Converting Room Temperature into Electrical Energy

Hi Shyam,

I'd prefer to use something a little less exotic like a Stirling engine. It works off a temperature differential. There's even a toy version that will operate off the heat of your palm or a cup of hot coffee! This isn't a perpetual motion machine and there are people who actually manufacture them. Just google "Stirling Engine". From you previous posts, however, I suspect you already know about this.

There are many ways you can use small temperature differences to generate power but you must remember there is one immutable law your thermal efficiency is limited by the temperature difference on the Kelvin scale.

For example if your hot source is 300°K and your cold sync is 270°K your maximum theoretical thermal efficiency would be 10% whereas in practice you would be lucky to get half that so you must expect the cost per KW of your generating plant to be very high

Various systems have been built one such pulled up cold water from the depths of the ocean and used the heat from the surface layers another used pools of hot salt water heated by the sun and evaporative cooling towers but it is only rarely that these schemes are economical

Correct syphrum, I was just taking shyam's invitation to jump in.

I've been thinking of using a Stirling engine where I'd put the hot chamber on the roof of the house and the cold chamber inside the house. This would drive a ventilating fan that would cool the house during the day. It's hot here for most of the year so the contribution of electric fans to my electric bill is substantial. They operate almost 24/7. It's not quite as exotic as shyam's suggestion but it's something I can try.

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I am sorry to say you are trying to create a type of perpetual motion machine.

The idea of obtaining a source heat from the roof is fine, but for the engine to function you must have a source of cold you cannot use the power generated by the Stirling engine to create the cold source!.

The best you could do would be to use some of the power generated to drive fans in a cooling tower such a you see on coal or nuclear power stations and bleed off some of the cooled air to cool the house

This URL has illustrations of commercial built power systems of this type

http://www.solarpond.utep.edu/

"I am sorry to say you are trying to create a type of perpetual motion machine"

Surely, with an external source of heat (the sun) it is no longer a perpetual motion machine?

My reference to perpetual motion was because you wished to use the room both as the cold sink for the stirling engine and use the power from the engine to cool it you cant have it both ways!.

any heat engine tries to heat up its cold sink, that is why power stations spend a lot of money building cooling towers , you increase the efficiency of heat engines by making the hot side hotter an the cold side cooler.

Look at the human body model.

It keeps itself at constant temperature. Yet there is energy source on demand. We are best quality battery.

Our system uses energy to store energy and to generate energy. We can work on similar model where natural IR at 300K will be enough energy to be used. However, the same will be much better if one starts at solar energy which has greater power density.

For me biological model is very interesting one. Look at any insect and you will find that they are of very high efficiency chemo-mechanical system with condensed chemo-energy buffer. Just look at the green leaves and their wondeful way to grow into tree.

What I am talking is not lots of energy but a bit or bits of energy to sustain from what we have naturally in abundance and not from what we can generate by consuming things. While trees also need something from earth, they give back all and make it much better over time. We all make it worst.

If you have to make a system to survive for say 100 years in nature on its own then what will be your choice. After all batteries can't keep for ever.

I am thinking to make the bacteria inside the electronics that can survive and can generate energy for the electronics taking small food, water, and air. I am not talking about ns electronics but something that can survive hundreds and thousands of years.

I read one statement of Madame Marie Curie that there are crystals that will store the radiation induced information in the material as defects and then on heating will give back it as light. Taking that as starting point I did my Ph.D. in thermoluminescence materials that can be of highest efficiency in that process. I could achieve it to great extent and it made me very happy that I took that starting point from the great Lady's thoughts. I met her grand daughter in one of the conference on same topic and it was my great pleasure to see her. I would have loved to see her grand mother as well. My son was born on her birth day the November 7. Hence, her stars are around me.

I feel great to think the way our brain manages energy and optimizes its computation, lots of communication, real time information acquisition, and action that beats the metal strength even with soft tissue that we all have.

Bio chemical world is the most wonderful one and one can easily say that we are going to be there for our future energy resources, robotic machine designs, machine brains, and lots of information storage media.

"It keeps itself at constant temperature. Yet there is energy source on demand. We are best quality battery."

Actually its more like a fuel cell than a battery. You take a fuel in the form of carbohydrates and combine it with oxygen to produce the energy you need to operate. There is no energy being generated from the background thermal energy in the air, quite the contrary actually. A human being needs considerable cooling since a rest it pumps out about 75 watts and can produce op to 700 watts for short bursts. This cooling is achieved by convection and evaporating water from the skin. Too much ambient energy in the atmosphere results in the cooling system failing and you end up with heat stroke. It only takes an ambient temperature of 37ºC with 100% relative humidity to start hyperthermia off.

Dear Masu

I thought that battery is a very general term and even an explosive packed energy is called battery in defence. Fuel cell perhaps is the right term as pointed by you. You have a very sharp eye.

There are many men in India who don't put on cloths and can live over 100 years. By protecting the body, most of us have made it useless. Have you ever known or come across that any Budhist monk has suffered stroke? I have seen a group of budhist monks drying out ice wet cloth placed on their body and I could visibly see the steam coming out. It was on national geographic channel. Those do yoga and control their minds thru brain can survive lot more difficult situations. I agree that we all have end of life and does not matter what we do to it to make it the best.

Living old and being part of the society was not Indian culture. People were supposed to leave home forever after they were 75+ and were to live in forest away from home. Some great people even decided to kill themselves after they achieved whatever was best possible from life. Among them were brothers of Rama and Pandavas. These are great characters from depicts of Ramayana, Mahabharata and Geeta. I wonder if old life really needs protection. I am yet to reach that in 20 years so may plan to exit on my own. In one custom in Africa where sons kill their elders sounded similar concept but a bit odd type. Looks to me that after wars many armies used to kill their winners as well. If they lived more then there was a chance that they may also face defeat and that may lose their fame. Look at the way some sports men / women retire early at their peak. What is there in their minds when they do so. Is this world worth living in rotten way for long counted out in days? My father told me that he wished to exit the life to join the new one and he died talking this to my brothers and sisters. He was 85 and died under controlled wish. Many in India do so. It is not known how they can do so.

"There are many men in India who don't put on cloths and can live over 100 years. By protecting the body, most of us have made it useless."

In Australia you will come across may people that do irreparable damage to their bodies by not wearing appropriate clothing. The UV levels in sunlight have always been high but with the hole in the ozone layer, yes is sometimes extends to parts of Australia, you can suffer from sun burn in a little as 10 minutes. Half of all Australians will need to have a melanoma removed during their lifetime. I remember a mad Scotsman that upon starting work in Australia insisted on working outdoors all day without a shirt. He called us all wimps for covering up whenever outdoors. His second and many subsequent days of employment were spent in hospital with first and second degree burns to 40% of his body. His skin never fully recovered and he ultimately needed cataracts removed from both eyes because even after this warning he refused to wear sun glasses.

