Wind turbines will never stop the wind. The wind is constantly generated by a combination of the rotation of the earth and the heat produced by the sun's radiation. So, the windspeed just downwind of a turbine will be slightly slower than it would otherwise be, just like the wind downwind of a tree or building would be. We could never stop the wind, even if the whole planet was covered in wind turbines.

lol these are the people who are against nuclear power. I dont have a long enough attention span to read all the other comments so i hope im not restating something but probably am.
1. heres full lifecycle: mine the uranium - purify it - get energy from it - store the waste
nope i dont see any bad stuff in there (or more accuratly worse then other power plants itd be great if all but get energy were gone)
2. i have no clue what you mean decommisioning cost i dont intend to be decommissioning my shiny new nuclear plant any time soon
3. no ones covering anything up about nuclear power plants with millions of you conspiracy dudes watching them constantly then making crap up when you cant find stuff their covering up.
4. OH CRAP THEY USE WEAPONS GRADE PLUTONIUM IN NUCLEAR POWER PLANTS!!!!! thats what id be saying if that were REMOTELY true in reality stuff used in nuclear reactors 1% pure weapons grade is about 97% pure. Infact i heard somewhere we are thinking of selling off the some of the stuff or other so other countries can use it.
5. wth? sounds like you think the building of the plant is gonna make people more money then the energy from the plant.
6. solar wind and wave are great but ever seen one of them? they in great huge fields and they dont produce as much (dont know the ratio sry) as nuclear plants do. im not so much worried about cars in this cause cars wont be running on nuclear in my lifetime and will be running on electric in a good while(im hopefull for soon but reality isnt so) so they wont be running off nuclear indirectly either. plus there was some deally about if we ran off biofuels wed have to use every crop made in the US and still wouldnt have close to enough.
7. so you wanna go the lazy route and conserve for a coupla years and let the later generations deal with the problem huh?

I wouldnt worry about terrorists turning spent uranium pellets into weapons grade plutonium(which would likely be used for a stirling, stirling engines do not need tons of heat, and even spent uranium can produce a lot of heat, just not as much as a nuclear power plant would want.)

It's not like you can just grab uranium and pop it into a nuke and destroy the world. It needs to be enriched, purified, and processed heavily, and the source needs to already have some level of purity for it to become unstable enough to be used in a bomb. even if they managed to purify spent uranium, they'd succeed in blowing up a house at the most.

Also, it should be noted, enriching uranium is no small task, it takes a long time, a lot of energy, and a large complex that can enrich it. Centrifuges, all that fun stuff. Even then you're lucky if even 1% of your yield is worthy of making a potent bomb.

The long term fallout of an actual nuclear blast is trivial, just ask the folks in Nagasaki and Hiroshima. Those cities are incredibly developed and the radiation is very low. The problem with nuclear war isnt the nukes themselves, but the amount of destruction they wreak, and the amount of dust, fire, and smoldering remains of formerly living creatures that they kick into the atmosphere. While it isnt great, it isnt as bad as say, a nuclear power plant going china mode, where there is still material around.

The biggest problem with nuclear power plants is human negligence. It amazes me that there tends to be more negligence with nuclear power than any other type of power.

That would be my only complaint. A Safer power plant would have to be one that uses banks of stirling engines that power off of nuclear waste. spent uranium, etc. the uranium wont get nearly as hot as uranium used in steam powered nuclear power plants, so no china syndrome. All while still producing enough heat to power a stirling generator... or a series of them.

I am looking at the same idea only to power a narrow boat on the english canals. A company called WhisperTech in Australia, currently makes a stand alone sterling engine rated at 800 watts. These are available here in the UK and are being fitted into boats as generators with heat exchangers to provide hot water and heating.

I heard rumors that the engine burn out can anybody confirm it, this came from a dealer in the wispergen network the have a problem with quality controle

To Dartlavi:
Which dealer did you speak with? Have you developed any prototypes yourself?

I believe WhisperTech is a New Zealand firm, not Australian (much as I'd love to claim them). Their main product is branded Whispergen. And I can easily see them used in that application - they're small, and you could (depending on the draft of your narrowboat) potentially run them with the cold sink in the water and the hot side exchanger plumbed above a small, cozy peat fire.

The major advantage of Stirlings is not their size:output ratio so much as the fact that their fuel is essentially free. Often the simple thermal differential between a body of water and the air above is enough to keep them spinning. Might be enough for your application - Narrowboats aren't exactly the sort you'd use for water skiing. Zero carbon footprint, very easy on the operating budget.

How can steam engines be made to come to temperature quite quickly?

In the 1940's there was an american company that produced steam engine cars that could be run 30 seconds after start up.

I think the idea is not to heat the whole bunch of water in one large tank, but to heat a smaller steam generating chamber with heat exchanger mass hot enough then squirt small amount of water on it. The water will be converted into steam practically instantly.
The time required to rise heat exchanger temperature would be a lot less.

Several steam car companies of the early twentieth century, White, Doble, and Delling, had a water tube type boiler. All that means is you have water that flows upward through a coiled tube with a burner above it. As that water reaches the top it becomes steam and then super heated steam. Those types of boilers could generate enough steam in thirty seconds, from dead cold, to get you going down the street.

