Talk-Polywell.org

ohiovr wrote:

Skipjack wrote:

ohiovr wrote:I was wrong:

http://www.nature.com/nature/journal/v5 ... 13184.html

It has a upper temperature limit of 923 K (211 K away from its melting point) and therefor a absolute efficiency of 27%

Wow, 27% would be very interesting! Nuclear battery anyone?

Generational battery. Every 68 years you got to take the strontium in for refinement

Nope, it has 10 pellets. Every 30 years you put a new pellet in and remove the oldest. (FIFO) The old pellet is thrown away.

BTW Thanks Tom I haven't forgotten the post I've just been lazy in my reply.

Thats interesting though, these particular modules, probably don't output much power due to their low temperature spread. But at any rate by a crude measure, this is around 10 cents per watt handled, though not really producing power but absorbing it.

I think that it maybe possible to attain a module that will operate at combustion temperatures for as little as 10 cents per watt. This is still too expensive for most cars as a primary power plant. But I know of something even more fantastic than SnSe based thermoelectrics and that is colossal graphene based thermoelectrics. Some studies show that a ZT of 20 could be attained and one researcher has already attained a ZT of 3.0 with real materials. This is a totally different technology than the czochralski process and will require a lot of time and money to make it work. But if they can make it work, there would be no built in material scarcity. These devices could have efficiencies of 61% (due to high temperatures and ZT) and cost a penny per watt. If this kind of technology existed, the internal combustion engine would be doomed. We would have thermoelectric powered helicoptors. The military would use RTGs to power tanks... HA! Well maybe not...

But what I really like to see is a 61% solar power plant based on graphene thermoelectrics. At a penny per watt your 2400 watt collector could cost $24 (thermoelectrics) + a couple hundred dollars in plates and piping. The concentrator can be made for 800 bucks or less. So a 2400 watt system could cost as little as $1100. At that cost, every land owner will have these except where it is too cloudy all the time or cold.

ohiovr wrote:BTW Thanks Tom I haven't forgotten the post I've just been lazy in my reply.

Thats interesting though, these particular modules, probably don't output much power due to their low temperature spread. But at any rate by a crude measure, this is around 10 cents per watt handled, though not really producing power but absorbing it.

I think that it maybe possible to attain a module that will operate at combustion temperatures for as little as 10 cents per watt. This is still too expensive for most cars as a primary power plant.

I am confused. Why is that too expensive? If it is 10 cents per Watt, then we have 100 USD per kW. A car does not need 100 kW of sustained power. So you can get away with maybe 10kW of continuous power and a capacitor, or a small battery to provide a buffer for those times when you accelerate and need a lot more than that. Plus the battery would get charged while the car is sitting in the lot, braking or idling too.

Skipjack wrote:

ohiovr wrote:BTW Thanks Tom I haven't forgotten the post I've just been lazy in my reply.

Thats interesting though, these particular modules, probably don't output much power due to their low temperature spread. But at any rate by a crude measure, this is around 10 cents per watt handled, though not really producing power but absorbing it.

I think that it maybe possible to attain a module that will operate at combustion temperatures for as little as 10 cents per watt. This is still too expensive for most cars as a primary power plant.

I am confused. Why is that too expensive? If it is 10 cents per Watt, then we have 100 USD per kW. A car does not need 100 kW of sustained power. So you can get away with maybe 10kW of continuous power and a capacitor, or a small battery to provide a buffer for those times when you accelerate and need a lot more than that. Plus the battery would get charged while the car is sitting in the lot, braking or idling too.

Well that is true for the most part but I want MOAR power. I want to drive up and down hills on cruise control for hours at a time

Ok yeah my car is a gas hog, crown vic.

You are technically correct for cruising on a flat road, but even the Chevy Volt has a 53 kw plant. I presume there is some reason for this excess...

$5300 for an engine in the volt configuration might not be economically impossible...

Actually I had written up on this idea a while ago. If you had a thermoelectric car you would not need a transmission (-300lb, $2000), heck of a lot less engine (-400lb -$2000), lots less car body steel and suspension (-300lb - $400), no need for an alternator (-$160), nor air conditioner compressor (these chips make great coolers too). Perhaps without having to haul around so much steel, you could make due with just 53 kilowatts and forget the batteries. My estimates are very rosy of course, but without all these support systems, and the simplicity of assembly, a thermoelectric car might be competitive if not roaringly competitive.

EDIT:
No need for external emissions controls either, put it right in the firebox. No muffler needed nor exhaust manifold. It would never break down in the usual sense although every year you will want to clean the firebox if you are using dirty fuels.