The Australian sun is a real killer and to go outdoors without covering up is painful within minutes and ultimately fatal.

Perhaps anything done in short span may be dangerous. Most of the Indian people by now are highly radiation resistant. Skin cancer hear is hardly see. What I see in cancer hospitals in more due to eating dirty stuffs, dirty sex (Human Papilloma Virus or HPV) leading to cervix cancer in women, and brest cancer in aged women generally due to unused milk trapped for longer period, and some brain cancer. We do see some rare Non Hodgkin's Lymphoma in children and perhaps may be due to too much radioactivity deposited in Indian soil at places. We 1/4 of the world's Thorium deposit here.

I am from medical background and treat cancer in hospitals and I am WHO certified to do so. In Australia also you may find some race of human that can be radiation resistant.

As I have written earlier that desease and death is part of the life system and not to be hated. These were to weed out the likely non-resistance groups but today we protect them to infect the good seed of life is what we are working as negative to the otherwise way it existed. It will be ultimately epidemic and non-rewarding to people other than medical profession people who survive on just that.

If we can send our young men and women to die at the borders then can't we remove the old and the sick? Ethics are what we make and use.

The major problem is the high UV levels that we experience. First off is the damage to the ozone layer which increased the background UV levels. Secondly Australia is the second driest continent on the planet, second only to Antarctica. As a result we get very few cloudy days. Put the two together and you get a longer dose of more intense UV radiation which sends the rates of skin cancer through the roof. People that have higher melanin levels are in general less prone to developing melanoma but the trend is for every group to developing higher rates and there is no sign of it diminishing.

Australia is a relatively young country and for a fairly complex set of sociopolitical reasons the death rate is greater than the birth rate. You might think that this would mean that we didn't live very long but in fact on average we live till the ripe old age of 81. Put all this together and it means the only way we can stay in existence it immigration and Australia has drawn it population from every country on earth. Even with this incredibly diverse array of people there is an ever increasing rate of melanoma across the board.

It doesn't matter where you came from, if you hit people with enough UV radiation they will develop melanomas and the only answer it to minimize you exposure to unfiltered sunlight. For the most part people are taking precautions by wearing hats and avoiding exposure to direct sunlight when the sun is at it highest but it takes a long time for a melanoma to develop and its going to take a sustained effort to lick this problem.

What is the level of UV that you feel is high. Greater UV will generate greater Ozone so it must be self healing for the earth. Do you have any survey data on UV level? Usually UV from flash lamp is 10 times greater than what you get from sun as UV can't travel a lot of distance if it is greater than 5eV. Perhaps what you may have is lower than 5eV which can not be absorbed by the O2 or N2 molecules. Actually Ozone on earth is more dangerous as it kills the brain even at 100ppb level. Perhaps the Australia is a migrant society not from natural native, will have to take 1000-5000 years or more to get adjusted to this new place. You will have pigment cells after that period. For people of India it took 3000 years and our ancensors were clever to form a mixed race to carry the pigment of the locals in us. Some of us remain separated for long and still have that fare complexion but most of us now have lost that and are also not like the natives. Perhaps your people can also do that to invite some African race to get mixed to develop protection. This may not sound all that great but worked some time ago for us.

Radiation damage is also high when you have larger surface area and greater metabolism. In India people are poor and can't eat enough fat so they have less chance to get skin cancer. Young generation here now taking lots of beetle nut which is worst than smoking and many get cancer of mouth when they are below 30. I treated 300 cancer sick people each day and tried to educate people but things will be worst in coming years here as the number will grow 10 times very soon. I am planning to set up a very big cancer hospital for the same reason. People will need help. I expect to live 20 years so I have time to do something for them. If UV is the problem for you then you can use some kind of skin top which may also allow flow of air and may also look great. Let me think about it. If you need any help in electronics then perhaps I can do so and may even come to your place to help your people.

Hi Shyam, may I first wish you a happy new year. Yesterday you asked

"What is the level of UV that you feel is high. Greater UV will generate greater Ozone so it must be self healing for the earth. Do you have any survey data on UV level? Usually UV from flash lamp is 10 times greater than what you get from sun as UV can't travel a lot of distance if it is greater than 5eV. Perhaps what you may have is lower than 5eV which can not be absorbed by the O2 or N2 molecules."

Actually not only is there extensive data on UV levels but the Australian Bureau of Meteorology issues daily forecasts of the expected maximum UV levels for the entire continent on a chart like this

They also issue forecasts for the major population centers on a graph that shows the anticipated levels on a hourly basis like this.

The units are set out by the World Health Organization or something like that but they correspond to 25mwm^-2 of UV radiation. Basically it it's above 3 or 75mwm^-2 you need to take precautions. The following link will take you to the Australian Bureau of Meteorology site about UV monitoring and warnings.

You can follow the links to the rest of the ABoM site. It's a good site and they offer many services that come in very handy info. The live weather radar comes in very handy for checking if there is going to be rain in the near future. Dose the Indian equivalent of the ABoM have a similar service as I would be interested to compare the UV levels for India with Australia?

Dear Masu

Greetings for a very happy new year 2007.

Thanks for excellent information.

I am not sure if we have any such record in India. I did some experiments on solar UV 30 years ago and found that UV from 100W UV lamp was nearly 100,00 times than solar UV in 250nm zone. Hence, that makes to about 10mW/sq. cm. If I take UV spectrum up to 400nm then it sure it must be much higher number. I did this experiment in summer. My main aim was to study data lose on UV exposure in EPROM Chips. I used CaF2:Mn thermoluminescent crystals to measure the UV by phototranfer of stored traps in the radiation exposed material It was a bit complecated scheme and was my research area.

I will plan now to measure the UV in India at some places on regular bases to see what is existing here. Indians get cataract due to UV and get more crop growth due to UV. They do not get skin cancer. Cataract has latancy period of 5-years so there is no immediate effect and must be a very slow process. I am 56 today born on january 1, 1951 and do not use glasses. My father had cataract at the age of 80. He was a farmer. I often stay inside the building and work on computers for the last 35 years. Hence, my exposure to external UV may be relatively small. I keep too much busy with experiments so find no time in the day time to come out. I walk in the morning and evening.

Eugenics's is dangerous territory to venture on but there are two things I would like to comment on, our fellow primates seem to carry a virus similar to HIV to no ill effect presumably due to evolution allowing a better chance of breeding to the original sub group that had a natural immunity.

There exists a small sub group of humans with this immunity and I feel they should be encouraged to go forth and be fruitful.