This is over simplifying but it's basicly a flat plate getting heated by flame,and water gets sprayed on the other side,flashing into steam.

You say that diesels are "any fuel" engines,
try gasoline in one !

In theory, at least, Herr Rudolf Diesel's Engine is supposed to be able to burn any liquid or gasseous fuel. Now, that might mean designing each engine to handle each fuel type best, and adjusting the timing of the injectors just so the burn occurs precisely when it should.. Diesel's actually spray a jet of fuel into a chamber of compressed hot air, whereupon the fuel burns as it gets sprayed in, so Diesels are supposed to be more universal. Methanol can be used in a properly adjuted and designed Diesel, as well as the oily fuel types. And, they're supposed to be more efficient than Gasoline engines, maybe because they run hotter? Anyhow, what happened when you put gasoline into the engine?? :> That must have been exciting!

OMG, you have no idea what a Stirling engine is, do you! They don't have to be huge, they don't need radiators and they don't need huge amounts of cooling. You work for Big Oil don't you? :)

One of the reasons it is the most efficient engine on the planet, is that it only requires a slight difference in temperature. A candle can power it. The size of the piston determines how much power you can make.

Have you seen the whispergen? It's a commercially available Power Producing Stirling Engine. It's completely self contained. There must be vents but I can't see them on any of the photos. Also a Stirling generator would triple the efficiency of any HEV or PHEV.

I could even go one step further than just a Stirling. I could buy a steam configured Quasiturbine and use it as a Stirling. Look it up.

Actually, they do need a radiator if you're going to maintain a constant temperature on the cold-side of the engine. Air-cooled, high-power engines don't have the heat dissipation surface area to maintain operation for extended periods of time. The engines you talk about are all "LTD" (Low Temperature Differential) engines or engines of insignificant amounts of power, and are thus able to be air-cooled. But, so was the VW Beetle engine.

If you want power, you need liquid cooling (and probably liquid heating too), because there is no better way to exchange heat.

It is about the most efficient engine on the planet, yes. But the size of the piston isn't the only determinant. The actual temperature differential that you're mining has a large part to play. The rest is basically plumbing.

I like the idea for a Stirling Electric Hybrid, but not for a car. The combination of a very efficient Stirling engine, with a light enough battery pack and electric motor to augment the Stirling when it could not make optimum power, would be a theoretically superior light aircraft engine.

The problem of power to weight/size would have to be overcome, but I have seen several designs floating around the web that claim to be close. With funding and brains, someone will make it (or something like it) work.

Because Stirlings operate on a difference in temperature between the hot and cold sections of the engine, the efficiency (and theoretical performance) of this type of motor increases with altitude.

The Stirling's basic difficulty with quick power/rpm changes is far less relevant in an aircraft engine, where power settings are not changed quickly or often.

The need for large radiators on a Stirling engine would be offset by the constant flow of cold, high altitude air. The Stirling would not make very much power for take-off at sea level, where the temperature difference between the hot and cold side of the Stirling would not be very high (and difficult to increase artificially without adding weight and complexity to an already complex design). That is where a light battery pack and electric could be useful, although it would not be a hybrid in the same way a Prius is, because you would not have any real potential for regenerative charging of the battery - a propeller efficient enough to windmill power back to the battery during descent would be difficult to design in a way that passengers would buy into("Er, yeah, the engine actually isn't running; that's why it's so quiet...").

Speaking of batteries, until some major and scalable breakthrough happens in battery technology, the key advantage to a Stirling Hybrid for aircraft (like the Prius) would be fuel savings, not performance or payload gains. The best you could hope for is a net zero change in either, because the weight of whatever fuel you saved would certainly be offset by the weight of even small batteries and an electric motor. In fact, if you graphed the lines between what it would take in electrical energy to augment the weakness of the Stirling for sea level operations and take-off and what all of this would weigh, you'd likely end up (at least today) with something fairly underpowered with very little payload.

But remember, the Wright Flyer was grossly underpowered and had very little payload. So we just need to keep after it. Lycoming, Continental and Big Oil can't hold out forever.



...then the car to power with Sterling is, I think, a farm tractor.There are fewer problems with speed, manouverability and mass, and for energy(fire) they can use byproducts(straw,wood, different agro waste).Like old trains that had coal cars, tractors could have trailer compartments for solid fuel, and a Stirling-electric hybrid would make sense(with battery bank just big enough to allow for some flexibility in manovering the thing, since the engine tends to run better at constant rev.I don't think a big radiator is a problem on a big, slow, farming tractor.And the fuel would be renewable and wouldn't need much industrial, energy an money hungry processing.

Is t really possible to power stirling engine driven car by solar heat and wat r d really prob arises

Problems arising are the mass/energy ratio.The engines are much biger and heavierthan ICE for the same amount of power.The sun energy you would need to power a small car would have to be collected on a big surface, many times larger than the car itself, so really the sunshine alone without concentrating is not enough.