It would have pretty much every advantage of an electric car and none of the disadvantages. Not only that, but your car would be a real plugin in vehical! In fact, plug the car into the house and power your house with it! or plug it into 5 houses, you got enough power to do so.

ohiovr wrote: You are technically correct for cruising on a flat road, but even the Chevy Volt has a 53 kw plant. I presume there is some reason for this excess...

Yes, but it is using those 53 kW only a fraction of the time. Your engine can still bring 100 kW and your conventional battery (or capacitor) will deliver 100 kW of power to the engine for a few minutes at a time. The rest of the time, the engine will be running at a hand full of kW and the battery will get recharged by your nuclear battery during that time until you need to hit the "gas" hard again. Plus you get even more energy back when you brake or go downhill. So I really doubt that you would need more than 10 kW sustained from the nuclear battery. The conventional battery or capacitor will take care of the situations where you need more.

Heh I wasn't even thinking about using an Sr-90 power source. darn that'd be cool. Well thats one way to reduce the fission waste problem, use it to power our automobiles. What would the hippies think of that I wonder...

Now... you can even charge the battery when you are not using the car, which for the most part, is at least 80% of the time for most people... Might be possible to get away with a lot less power even still....

Things I don't understand in Hybrid world is why they don't use rotary (even rotary diesel), or augment the charging system with other means like solar, thermo, etc. Every watt counts.

I wanna hear more about the grapheme thermoelectrics. I'll go out looking, but if you've got any especially good links, I'm game.

The little gizmos I've been playing with are fun, but something that can take wood stove heat and be ... heck, we'd settle for 19% but if we can get 50+, hoorah ... well, the rules change.

Dr. Bussard had a piece of art in his office, evidently a going away present from co-workers. I believe EMC2 has it ... it was at the Santa Fe lab. It depicted him at a desk with two phones, one to each ear, smoking, and saying something impolitic to the effect of, "Well, if that's the case, maybe SOLAR is the answer."

One wonders if it was why he was leaving.

So ... if that's the case maybe thermoelectric is the answer.

Tom Ligon wrote:I wanna hear more about the grapheme thermoelectrics. I'll go out looking, but if you've got any especially good links, I'm game.

The little gizmos I've been playing with are fun, but something that can take wood stove heat and be ... heck, we'd settle for 19% but if we can get 50+, hoorah ... well, the rules change.

Dr. Bussard had a piece of art in his office, evidently a going away present from co-workers. I believe EMC2 has it ... it was at the Santa Fe lab. It depicted him at a desk with two phones, one to each ear, smoking, and saying something impolitic to the effect of, "Well, if that's the case, maybe SOLAR is the answer."

One wonders if it was why he was leaving.

So ... if that's the case maybe thermoelectric is the answer.

Thanks Tom, this is my pet topic

I've lost some of my more interesting links.. But here is one I remember that showed a zt of 3.25 at 800K, which is still only 27% efficient however the bulk material cost is almost nothing

http://www.nature.com/srep/2013/130206/ ... 01228.html

I recall reading about a zt of 20 discussed...

http://scitation.aip.org/content/aip/jo ... /1.2814080

Unfortunately both of these links are behind pay walls.. but scientists gotta eat too I guess...

This is a fairly good article (though outdated) and it is not behind a pay wall

http://www.intechopen.com/books/advance ... n-graphene

Well, heck, still all theoretical. All talk, no hardware.

What we need is a good high school student to collect all the school's pencil dust, run it thru a blender (no kidding ... with household materials and a blender, you can supposedly frag graphite into little bits of graphene), and build one.

To be really trendy, there should be a 3D printer involved to place all the little flakes of graphene just so.

Should be good for national honors in the Intel Science Talent Search.

Is anyone else getting really annoyed that this board is turning graphene into grapheme?

Tom Ligon wrote:Well, heck, still all theoretical. All talk, no hardware.

What we need is a good high school student to collect all the school's pencil dust, run it thru a blender (no kidding ... with household materials and a blender, you can supposedly frag graphite into little bits of graphene), and build one.

To be really trendy, there should be a 3D printer involved to place all the little flakes of graphene just so.

Should be good for national honors in the Intel Science Talent Search.

Is anyone else getting really annoyed that this board is turning graphene into grapheme?

Sorry about the grapheme, thats a different pet project of mine.

In case you were wondering if nano tech will ever have a future:

https://www.youtube.com/watch?v=7is6r6zXFDc

Since a grapheme is the smallest unit of a written language, and graphene is supposed to be an element in an especially efficient thermoelectric generator, maybe the board engine is trying to tell us to build TEGs and power them using the heat from all the talk in Washington?

Do phonemes produce phonons?

What do institutions created by Hamilton have to do with Hamiltonians?

This is all very curious.