I wonder if anti viral drugs that prolong the lives of HIV carriers is altogether a good thing I think great care should be taken the most humane way possible that they do not pass they infection on and that their anti virals should be withdrawn in extreme cases

I agree that forming a mix race will be ideal but not easy as people may be civilization apart. Correcting a gene by injecting coded or cleaved genes seems not working all that well. However, fusion of the basic cells sometimes works well and some time it does not work at all. Hindues by nature made a rule to mix at far links rather han close links and they realized that this helps in removing many problems. In fact they prohibited close relationship among families that were related before. If they knew this at that 3000 years ago then they must also had other types of knowledge. In epics of Mahabhata you can find that they could get birth from a dead man's body parts or tissue culture. Hence, those died without son or daughter were kept in some kind of oil for the purpose and once they could get the tissue culture completed, the body was disposed off. There is also discription of using some kind of aeroplane that used fire or fuel to drive it. I can't say if these were real or imaginary ideas but they had all these ideas for sure. Rejecting an adopted gene may be a serious mistake. It is more powerful than the rest and hence, if you wish to be stronger and effective in shorter time then mix up somehow by elivating the standards of the others and respecting their culture. It still make take 100 years. Our tribals are almost like all of us now except for only few of them. This was a great vision of the people who came here in early time. They were very very intelligent and could write books like Veda and could think like Geeta of Krishana. No literature tells to kill brother father and grand father but Geeta teaches just that. For an armyman no one is above the truth and you kill all those are against the truth including your own. Life wasn't given any greater value than the way of life to live it. I think finding solution of all at the place is a much better idea. Americans are now getting mixed with migrants. Indians abroad are also taking same decision so why not those are in AU? Help your natives to adopt your best and offer then everything for it to happen.

Funny to read that you work as a professional in heath care and write such funny conclusions. I learned from the past that those wealth diseases were also present but people didn't know about them.

What I know is that most cancer is popping up at higher age: It could well be that the average life of Indian people is to short to have the same amount of cancers as in Australia.

The clothing style is also different: Indian people have more clothing (long skirts,...) than Australian, who still go for the western style for when it is hot.

The relation between breast cancer and "trapped" milk is also strange: I know that there is a relation between milk and breast cancer: it seams that baby's prefer milk from a "healthy" breast, when they drink less from one side is it known that there is a chance that this "bad" tasting breast is developing cancer on higher age. Big chance that the cancer was already present but kept small by the immunity system for years.

Perhaps there are more reasons for the way people wear cloths in India. There are three distict 4 month long seasons. Too hot, too chilled and lots of rain. Mortality rate has been bad in India and that is one of the reason that women who lost their Child also did not care for their left over excessive milk. They never received any medical care in early time and even now it is not all that great. Cataract is from greater heat exposure as well as from UV. I agree that average life span is about 75 years now and is not very high enough to see the skin cancer of old age. I hardly have seen it in India in 100 year old either. Perhaps some people may not take skin problem that seriously and these cases may be hidden. This was so for the cancer in women as they did not like to expose their body to male doctors. Now perception is different in educated lot, but may still be very bad in uneducated villagers.

I am a trained Radiological Physicist and not a medical doctor. I am not doing any research in those areas. My area of research is nuclear radiation detector technology.

Melanoma is a particularly aggressive cancer and readily metastasizes. There is a distinct possibility that deaths are not being attributed to skin cancer because the actual cause of death was some other cancer. This was certainly the case in Australia some time back.

It's interesting that you quote the average life expectancy at 75 for India. I heard today that they have upgraded the mean life expectancy for a Australian from 81 to 83. I don't know exactly where that puts us compared to other countries but it must be near the top of the list

I've only read half the thread and am reminded of silly arguements with friends.

My point is that humans can develop genetic resistance to radiation, and if you hit them with enough radiation, they can still burn. Neither statement invalidates the other. To be really simple, obviously darker people are more immune to sunburn, let's say. Still, if they stay in the sun long enough, though much longer than a light skinned person, they can burn.

After half the thread (which is pretty long), we still seem to have people arguing that just because you can hit anybody with enough radiation, that genetic resistance doesn't exist, and people treating this like an actual arguement???

Dear Guest

Please do not change the title of the thread, which is the discussion area here.

You are right that radiation will cause damage to all but at different levels.

1. Less to dark people

2. Less to thin people

3. Less to dehydrated people

4. Less to men than women

Now that difference of less and more somatic damage is only at the bottom side where it matters. Genetic changes are slow process, happen in few people per year and then these are genetically spread over the population in many many years. For high radiation doses, it will have same effect on all people. Natural radiation dose in 1/80 factor down to permitted radiation level to radiation workers. Hence, the nature is kinder. Natural radiation level background in India is about 5uR/hour for ionizing radiation. Some hot spots are 200uR/hour which is of great concern to us. We have no data for UV. I am going to start with that now.

All evolution is through gene mutation or gene damage. In long run some of the species will be wiped out and some will stay to get mutated again. This goes on for ever. Harmosis or radiation helping health is not an acceptable thing. However in long run it may be true and by than it might have experienced the damage to itself and by weeding processes, only those can survive may be seen. Black race is weeded race, more stronger in natural disaster handling and should not be wiped out as was done earlier when people moved they killed the native. India became a multi culture and our ancesters knew that mixing with locals was borrowing a very strong gene generated over very long span of time. In fact the locals in return obtaned less resistant race. In out gene duplication we have tendency to keep all information and hence extra information does not go away easily.

Intially the gene is added and information is self duplicated in a loop. Then in next sequence becomes a part of the other gene. see the second picture.

Ah! Now I see why you thought it was a perpetual motion machine.

Actually, the thought of using the cooling effect to cool the cold chamber didn't occur to me. The stirling engine operates off the temperature differential between the roof and the inside of the house. The difference should be enough to get it running. The ventilating fan gets the air in the house moving, creating a cooling effect. Air in motion tends to cool the body without necessarily lowering the ambient air temperature.

If it does lower the temperature in the house, it wouldn't be very much, maybe a degree or less. Besides, once the temperature drops due to the approach of night or because of rain, the engine would probably stop since the temperature difference will get too low to sustain its operation so a perpetual motion machine it is not.

It's almost midnight here in the Philippines. I'd like to take this opportunity to greet everyone a Happy New Year! Mabuhay to you all!

For greater cooling, If you evaporate some water, then it will cool things much fater. Try by putting some wet cloth and then some dripping tank above that. If you have high moisture then it will not work.

The type K thermocouple produces about 40uV/C so if you serially link a million of them then you can get 40V/C. This you can achieve using MEM technique the way thermopiles are made. Perhaps making an organic thermocouple from grown up lipids will do that just like that by filling a tray with lipid membrane growing solution. I am not going to tell how one can get it made but there is a possibility of doing it.

I like the system of a thermocouple generated voltage.

Does it generate electrical energy from the heat?