How much do you know about Stirling engine autos? You probably didn't know that every one of the former "Big Four" car companies, except Chrysler, developed a Stirling engine automobile; Ford partnered with Philips to make a Stirling auto, American Motors partnered with NASA, and General Motors was working with Stirling electric hybrids, originally as a space power source experiment. The only reason they were not mass produced is that the manufacturing costs, of the time, were too high, there were a few engineering flaws, including thermal efficiency ratings, and the lift of the Carter Era oil embargo. Ford and General Motors both have the data and the ability to manufacture an inexpensive Stirling engine auto with the new materials of today. Also, the part that Brad is talking about is the displacer cylinder. No combustion takes place in the engine itself only within the combustion chamber, which heats the displacer cylinders.


I agree with Sean about Stirling engine autos not needing a significant amount of time to heat up. He just didn't give a good example. Ford had their Stirling where you could turn the key and drive away in less than a minute. By the way, you could not , in theory, put wood in an automobile Stirling engine and drive. There is no possible way, unless you removed the combustion chamber, set the wood directly on the displacer cylinders, and started a fire with a match. I don't think you would want to do that.

I believe it would be cost effective and environmenally sound to apply solar stirling engines to residential electrical power. Along with powering your home, I believe you could also charge a battery for an automobile for short trips.

Just to say you that your dream to put nuclear energy
in a car is now possible with working Cold Fusion, as
implemented by Defkalion Green Tech, and Andrea Rosssi Ecat...

... thanks for the comments on Stirling... instructives.
bytheway cold fusion is not pathologic science, it could even probably respect standard quantum mechanic (if Widom-Larsen theory is right)
keep tuned.

I think we could make it we can use gas as a cheap fuel instead of other and i had made a group for doing this and addng up some engg plz join the group and help us.

In his extensive comment, Sean refers to the Prius engine as a "Miller cycle" engine. Is that another name for the Atkinson cycle?

Some of the inefficiency of the Otto cycle engine is that much of the compressed gases that are created by the combustion are released as exhaust before they have fully expanded; an Atkinson cycle engine uses a compression stroke much shorter than the power stroke, so it can extract more of the energy before exhausting the gases. The trade-off is reduced torque, and lower power for a given displacement than the Otto cycle.

I know the original post is what, ten years old? I can't help myself! He he. I've always found Stirling's fascinating but had never really seen a large engine, or even knew they existed for that matter! When I get old my goal is to basically have a zero dollar living expense for as many things as I can, and get the rest really low! :). solar and wind as well as any strange and interesting tech really gets me excited!

Last year my wife and I were at on of those 'antique malls', you know, where most of it isn't really antiques and most everything is outrageously priced, heh. Anyway I had navigated my wheelchair over to the front corner and saw a pile of old Mechanix Illustrated (yes, with an X!) From the late 1970's. A good number of them had alternative energy stuff on the front cover. Oh yeah, energy crisis era!! I started rubbing my hands together in glee! ;).

I bought almost the whole stack of twenty-something magazines. When I got home and started looking through them I couldn't believe all of the great ideas and totally functional and practical devices that they held between the glossy covers of goodness! Why aren't we using most of these things today? What industrial greed and political hypocracy has stabbed our countrymen and women in the back and hurried these treasures in the name of the almighty dollar?!

They had a winebago RV with a 6.5kw stirlng generator that powered EVERYTHING on the rv, even the stove, no propane here! The radiator for it was on the roof and an integral part of the two ton AC unit, and it also served as the hot water heater and battery charger/inverter! Outside of the radiator it didn't look any bigger than the generac on my rv.

The mags also had a variety of easy, cheap to make solar hot water heaters, radiant heat wall sections that could be put in place of w section of brick wall that used the sun to heat tubes of water in the wall, which in turn could have a fan blowing over them at night to heat the house for the cost of only the blower fan running!

Solar hot air heaters built on to the side of the house both active and passive. ...and the list of mechanical wonders that never made it to market b t should have, even if it took someone else to do it.

...I found a webpage the other day (or the like) and the guy was collecting data and evidence of every vehicle out there that had ever run on a stifling engine. The list was really quite impressive considering I'd never heard of one!

Check it out! Some of those cars are pretty small too! (Well give up on trunk space, he he). ...yet again, other than companies building and testing them they seem to go the way of the dinasour:( ...reminds me of watching the documentary "who killed the electric car"

...ah well, things are improving a bit, but its taking soooo dang long for positive change to occur!

...I think I'll get back to reading about the virtually free HVAC system that basically consists of a bunch of thin-wall sewer pipe, a blower motor and a decent size back yard to pull it off! :)

Mmmm, as seen so often, an argument limited by the familiarity of current 'consumer available' technology! Potentially (without the $Bn's spent on the IC engine!!)the Stirling/Carnot cycle engine can be vastly more efficient - it just needs to be used in a different way. And why not spend the money on it anyway? The engine powering the car most of us go to work in (even allowing for recent variations) is one of the most horribly inefficient, dirty, noisy, machines invented by man! It's only still in use due to the laziness of the scrooges who run the motor/oil industries Oh, and their paid lackies in governments all over the world!!