What is the power/m² of contact surface?

The idea of cooling by transforming heat in electricity is excellent: put it in a cable and you can keep pipes cool, or a floor or ...

Now we just need the system to be developed ...

Try Peltier Cooling and heating. This works both ways. Thermocouple current can ve high and only voltage is small. Lots of them in series to be connected. It is only used for sensing now in furnace temperature, heat flux sensors and optical temperature sensors.

40uV/C into say 1 Ohms thermocouple will give only 1.6nW power/C. For 1000C it will be only 1.6uW. However if you have 1 million thermocouple layer then you will get 1600W/C power from same device. With 100C temperature difference you can get 160kW power.

www.peltier-info.com/

Hi Shyam, did you go into auto-write here? By my calculations, 40-uV/degC with a 1-Ohm thermocouple and a 1-Ohm (optimum) load would give 400pW/degC^2. The factor 4 difference in the number is due to internal loss in the thermocouple; but the important difference is the square-law relationship with temperature difference, which shows the efficiency increasing with temperature difference (as would be expected from any fundamentally-based thermal to ordered-energy converter). The Voltage is only linear over a limited range, but 100-degC difference would already give 4-uW. Even so, a million layers would have a million times the internal resistance, so 100-degrees and a million layers (of the original design of each layer) would only give 4-Watts.

Before piling too far into thermocouple generation, it's worth bearing in mind that the generating efficiency of thermocouples is considerably lower than the thermodynamic limit, because of both the limited electropotentials of real materials, and also the unfavourable relationship between thermal conductivity and electrical conductivity in thermocouple materials (high-conductivity metals such as copper and silver get near the fundamental limit for these conductivities, but aren't so good as thermocouple materials). The dual of this can be seen in the limited temperature difference that can be obtained with single-stage Peltier coolers.
Regards

Fyz

I agree that thermocouples are not for power generation and it is only thermo emf and not a thermo power. Thermocouples in thin layers will have very large resistance in K Ohms. At 1000C Type K thermocouple generates 40mV which itself is not much. Perhaps liquid to gas conversion will have much better energy transfer mechanism by volume and pressure difference.

We are drifting away,

PV cells transform radiation in electricity.

But they only work with shorter wavelengths, so useful in space and sunny areas.

The radiation that is emitted by objects at room temperature is way to long.

But PV cells don't need a cold zone to get that energy level difference. (attic - basement driven systems)

Peltier/Seebeck works with dT.

What I want is a process that can transform heat into electric energy without the need for a dT.

The 4h group in the periodic system has the semiconductors. Si is well known, Germanium is also used a lot and has a lower minimal temperature. Carbon is also usable, but only at high temperature. But what about Sn and Pb, are they usable as semiconductor?

Tin is a semimetal (i.e. the bands overlap, but there is a momentum mismatch). Wikipedia will help here. Lead is highly conductive already. The result in both cases is that absorbed photons are converted to heat.

BTW, there is no fundamental limitation that Carbon (diamond) can only be used at high temperature - unless you mean that it can only detect radiation from very hot objects.

In principle, you could obtain whatever bandgap you want using compound III-V semiconductors. You can also detect extremely sub-bandgap radiation using the quantum cascade process (based on alternating layers of different bandgaps.

But none of these techniques will over come the basic thermodynamic limits - the limits defined by the Carnot-cycle still apply.

Fyz

Think of atoms trapped in quatum cavity. This area is developing now. The trapped atom can hold on with energy for a while in excited state and each photon entering the cavity will accelerate the trapped atom like an engine and when enough energy is acquired, the lowest energy level electron will get out. There are some statistical processes of similar type at atomic level but can these be accelerated in quatum level? We all know beta emitters but do not know why they are acting in this way other than fitting a statistical number to the decay curve. This is a property of a system and not just like that. If we create similar system then you will find the same property with different exit rate for the electrons. We are at the starting point of understanding of the nuclear unstability in some materials and a long way to go. We can fabricate molecular structures and will find something highly useful. Bio material systems are best way to go. look at eel and many bio electric systems that work as per the wish of the animal. You can trigger to get the charge pulse.

"But PV cells don't need a cold zone to get that energy level difference. (attic - basement driven systems)"

Judging from your later comments, I suspect that your statement above may have intended to imply that photovoltaic cells violate the 2nd law of thermodynamics. If so, then this idea -- a common misconception -- needs to be challenged. First of all, PV cells work off of light (photons), not heat (translation/vibration/rotation of molecular-scale matter particles). So the concept of heat differential does not apply to PV cells.

Someone could object by pointing out that heat and light are interconvertable through the mechanism of blackbody radiation aborption/emission (and thus functionally equivalent). But if we analyze PV cells from that point of view, then a huge temperature difference is involved since PV cells (used at ambient temperature) convert sunlight that has a blackbody temperature of several thousands degrees. In other words, PV cells can convert sunlight to electricity only because their operating temperature is much lower than the temperature of their light source. If we allowed the PV cells to heat up to the temperature of the sun's surface (for example, on a probe in orbit around the sun, and assuming they don't melt), they would start to glow with the same spectrum and intensity as the sun, radiating as much energy as they absorb, therefore leaving nothing to convert to electricity (assuming the 1st law holds true). This analysis also explains the impossibility of making PV cells that convert ambient infra-red light (which is radiated by everything, even at night). It is possible to optically detect IR light, but either the detector must be cooled below room temperature, or the signal must be amplified by addition of outside electrical energy. People have tried make IR PV cells, and are still trying. I hope they succeed, but I wouldn't bet on it.

I don't mean to nit-pick, nor discourage attempts to get around the second law. But if you want to violate the 2nd law, it's a good idea to know where and how it applies. I myself have an interest in defeating the 2nd law.

"What I want is a process that can transform heat into electric energy without the need for a dT."

In other words, you want to violate the 2nd law. Be aware that this will not be easy. Anyone who succeeds desreves the Nobel Prize in Physics! No one has succeeded, and many have tried, for many years. Very interesting stuff. Worth trying, but good to know what others have already tried so as to avoid wasting time following refuted paths.

You write (again) about "(successfully) violating the 2nd law". If so, you need either:

To be clear that the Thomson formulation has been proved under QM assumptions, and recognise that it is only the other formulations that can be attacked (at least on any scale below galactic), or
To recognise that you are operating outside the bounds of the fundamentals of present-day physics - effectively, you would be assuming that the existing theories are wrong.

I don't believe that anyone would seriously argue that the present-day laws give a complete picture, or even that there will be some region or level where they break down. However, trying to work in these areas without guidance of - either a viable alternate theoretical structure, or a repeatable experimental result that violates the existing theories* - is pretty-much doomed to failure.

*I'm not aware of any such, but would be interested to be enlightened...

Fyz

"trying to work in these areas without guidance of - either a viable alternate theoretical structure, or a repeatable experimental result that violates the existing theories* - is pretty-much doomed to failure."

If I had a repeatable experimental result that violated the 2nd law, then I would have already succeeded in my quest! Of course proof in physics consists of reproduceable experimental (empirical) evidence. But do you really mean to say that no one should even bother trying to violate (or in other words, test) the 2nd law unless someone else has already succeeded? If so, then how will the initial successful result ever happen?

As for the need for an alternative theoretical model to replace/complete/fine-tune the 2nd law, the alternative description could be formulated *after* new experimental results indicate the need for it (assuming anyone finds any interesting results to report). Making experimental discoveries does not require that a theory already exist to explain them. Experiments are used to test new theories, but it seems to me that in most cases experiments also preceeded the new theories.

The scientific method requires that we understand all existing theories as tentative. No matter how solid they look now, new empirical evidence may show them to be incorrect or incomplete at some future date (as happened with classical mechanics, and as must happen with relativity and quantum mechanics since these two contradict each other). True scientists should always maintain some minimal level of skepticism about all theories (while at the same time not shunning whatever the best current theories happen to be). If we hold any theory as "beyond questioning", we sink into the reason-destroying realm of dogma and religion.

Of course I'm not suggesting that you shouldn't eventually try to violate the second law. But the critical word is eventually, and I advise at least the following cautions:

First, that you should not try to use the existing physical models to find a chink in the second law - at least in Thomsons elucidation - because, in so far as humans are capable of proving anything, Thomson's elucidation has been proved to be a consequence of present theories.

Then I am suggesting is that the possibility of violating it is unlikely to provide the first chink in the armour of present-day physics. If you get hung up on the second law, you will likely miss the first indications of the limitations in present-day physics understanding. My instinct being that, if it is ever to be done, it will be as a result of detailed work that at first site looked as if it was unrelated. (A good example in an unrelated field is perhaps the consequences of Andrew Wiles proof of Fermat's conjecture - the unravelling of all sorts of things in apparently diverse mathematical fields.)

My final note is that the second law has proved to be remarkably robust - I think I would be more surprised to see it founder (within the sub-galactic scale) than I would any other pillar of present-day physics.

Fyz

I don't think that transforming heat into electricity without a dT is a violation of the 2nd law. Nowhere I stated that I want a full transformation, the process will stop at a certain energy level.

There are basic processes known that do this. (Thermocouples) But the gain is low and the usability is even lower.

What PV cells do is catching a Photon, and using the energy of it to throw an electron over the junction. (very basic) The energy level that is needed is rather high and the efficacy is low. (no 100% as that would be a violation)

If you would take two identical PV cells, and irradiate them with the same spectrum and level you would notice that the cell will run colder if you allow it to drain its electric energy. (here might be the dT that you need to understand the process)

CCD does transform IR to electricity. The energy level is of course to low to drive the circuit.

The light that is used to read a CD (Attention CD!!!) is IR (approx 780nm), the photocell that is used to read out the data from the light is a kind of PV cell, but as we want the enlarge the sensitivity it is used as a Photo diode. (the signal needs to be above the noise level)

Serial linking of Thermocouples would not work at all: the combination effect would each time take away the difference. You need to go to a colder zone, (ice water) make the connections and go back in the hot zone.

Hi Gwen

I'll address your points in the order you presented...

Unfortunately, the fact is that transforming heat into electricity with zero temperature differential would be a violation of thermodynamics laws - including, but not restricted to, the second.

Thermocouples rely on dT. Like any other heat engine, the efficiency of operation (electricity-generated/heat-transferred) is theoretically restricted to the temperature differential (dT/Tmax), but practical thermocouples are at least a factor of two less efficient than this at small temperature differentials. PV cells have the at least the same constraints of course, but are even worse in practice; even when using sunlight they can only achieve 30% maximum; the reason for this lies at least partially in the initial conversion from light to photoelectrons, which ignores low-energy photons and dissipates any surplus photon energy as heat within the semiconductor.

Finally, thermopiles are serially linked electrically, but the junctions are alternately in hot and cold regions, so they do work. This would be what Shyam meant by his abbreviated "series" description.

Fyz

Here we come into another hot item: from where comes the potential difference in a thermocouple.

Some claim (to be in accordance with the 2nd law) that it comes from the zone where your cable cools down (the dT)

I think that it is just a natural effect: the heat is transformed in electrical energy over the junction, with a potential typical to the junction. this has lot to do with the chemical battery. there is also no dT but chemical energy is transformed into electric. (for high fliers fuel cell do function the same way), part of the energy is transformed into heat (the "price' to pay when you want to go from one energy faze to another)

But after all: the transformation is done at so low gain that thermocouples are useless. the systems functioning with a dT have far much better results.

PV cells do work quite well, when you irradiate them with the correct wavelength, all the rest can't play along and transferred into heat. It is like in sports, only those who fit in the window are accepted, the rest is rubbish.

The black body experiments show that you don't need a dT: the temperature level itself determines the amount of energy that is transformed from heat into radiation. there is no dT in the complete system, unless you tell me that each body radiates to the absolute minimum, what is again a way to cope with the limited capabilities of the human brain (on this point I agree with Mr Seaplane: only a small fraction of the humans is capable to understand the function of some basic things like Ohm's law)

It is this strange effect that makes radiation so difficult to understand: it radiates, no receiver needs to be in place or defined. It even radiates to a hotter body. Which at his turn gives his part of the radiation game. The final result will be that the colder will heat up and the hot cool down, you have to play the complete game (0th law)

Trying to deal with your notes in order:

Thermocouples, fuel cells, and batteries: I think you are referring to the junction potential (this has had several different names, so I may not be using the one you are most familiar with). Unfortunately (from your point of view) a circuit consists of several such junctions in series; if the junctions are at the same temperature, the sum of these series junction potentials is zero. Therefore, the only net output you can get from a series of such junctions is when there is another source of energy feeding one or more of the junctions. In a thermocouple, this source of energy is heat flow. In a battery or fuel cell it is stored chemical energy. In the former case, the efficiency of conversion is the standard dT/T, in the latter it can theoretically be very high. This is because the chemical energy is already "ordered", unlike the thermal energy.

Now to black-body radiation: If there is no dT in a closed system, the radiation will be at an equilibrium level corresponding to a black body at the same temperature, and the radiation leaving each object will on average be equal to that leaving it (the fluctuations away from average being purely random and so unusable for any purpose). The crux is that no net energy transference is taking place, and no thermal work can be extracted from this equilibrium situation without introducing objects at different temperatures. In the same vein, radiation to a hotter object from cooler objects is exceeded by radiation in the reverse direction* - it is only the net (the difference between the two) that has any chance of finding application, and even there we are back to the usual efficiency limits.