Turbines, well they've been about for over 60 years now. The first 'production' car was a Rover in the 1950's. The fact they're not in common use should tell you something!

Nuclear power clean? Well, no CO2 emissions, but as to everything else; how can we tell how efficient it is when NO government tells the truth about construction and maintenance/running costs. Plus the security angle.

And you ask how clean nuclear power is of anyone who's had to have two guys with stiff brooms give every single inch of their body a going over after a leak.......

"Turbines, well they've been about for over 60 years now. The first 'production' car was a Rover in the 1950's. The fact they're not in common use should tell you something!"

Ya, it tells you that Brayton cycle engines in a small / lightweight configuration have even LOWER thermal efficiency then otto cycle gasoline engines. Combine that with sluggish throttle response unsuitable for typical automotive use and you will realize that big oil has nothing to do with why turbines are not utilized in automobiles.

If anything, big oil would love it. I'm sure they smile every time they see an M1 Abhrams tank roll by. Turbine powered and the worst fuel economy of any tank in the world.

Gasump quote -

Turbines, well they've been about for over 60 years now. The first 'production' car was a Rover in the 1950's. The fact they're not in common use should tell you something!

By that logic the Stirling is also a dead issue.

For my part, I believe the best way to incorporate a stirling into a vehicle is to use it to harness the waste heat generated by a Diesel or Otto. How about a hybrid system like the "Through The Road" system proposed by Chrysler and others where the front or rear set of wheels is powered by a conventional engine and drivetrain and the other wheel pairing is driven by a battery set and wheel motors. With the two systems operating independently and a computer monitoring the interaction between the two. The idea being that the electric set would charge through regenerative braking, and while running at road speed pull a little on the IC engine to top up the battery set.

The practical upshoot of this proposed hybrid is reduced cost by using the exsisting driveline without needing to modify it to interface with the electric. The other benefit is that it actually offers a performance improvement by offering AWD and the availabilty of the high torque electric motors to move the car faster with a smaller more efficient IC engine. Making the Hybrid a performance enhancer will improve it's marketability.

The Stirling fits in by charging the batteries continuously during the IC operation, not by sapping the IC power on the road. The regenerating charge wouldn't be suffcient to keep the batts topped up without using some of the IC power charging. with the stirling on the job the IC will be able to be trimmed even more offering greater economy. If the batteries were charged the stirling could send power to the wheelmotors to ease the burden even more on the IC.

Introducing and gaining public acceptance of unfamiliar technology has to include a real tangible benefit for the consumer.

Just a thought. What would that be a Tri-brid? :)


I've heard references to a some '70s GM stirling
engine based proto-types. These could start in
under two minutes, and where supposed to be part
of a solution to the oil crises at the time (now
we just invade other countries...). The 2 minute
start time was still too long. Sorry I can't
provide any solid references (I've been looking
for some for a while). But I feel that car sized
stirling power plants do exist....


I am so sick of liberal tree what is it, invasion for cheap oil or invasion to make Cheney's oil barons richer....dude get over it all ready!

Get over it? Why don't you tell that to the 100,000 + dead Iraqis. I may be a tree hugger but at least I'm not a Nazi lover.

By the way Nazi is an acronym for The German peoples party, "of course in German" a leftist organization. Also the inventors of political correctness.

New nuclear reactors produce only 6 % of the waste of the old reactors. Europe is ripping out the old fossil fuel power plants and installing the new fast neutron reactors as fast as they can. Also the waste from these will only last 300 years instead of 10000 from the old and cannot be used for bombs. The waste from Coal and and other fossil fuel plants is greater than a complete nuclear plant, is chemical, and is forever and they are dumping it all over the place.

Power windmills kill migratory birds by the thousands and are noisy, foommm foomm foomm like water torture never stopping. Not even theoretical solutions to this one.

Solar has not enough horse power per square foot even at 100% conversion. And the waste is really nasty never go away poison.

Wave power looks good but will not work everywhere, Environmental impact on a large scale is still a question. A lot of the ocean life depends on waves. Smaller waves equals less oxygen in the water and some other problems. Good to reduce beach erosion though.

Sterling engines can stretch what we have though and can pull power out of thermal differences nothing else can, even if they are big. At least if they don't have to move it's not quite the problem.

We need nuclear power but we need to use as little as possible. Just replacing incandescent lights with the new white light LED lighting coming out just now would mean we didn't need a new power plant for close to thirty years.

Most of what you say is wrong:
burned out nuclear fuel is always the same amount and directly linked to the power production. The waste will last 10 half lives of plutonium and strontium, no way around that either. and this is more than 250000 years. Power windmills kill no nearly no birds. I looked under 2 600kW engines for a Year and I found none. I also had a holiday at the seaside, and within 3 weeks, I looked every evening and founs one seagull bviously hit by a flap. Around me were millions living and flying from land to sea in the mrning and comeing back in the evening.
I dont argue on noise, one goes into discos if he wants to dance and suffers from the hum of a bee if he wants to sleep.