*And please don't start on Faraday isolators - they won't solve the problem, but the explanation requires diagrams and sums, which I'm not willing to go into here.

Fyz

You are again building up a closed system, assuming that all the radiation that leaves one body, will go to the other.

Then the second law is 100% correct.

But radiation does not play this game. It just leaves the body. so to look to radiation, you don't need a system to let it occur.

I agree with convection and conduction: it will only start when there is a dT. So if you want to do something based on conduction & convection: you need a dT.

I will not say that based on radiation you can cool a body to below the temperature of the receiver, no you have to play the full game, the result is the sum of all the energy flows. Nothing fancy that can be used to cheat on nature as this old lady takes you back from behind.

What I try to explain is that radiation has it's source in the atom itself and does transform heat into a higher level energy. A body will always radiate until it reaches the ultimate zero.

Perhaps at room temperature the energy is too small.

However at an elivated temperature we may find some greater use. Perhaps condensing solar rays on solar cells is a better process. In solar cells the temperaute plays negative effects as leakage increases. Hence, solar cells should not be heated and only light need to make the electrons to croos the junction.

We have a small project in which solar panel will be cooled by water bed and water will be drained out as warm water source. You can say a sink will be added to keep the solar panel in best possible functional state. To avoid contamination from water reaching the solar cells, we will use either Aluminum or SS316L as separator. This will also act as partial reflector.

Shyam,

I'm trying to do my normal work in between the responses but this thread discusses a technique to something my company would love to have.

The "dual use" solar panel is already done a lot, but I prefer to use air as cooling medium. Where I live we have to deal with below 0°C temperatures for half of the year. This makes water useless (unless you add additives, which makes the water itself problematic)

We make our living with heating cables, if it would be possible to make a wire that would transfer heat directly into electricity we would be able to make a cooling wire.

Add this to lines that should stay cold and you have an easy system that could bring food safety to the underdeveloped world or rural areas where a refrigerator can simply not work as it needs a fuel source. I'm not that interested in the energy that would be available from this process.

All the functional processes that have been passing the revue are based on electro-mechanical systems that need maintenance by qualified personnel and a lot of installation work.

From previous jobs I know that radiation is negligible as heat transfer mode at room temperature. Thermocouples have their equilibrium stage at about 0°C, makes them useless for our application range.

I'm wondering whether there are semiconductive combinations known that are useless at room temperature because the energy level is to high to be a normal junction. Normal semiconductors can be used up to a certain temperature, above this the semiconductor becomes a conductor and your powered circuit goes the the Walhalla of the IC.

My simple question brought up the discussion on the 2nd law. I'm not interested in breaking it but I think that a lot of us should try to understand it. For me it means that the amount of energy you can transform is always limited and you will always have waste next to it.

He, spell checker is telling me your name is wrong.

You say "thermocouples have their equilibrium stage at about 0°C". This is a traditional convenience when they are used for temperature measurement, as this as a temperature that used to be easy to maintain constant. These days, the zero-degree junction is more usually simulated via other electronic circuitry in any case.

In short, the 0°C "constraint" is not real, and would be irrelevant to electrical generation

Fyz

Thermocouple with one junction use other junction at room temperature which is a cold junction. As the device works on temperature difference within the limits of the operating temperature zone, you can change the room temperature and add this to your measurement using other methonds for the room temperature. Thermocouples are good for large temperature measurements.

Dear Gwen.Stouthuysen

In early days some 5000 years ago, people learnt to evaporate water to cool the stuffs. They made clay pots highly porous and water leaks slowly through walls. Others have learnt to wrap a wet cloth around a pot to cool in same way. This did not work in high humidity area and people who used the technology were from dry area.

You have suggested a very nice point here. The earth temperature remains nearly constant and if you circuilate water from ground to the walls and roofs then it will also be more like deep earth temperature. Build a water talk a large one above your house and pump the water to garden etc from there and not directly from pumps. this will make the house much better.

I take only fresh water bath and does not matter what is its temperature. It is winter here and water from earth is warm to about 18C from 80ft deep well. I can perhaps record the water temperature from below for an year to get some proper data. Temperature profile may change from place to place on how water is moving inside the earth and water table depth may also effect the temperature. We are at 212M from sea level and there are rocks around the place which cool or heat faster and have greater heat conduction rate.

"I don't think that transforming heat into electricity without a dT is a violation of the 2nd law."

"There are basic processes known that do this. (Thermocouples)"

Transforming heat into electricity without a temperature difference would most definitely violate the second law of thermodynamics. Lord Kelvin said this in one of the most common statements of the 2nd law:

"A transformation whose only final result is to convert heat, extracted from a source at constant temperature, into work, is impossible."

(note that the term "work" includes electrical energy, or any form of energy possessing a lower entropy than the heat source)

http://en.wikipedia.org/wiki/Second_law_of_thermodynamics

And thermocouples do rely on a thermal gradient. Do any of the physicists in this forum disagree with me?

http://en.wikipedia.org/wiki/Thermocouple

Hi Svengali

Thermocouple example is not the correct one as it worked purely on temperature difference. There is no thermocouple affect onless there is temperature difference among the two junctions.

Point here is heat energy and that makes things to happen.

If heat is not a Photon in Plank's radiation then his Nobel Prize will become useless. Heat energy with atoms is either Photons or kinetic energy, but in black body radiation it becomes free Photons.

There is life time of the processes that can collect energy from phonons and then can make a higher energy photon. On exit of electron the atom becomes ion on capture of free electron it emits the binding energy equivalent photon once again.

Also think of stimulated emission of radiation in LASER. Heat can keep pumping the levels from bottom to up and up and finally an electron exits the atom. We only have to find the right system. What is a hurry? My grand children or your great grand children will find it one day for their use.

I'm beginning to wonder if you are just being deliberately contentious.

If you use a thermal source to pump a laser, it needs to be at a higher temperature than the temperature of the lasing medium, otherwise reciprocity ensures that the lower levels are more densely occupied than the higher levels.

Fyz

Quantum dots do not work at Plasma temperature. Quantum devices are cool room temperature type. LASER was pointer to what we know and not what happens in quantum dots.

Nevertheless, this same reciprocity will affect quantum dots - and the operational limits are pretty-much equivalent.

Fyz

Think yourself in the sea of petrol sitting in a sub burning fuel all the time and making the CO2 to leave. You can keep doing this as long there is drop of oil in the sea. This is what I am saying about a sea full of energy at room temperature. If this is impossible with your thermodynamics then rewrite it.

I replied to your note 83 on quantum dots. I fail to see the connection - please elucidate.

Quantum dots are very poor thermal conduction points, they permits none of the three ways to let Phonon energy transmitted through their space. Even radiation is trapped like a black hole but process here is different. The phonon converted photon or external photon need to enter the quantum dot and then it is trapped for a very long period which allows multiphonon process to take place. Smaller the quantum dot, higher the energy of the enetry and exit photon. Exit Photons often oftained is of twice the energy. Hence, you need an array of them.

If you take the only thermal conduction as propogation of heat then what you say is right. I am not considering the thermal conduction at all. I am considering the radiation part here. However for other methods, thermal conversion by conduction is most likely processes and of greater advantage. only at high temperatures above 800C, we can think of radiation as very common power source where T^4 is helping the process.

Yes, I too was referring to radiation, and reciprocity and the thermodynamics laws are no different. Clearly, the fundamental efficiency limitations I was concerned about reduce as the proportionate temperature difference is increased - but this does not come into play when we are talking about "converting room temperature (differences) into electrical energy". I certainly wouldn't wish to invest in developing equipment to do this via radiation, as the returns per unit area are so low relative to using solar energy (even using the focussed image of the moon would give better returns...)

Regards

Fyz

Quantum dot photovoltaic cells are different type and can work from low energy photons. However, multiple types of such quantum dot arrays can only achive this as room temperature peak photon energy is too small due to near 10000nm emission peak. It will need more time to get the right device for this type of energy conversion but is very much in available technology resource now. Perhaps more nano material development will help in this direction and one day these material can be printed out in inkjet printers. What one needs is an array of nano cavity material embedded in optically transparent media. Think of C-60 balls in some adhessive. They are so small that they can be printed like ink. Cavities are only nm size and not a chamber for something. What we need to do is to creat a enegy pattern to hold the phons of low energy within the cavity to capture another photon of identical energy to multiply its energy on exit. It then enters another quantum dot to become four times the energy. Perhaps such three layers will push it to 1eV level to get an electron ejected to charge a capacitor which can charge a cell using charge transfer circuit even at low voltages.

It is possible to show this technology even now. In India, we get no financial support for the research and I burn my money all the time from hard earned over life. Hence, my research is much slower than my thinking for the same. You all have resources can easily try out and I will welcome it.

Air in motion, while cooling the [human] body actually raises the ambient air temperature - the energy removed from the body must go somewhere!

In fact - if the ambient air temperature is lower than the person's body temperature it will still cool the body - just slower. Convection will be caused by the air warmed by the body rising (being hotter than the surrounding air) - so the presence of a body warmer than the ambient air will actually cause the air to be in motion. (Note - there will also be a very small amount of radiant heat transfer - which heats air further from the body (it will also heat the walls of the room).

It is important to note that the motion of the air does not, in fact, cause the heat transfer other than by continuously supplying fresh cooler air to be warmed by the body.

When the air is at the same temperature as the body's core temperature convection and radiation cease to transfer energy. Whether the air moves or not will not cause (or allow) any heat transfer.

In this situation there is only one way that the body can continue to lose heat - by evaporative cooling. As with convective cooling, the movement of the air does not, itself, cause any cooling but simply accelerates it by supplying fresh air. With evaporative cooling moving air supplies air with a lower water vapor content, thus allowing continued water evaporation from the surface of the body. If the air were not moving then the only way water could continue to evaporate from the body would be as the water vapor dissipates away from the body.

As humans we notice the effects of moving air because of the continuous supply of new cool, low vapor content, air which allows a continuous heat transfer from our skin - which we notice as the feeling of being cooler / cold when the wind blows on us.

I am sorry to say you are trying to create a type of perpetual motion machine.

I assure you, syphrum, this is not a perpetual motion machine. People have been building them for about a hundred years now. They're not as powerful as internal combustion engines (which is why they never took hold) but for economy, they can't be beat. All I need is the difference between the temperature of the roof and the inside room and it would go. It won't work at night but that's okay. It's the daytime temperatures that I need to cool off not the night.

Have you considered that a Stirling Engine moves heat as it gains the energy from it? The cold end of the engine will radiate heat into the house. The important question then becomes whether the heat transferred into the house by the stirling engine is greater or less than the heat removed by the fan powered by it.

And the amount of heat removed depends on the temperature differential between the outside air drawn into the house and the air inside the house being removed by the fan.

Whatever is getting in need to be pumped out of the place to get the flow and that flow is the work done.

Think of a large pool of water with top of glass to allow vapor pressure to build to run a generator. This will work as an engine with solar power due to slow evaporation of water.

You can also focus greater amount of solar energy on water by different means. One way may be to run the water cooling pipes through roof and realing the hot water in the pool for getting more vapors, focussing light on the pool water and so on.

other way is to break the water bond by electrolysis and use the Hydrogen.

Depends on where I put the cold end. I could drive two fans and one of them blows the heat out of the house while the other blows outside air into the house.

Or I could position the cold end in front of the fan which blows air out of the house (blowing the heat out of the house also) and outside air comes in through the windows or doors to replace what went out.

I'll have to admit that this is all in my head and trying it out would mean a major modification to the roof of the house with no guarantee that it will be effective. I'm sure the engine will run but, will it be powerful enough to move a sufficient amount of air to cool the occupants? That I do not know.

Do you have clear Sky's at night ?, if so the engine could be run at night using the the installation on the roof to radiate away heat and the cellar that has been warmed during the day as the hot source (they used to make ice for ice cream in Bahgdad by freezing water at night in areas that had been shielded from the Sun during the day).

I can vouch for Kuwait and Australia being pretty cold at night.

Syhprum, you stated

"I can vouch for Kuwait and Australia being pretty cold at night."

May I enquire to where in Australia are you referring? Here is a map that shows the annual minimum temperatures for Australia in degrees Celsius

As you can see there is nowhere that has an average minimum temperature below zero. Yes this is the average minimum over the hole year but as you can see it really doesn't get that cold in Australia. Darwin for example has never recorded single digit temperatures.

For people like Seaplaneguy that deny that state that global warming is a hoax Australia has already warmed by 0.9ºC, so it's not as cold as when you were here by nearly a degree.

My impression of Australian nighttime temperatures are based on two December trips to Uluru on the first occasion I made a pre dawn trip dressed for the anticipated 40°C daytime temperature and really shivered.

On my second trip with my grandson also in December we encountered the lowest temperatures and heaviest rain for 20 years with a maximum 14°C through the day.

I am pretty certain Ice could be produced in a spot carefully shielded from the sun during the day and exposed to a clear sky at night.

I used to live in Adelaide and work in Darwin so I needed to fly back and forth with a stop in Alice Springs nearly every month. There were times that the temperature at 09:00 in the Alice was close to zero during the dry season but conversely a couple of months later the temperature was 39°C and rising rapidly. Yes it can get cold in the desert at night but its never the sort of sub zero temperatures that you see in North America and it can really cook during the day. The other thing, something that you are no doubt are aware of, is that nearly everybody lives in the eight capital cities and with exception of the national capital, Canberra they are on the coast.