Glad Nuclear is getting better, but everything has drawbacks. Best is to go with Intelligent Designs for efficiency. We could have a hoppin' economy on less than 10% of current energy consumption, but it requires common sense to go that route, and a little reflection on the matter. Keep all the possibilitied out there, but look at use, and therein lies the biggie; the veritable motherload of all energy solutions. Efficiency is the answer.

> Nazi is an acronym for The German peoples party, "of course in German" a leftist organization.

What the heck? I wonder why they didn't get along with those other leftists in Russia then. While the definition is open to interpretation I think Nazism lands clearly in the fascist category:

And fascism, being primarily authoritarian, skewing to the conservative/right, not left.

(more interesting discussion on various political spectra here: )

"The main plank in our program is to abolish the liberal concept of the individual and the Marxist concept of humanity, and to substitute for them the Volk community, rooted in the soil and united by the bond of its common blood."

On balance, doesn't seem to support an affiliation with the left.

But anyway, I agree. Nuclear isn't as bad as its detractor's make it out to be (especially in comparison with other, dirtier, forms of energy that are already widespread and pollutant today), but that doesn't mean we shouldn't use common sense and new technology to conserve, be more efficient, and recycle. There's no reason we shouldn't do BOTH (find better energy sources, reduce waste of current energy).

Please keep your ignorance to yourself. Your invasion for cheap oil costs this country billions. In no way can it be justified morally, ethically, or financially. Your a moron and your parents were morons. Hug a tree, so your children have an Earth to grow up on, or better yet self sterilization would be best for society.

The final report for this project is:

Ernst, William D. and Shaltens, Richard K. (1993), "Automotive Stirling Engine Development Project", Final Report, NASA Contractor Report 190780, MTI Report 91TR15

The Abstract, part of the Summary, the main headings from the Table of Contents and the Conclusions from this report are reproduced below.

The development and verification of automotive Stirling engine (ASE) component and system technology is described as it evolved through two experimental engine designs: the Mod I and the Mod II.

Engine operation and performance and endurance test results for the Mod I are summarized. Mod II engine and component development progress is traced from the original design through hardware development, laboratory test, and vehicle installation. More than 21,000 hr. of testing were accomplished, including 4800 hr. with vehicles that were driven more than 59,000 miles. Mod II engine dynamometer tests demonstrated that the engine system configuration had accomplished its performance goals for power (60 kW) and efficiency (38.5%) to within a few percent. Tests with the Mod II engine installed in a delivery van demonstrated combined metro-highway fuel economy improvements consistent with engine performance goals and the potential for low emission levels. A modified version of the Mod II has been identified as a manufacturable design for an ASE.

As part of the ASE project, the Industry Test and Evaluation Program (ITEP), NASA Technology Utilization (TU) project, and the industry-funded Stirling Natural Gas Engine program were undertaken to transfer ASE technology to end users. The results of these technology transfer efforts are also summarized.

SUMMARY (partial)
The objectives of the Automotive Stirling Engine (ASE) Development project were to transfer European Stirling engine technology to the United States and develop an ASE that would demonstrate 30% improvement in combined metro-highway fuel economy over a comparable spark ignition (SI) engine in the same production vehicle. In addition, the ASE should demonstrate the potential for reduced emissions levels while maintaining the performance characteristics of SI engines.

Mechanical Technology Incorporated (MTI) developed the ASE in an evolutionary manner, starting with the test and evaluation of an existing stationary Stirling engine and proceeding through two experimental engine designs: the Mod I and the Mod II. Engine technology development resulted in elimination of strategic materials, increased power density, higher temperature and efficiency operation, reduced system complexity, long-life seals, and low-cost manufacturing designs. ..........................

(The remaining part of the summary contains essentially the same material that is contained in the abstract)


This final report has summarized work performed in the ASE project. The project's success can be determined by comparing accomplishments to the defined project goals and contract requirements. In so doing, the following conclusions can be made:

The potential for improvement in fuel economy for Stirling engines over SI engines has been demonstrated. A 10 to 13% improvement in fuel economy for the Mod II over the SI engine has been demonstrated for the USPS LLV in the EPA driving cycle. Based on test data obtained with the LLV, if the original Mod II Celebrity vehicle had been retained for fuel economy demonstration, the project goal of a 30% improvement could have been achieved. The Mod II engine had been sized and optimized for the Celebrity. Component optimization would also provide further improvements for USPS LLV fuel economy.
The potential for low emissions has been demonstrated in the Mod II engine: CO=<2.2 g/mi, NOx=<0.9 g/mi, and HC=<0.4 g/mi with gasoline. The 1985 Federal emission limits were easily met without using a catalyst.
The ability to operate on a broad range of liquid fuels was demonstrated. This evaluation was achieved not only in an engine test cell but also in vehicle operation.
Measured Mod II SES [Stirling Engine System] power and efficiency performance was in excellent agreement with analytical projections, i.e., the differences were less than 4% in power and less than 1% in efficiency.
Vehicle performance of a Stirling engine can be predicted from engine dynamometer test results. The Mod II-powered USPS LLV prediction of a 10% fuel economy improvement in the EPA driving cycle over the comparable SI-powered vehicle was verified by experiment.
A manufacturable Stirling engine automotive design has been identified under the project. The engine is the Mod II (V-block design with annular heater head) concept modified per the Deere & Co. VA/VE study. Manufacturing costs of $3500 to $4000 were projected by Deere & Co. for commercial production of 15,000 units per year.
In accomplishing the objective of transferring European Stirling engine technology to the United States, the ASE project succeeded in establishing an extensive U.S. technology and vendor base capable of designing, developing, and commmercializing Stirling engines. As a further indication of successful technology transfer, MTI, along with a gas industry consortium (GRI, NYGAS, and others) and Hercules Engines, Inc. of Canton, Ohio, is developing a commercial Stirling engine based on ASE technology developed in the Stirling Natural Gas Engine Program.
The NASA TU project demonstrated the ability of a Stirling-powered vehicle to be operated over the road by non-Stirling personnel; it demonstrated adequate availability and drivability.

The above report is for sale by the National Technical Information Service, Springfield, Virginia 22161

Last updated: Wednesday, May 3, 1995

I had never heard of a sterling engine before today when I picked up a June 1974 popular science magazine. Very informative article concerning the research of the day. In short, Phillips research Germany, Ford, et al developed working modes using the sterling.

hey all,
it seems to me that pretty much all the energy we use ends up as heat, right? in our cars we produce primarily heat and we just throw it into the atmosphere out the radiator and the exhaust. my question is has anyone ever tapped into it and made that waste heat work for us? i.e run it through a low temp. stirling cycle to charge some batteries (which could be sometimes used to run the car)? I am keen to give it a go, but i'm going to need some help - has anyone out there tried anything like this before?

Dear Ravo

I will be graduating from the Goergia Institute of Technology with an MSME this December. My area of concentration is in the thermal sciences and experimental fluid mechanics. With regars to a waste heat recovery based TryHybrid system, I must mention ( in case you do not already know this) that due to the second law of thermodynamics heat transfer from a source at the temperature of a radiator (220-240 deg F) would yeild a maximum ideal efficiency of 23% and even a sterling cycle would only give you about 1/2 to 3/4 of that. Accomplising anything significant would require attacking the problem from multiple directions at once.

First of all one would need to minimize power consumption. Therefore cars need to be made lighter, while retaining thier structural strength. Some of the new carbon composite materials that have been developed might make this possible. Second while alot of work has been done on automotive aerodynamics, I am sure some additional investigations could yeild more practical solutions than the tiny two seatters you would see at a cars of the future show. For instance, active flow control, which is what I did for my masters thesis, could be used to reduce flow separation and hence reduce drag drag). Finally, a completly novel rearrangment of a car's power generation and powertrain system would be required in order to make a waste heat recovery based trihybrid practical. As an example, you want to run your engine hotter and transfer your waist heat directly from the engine and the exhaust as opposed to channeling it through a radiator system at less than 250 F or at least use a radiator and transfer fluid that works at higher temperatures say 350 - 450 deg F. Finally one must be completely open minded to the use of any type of engine technology weather its something tried and true or a new thermodynamic cycle that someone recently dreamed up. In general, when you begin you need to give at least brief consideration to everything you can draw on a P-V diagram that would not violate the second law of thermodynamics and see what the most practical configuration would be. Identifying one cycle as the holy grail is not the way to go. That has already been done one to many times.

If you or anybody else who participates in this blog have the capability to secure some startup capital,I would be glad to partner with you in starting up a energy systems/vehicle R&D and promotion company. If you or anybody else out their is serious about trying to do something please post another blog reply and mention that it is in reply to FluidMan.

Hi Fluidman,
You mentioned several times about forming some startups, where are you now at? I have some ideas to talk about.

I found an article on the net that a used air conditioning compressor out of a car and was used to make a Small Steam engine!!??

My eyes are going crossed trying to find out something more.. Any thoughts??

Mark Shaw --

Mark, If you would email me the link for that steam engine from a frige compressor I would be very grateful. I've heard it is out there but I can't find it. Thanks!

BTW: to all - Nazi is the National SOCIALIST Party - by its own definition a LEFT wing organization. BUT if you ever wondered where all those NAZI scientists went after WW2, research Operation PaperClip. It should make you think long and hard afterward.


Very many social democrats were killed by the nazis, for sure not due to the fact that the nazis were left! It is extremly wrong to see national socialist party as left.
In american relations it was say republican, but with killing jews and other people not to believe in Hitler.

You need to re-read your history books. National Socialism is not the same as Marxist socialism. National socialism is so-named because it believes in a single, superior race (a "nation" being defined as members of that race). Marxist (leftist) socialism is diametrically the opposite -- the happiness of man is dependent on elimination of artificial barriers introduced by race. National socialism believes strongly in corporate rule. Marxist socialism believes in power being distributed to all, from those with abilities to those in need (I don't remember the precise quote). And on and on.

Also, National Socialism acquired its name in the heyday of rising Marxism, so it makes sense that they'd try to cash in on that popularity by proclaiming themselves to also be socialist, when in reality, they were anything but. Nazism is pure, unadulterated military junta plus severe racial discrimination (in the extreme case, genocide).

I have researched this thouroughly with the A6 compressor and in my oppinion it's not practicle. All the reed valves have to be completely re-designed and there exists a mechanical disadvantage on the swash plate working in reverse.

I've been working on a Stirling/Electric Hybrid (in my head) for several years. I think it is a very viable idea. I plan to build one for myself someday.


I've read thru these post and seen ideas that look cute. Somehow I think we all tend to overlook the fact the others, likely much smarter than us, have had the same concept year ago with out any success.

If you want some good detail about engines checkout

Sterling engines are poor for cars b/c they have a constant rate of rotation and are slow to wind-up and then wind down. As stated, the internal combustion engine is muc hbetter at 'quick' access to power.

For all of the great stuff you'll hear about hybrids try to do some research of your own. Howstuffwork's shows that hybrids really only offer about 4% more efficiency over gas cars. What should be attractive is freeing yourself from costly arab oil, not engine efficiency.

They point out that people often forget to factor in the fact that that energy (in this case electric cell) need to come from somewhere at a given cost.

Before you buy your Hybird think about this. The battery in a Ford or Honda hybrid only lasts for five years max. After that it costs $2000-3000 to replace it. Yep, that's no Typo! calculate out how much money you would have spent in UNLEADED for 5 years and I bet your savings doesn't seem so hot after all.

Today's best alternative is likely Bio-diesel. Yes, vegtable oil that the folks at Wendy's and McDonalds need to get rid of. Sadly, it looks like most Americans won't even think about going back to diesel engines.

So, unless the Gov't does more to promote its adoptance we'll likely have to ride razor scooters to work.

Dear Ken,

your points are good, but Bio-diesel though renewable has a certain maximim rate of production, while the country's and the world's energy needs grow exponentialy. Bio-diesel and wood alchohol probably won't keep pace. So it makes sense to invest both time and effort to exploring ideas to make cars lighter and more aerodynamic. In addition if the primary engine system can be modified to premit adiquate wast heat recovery it might at least improve the performance of a hybrid system to a level that would make it worth while.

Some time ago, I was informed by wind enthusiasts and energy gurus that wind power, as well as wind resistance, is a cubic function. This is the biggest energy cost of the car - pushing wind! Probably why hybrids get better mileage in town than on the open road.. Of course, the ideal body shape would be something like a long teardrop, but we could do a lot better than the current bull-dog "muscle" look of these latest body styles.
On the weight matter, I agree - lighter would be better. But there are a lot of traction and control issues. On gooshie snow, one needs body weight for greater tire surface contact. Wind as well. So, body shape can cut the effect of side-winds, and maybe some type of newer tires could aid in grip? Seem to recall tires designed for light vehicles that do just that, but not remembering their exact design.. I thought about adding a snow-mobile track beneath my own car, maybe a studded track, that could be hydraulically lowered in emergency stops (heavy pedal to the brakes), to both align and quickly stop the auto. Also, light weight means more impact in collisions. Better crumple zones, and more interior padding? Better seat belt designs?? Thoughts welcome!
-from Chuck

> we could do a lot better than the current bull-dog "muscle" look of these latest body styles.

Indeed. The Dymaxion car, from Buckminster Fuller (same guy who invented the geodesic dome and the space-frame), was an astounding piece of work for its time. The body of the VW Bus was inspired by it to some degree. Unfortunately, he want too far with the teardrop design, because it only had a single, rear wheel which proved to be unstable. At least one accident occured because of it.

However, if you're willing to use racecar-like suspensions, you can put two wheels in the back, recovering stability without impacting aerodynamics too much.

The traction thing isn't really too much of an issue- a lighter car doesn't need to generate as much force to accelerate and so therefore the lower traction is acceptable. If you work out the physics, the mass actually cancels out of that equation.

You are correct in that wind resistance is a major factor in fuel economy. One thing to note is that on the highway running at steady speed, a hybrid car may as well be a regular car with a lot of extra baggage. The hybrid components have absolutely no gains whatsoever in fuel economy on the freeway. Their principle advantage is allowing you to recoup some of the energy which would normally go to heating the brake rotors, and use it for propelling the vehicle. The battery reserve / electric motor system also allows you to get acceptable acceleration out of a smaller electric motor by supplementing its power output (from the batteries) in a pinch. Anyways, as I said, none of that helps you at all in steady state, freeway operation- so you see freeway economy numbers similar to non hybrid models.

If you want to further improve, you can switch the gasoline motor in the hybrid to a diesel- the reason this isn't being done commercially is cost. Go look at the cost premium of a volkswagen "tdi" diesel model, then the premium for any automakers hybrid. Add them together, and you get a cost that would be unacceptable for most consumers.

The small weight of a vehicle does not hurt it much in collisions with a fixed object, a bridge / telephone pole / etc. While it has less support, there is less energy to be absorbed, and the acceleration tends to be about the same. Go check out the crash test video for the smart car...

Now, when it runs into a fully loaded ford excursion powerstroke, towing a trailer- that is when things will be bad. Due to the laws of momentum the huge car will have very little acceleration and the light compact car many times what it would have even if it hit something that was fixed (bridge, pole, etc). You can chase your tail trying to add more crumple zones etc, without increasing the weight- some gains are possible that way but it really isn't that practical. In reality, it just isn't possible to make it a fair fight, and there is little you can do about the large accelerations which will be present, other then to try to minimize the peak values (crumple zones).

Crumple zones can't really solve this problem as a zone that would work well against a pole wouldn't be optimum against a vehicle 3-10x its weight. Seat belts IMO are at the limit of what people will actually wear- odviously past it to some morons... Same goes with interior padding- that's basically what an airbag does and we've sort reached the limit for that especially in higher end cars, with front bags, side impact curtains.

"Somehow I think we all tend to overlook the fact the others, likely much smarter than us, have had the same concept year ago with out any success."

Everybody, quit inventing! It's all done! There are no more good ideas to be had! On your way out, please don't forget to thank Ken for realizing we are all too stupid to contribute anything new to the world.

Thanks, Ken!

"Everybody, quit inventing! It's all done!"

I don't think that is a good idea. "It's all been done" has been stated far to many time's in the past and has constantly been disproved. Scientist's will continue to discover phenomena that have yet been found or correlate existing phenomena to new applications.

Your self-defeating attitude is only defeating yourself and the others that follow you. Lift yourself and other up... not bring them down.

Also, check out the VW Lupo and Audi A2 specs. Those cars are the way to go. Especially, if you can use carbon fiber composite body structures and couple with re-generative breaking to re-charge your electric motor. Man, 81mpg would be your low end consumption.

your lack of appreciation for sarcasm is hilarious!

There HAVE been Sterling engines in commercial sized usage for many years. One use has been with a Sweedish submarine powerplant. Now if the military uses it, I think that a bit of development could make it more practical for civilian usage.

Regarding complaints about turbine engines lacking automotive performance, tell that to an M-1 tank driver. They are turbine powered. Quiet, fast, very high automotive performance. Fuel efficiency isn't great, but better than conventional internal combustion engines.
Now harness the heat of their exhaust and you could power a small town!

Of course we could still settle with the current arguement regarding the technology being impractical due to lack of it being developed the same way as previously: Under Abraham Lincoln the patent office director suggested the office be closed as "Everything possible has already been invented"...

Fuel economy is far worse then regular internal combustion engines. Even from a theoretical point of view, the brayton (turbine) cycle cannot come close to even the OTTO cycle, let alone the diesel cycle. The M1 abrams gets approximately 3x worse fuel economy then any comparable tank. It was designed to fight the soviets within 100 miles of bases in western europe- fuel economy and range were not an issue at the time. The main priority at the time was a huge amount of power for very fast speeds in a 70 ton tank, in a small package. These same constraints are why turbine engines are so prevelant in aircraft.

All that heat coming out the exhaust (~1000degF) in large quantities (big mass flow rate) should tell you something about the efficiency right off the bat. You know this by just intuition- even in your post you say "Now harness the heat of their exhaust and you could power a small town!". Also, the tanks are NOT direct drive off the turbine, so the slow throttle response of the turbine itself does not matter in that application. It does matter in an automotive application.

To really get a stirling engine cooking, you need high pressure of a small gas molecule (lots of moles). That is why hydrogen or helium are common choices. It's also why they are a real pain in the ass to manufacture. Then you need a lot of heat transfer through into the hot chamber- no big deal- but on the cold side, you also need a lot of heat transfer to get rid of the waste heat. In the end, you are talking about moving a lot of air and heat back and forth, and some high pressure vessels and dynamic seals that must be SPOT ON to have any sort of useful lifespan. Keep in mind that the throttle responce of a sterling engine is only as fast as you can heat up or cool down and cause heat transfer across the chamber of the hot side- so it would only be practical if used in a sterling / electric configuration.

Someday it might work, put enough pressure in it and get enough temperature differential across it and you might just get the power output you need for a car. Currently however, commercial sterling setups aren't even close to the energy density we need.

Look at those units on the dishes from sterling energy systems. Each dish is 25kw peak. They are concentrating heat on the collector up into the thousands of degrees, and the low temperature resourviour is ambient temperature. Now, consider the size of that engine package- and 25kw = 33 horsepower.

Here is a picture right on their homepage:

A lackluster automobile these days is ~120-140 hp, and the latest heavy hitting iron is 550+..... The energy density is not even in the ballpark yet.

FYI, NASA has built stirling engines for electricity generation in space, i find the radioisotope based systems the most interesting, and promising.Also Stirlings can be used to turn solar heat into electricity (through mechanical energy ofcourse), at efficinecies around 30 %.
Just do a google search on "solar stirling", or "NASA stirling". Btw it's spelled "Stirling" not "Sterling". "Font Sterling" is a currency.
There is nothing technological that would stop stirlings from being used in vechicles.
Oh, and about "much smarter" guys thinking about something, and seemingly failing...thats what they want you to think...but that's another topic.