The climate has already warmed by around 1°C and the current prediction is that within 30 years of so there will b no snowfall on the mainland. That could be disastrous as a large proportion of the snow melt feeds the Snowy Mountains Scheme, which uses it for power generation and irrigation. That means less arable farmland and more coal fired power stations. Things aren't looking good for us if global warming keeps on the way it is.

Why would coal fired power generation be selected surely nuclear would be a better choice as you abundent supplies of Uranium.

Is there opposition to nuclear power in Australia ?

There certainly is. There is only one nuclear reactor in Australia and that is a research reactor on the outskirts of Sydney. The current federal government is trying to push nuclear power but there is considerable opposition to the idea. The opposition is intense enough that if they keep pushing it I doubt they will be the government past the end of the year. We do have 40% of the worlds uranium reserves but there is a policy of their being only three operational mines and the ore can only be sold on the strict proviso that it must never be used for nuclear weapons. It's a complete wank really as all it means is they use our uranium for reactors and the stuff they would have used in reactors for weapons. There are however restrictions on who it goes to and places like India, Pakistan, Iran, North Korea and a host of others are not aloud to get any of our uranium. At least that's the idea. We also only export the ore, no enriching is carried out in Australia, which means we make stuff all out of it. There is talk about enriching it but for us to get the technology it is in breach of the anti proliferation treaties or something like that.

We also have huge coal, natural gas, iron ore, gold, silver, lead, copper, tin, zinc and just about anything else except oil that you get from the ground. Basically Australia is one gigantic mining operation. Since the coal is easy to mine in open cut operations nearly all the power comes from coal. They are working on a thing called clean coal technology that removes all the carbon and sulphur compounds from the exhaust but that is some time off yet. My personal belief is that thorium reactors are the way to go but only as an interim till fusion reactors are feasible. Uranium reactors are somewhat of a worry because of the waste. When they do the costing for nuclear plants they don't cost in the labor that will be involved in looking after the stuff till its safe. I did a rough calculation and the cost of looking after the waste and it works out at around half a trillion dollars per reactor and that's not factoring in inflation.

I would be surprised it they ever get a nuclear power plant off the ground in Australia but you never know.

Everyone worries about radio active waste but coal burning plants put far more radio activity into the the environment from the traces of uranium in the coal that ever nuclear plants do, and what is CO2 but dangerous waste.

I think France is the most sensible country with regards to nuclear power and we buy power from them via a cable.

Most of the worst radio active contamination has come from crash programs to develop weapons where little regard was paid to safety in the USA, USSR and the UK, where nuclear energy is developed in a sensible controlled way such as in Japan or Finland the waste problem is surmountable.

I think France has shipped their Plutonium to Japan. I wonder what those people will do with that. It is a terrible nuclear waste material. It is either used as fire cracker or neutron source to trigger the chain reaction in U238 in very small reactors. It may be more in use in nuclear subs due to very small core requirement. Many countries may like to do that as powering subs by other means is rather diffficult. I wonder if we can have portable reactors in trucks one day?

Pleas don't even joke about a nuclear powered truck. The only reason they ever stop to get some sleep is when the truck needs fuel or to load/unload. With a nuclear powered truck they would never stop. Can you imagine some drugged out zombie hurtling along the road in a 50 tone nuclear reactor? Eesch, the thought sends shivers down my spine. If they ever build a nuclear powered truck I'm off to find another plant to live on.

Dear Masu

All right, I am changing it from truck to train. I agree that the life of truck drivers is really bad.

We already have nuclear subs, space stations, so logical is something moving on earth as well. Think of nuclear train with megawatts of power in it. At some places we can even have conveyers of nuclear power. I agree that one good reason for nuclear power is no requirement to fuel the system for several years.

Serious consideration has been given to the design of nuclear locomotives and of course nuclear propulsion is already used for ice breakers, aircraft carriers and submarines

http://www.internationalsteam.co.uk/trains/newsteam/modern16.htm

A novel thought for trains: why not keep the nuclear power plant stationary and transmit the electrical energy via the rails and wires

There are many long rail lines where the electrical infrastructure is not in place and trains are hauled by diesel or coal fired locomotives

Whatever are bad of nuclear stuffs, we are not going back in time. It is power today and those don't want now may also ask for it one day. I agree that we need to use it in a safe way and should not creat massive disasters on earth. If U238 is not used in the reactors then it will go into tank shells. What is your better choice? I am waiting to have a fusion reactor car. I lived and worked in reactor environment for 22 years and found it very clean. I have also seen those smoke emitting thermal power and smelly gas power stations. It was sure a great thing at those nuclear sites. Perhaps few accidents world over pressed a panic button or perhaps nuclear explosive are much greater fear than nuclear power. Some people are also looking for control using this logic and disturbing the world. If you leave them, then they will also be like others. No one is better civilized here.

I doubt if 1000 people have died over the last 60 years due to nuclear power generation and use including the Ukraine mishap whereas 5000 Chinese coal miners are reported killed each year.

The large amount of radio activity emitted from coal burning stations may well be a substantial contributor to lung cancer deaths.

I have no ambition to own a nuclear powered car but I would welcome one powered by Hydrogen produced by a nuclear plant.

I lived in misty London before the War and well remember the health damaging effects of coal burning

Syhprum, you stated;

"I doubt if 1000 people have died over the last 60 years due to nuclear power generation and use including the Ukraine mishap whereas 5000 Chinese coal miners are reported killed each year"

Where did you get a figure like this. The death toll of workers that went into Chernobyl in an attempt to clean up the waste is conservatively reported at a minimum of 5,000. The total number of deaths varies widely and even the most conservative is 30,000. While it is unlikely that the 400,000 deaths claimed by some is realistic, it is not beyond possibility that 100,000 people have already died from the Chernobyl disaster. Have a read of these links

http://timworstall.typepad.com/timworstall/2004/04/chernobyl_death.html

http://www.greenpeace.org/international/news/chernobyl-deaths-180406

http://www.newscientist.com/channel/health/mg19025464.400.html

http://news.bbc.co.uk/1/hi/world/europe/722533.stm

The point is we have no idea how many people have already died, nor how many will in the future, from the radiation that was released into the atmosphere, as a result of the accident at the Chernobyl nuclear power plant. To make a statement that you doubt if 1,000 people have died is highly inaccurate at best and is more than likely a woeful underestimate.

The Chernobyl disaster is more than likely the worst industrial accident of all time and total death toll in the hundreds of thousands with millions injured would not surprise me at all. The final cost is going to be many trillions of dollars and it's the rest of the world, not Russia, that are footing the bill for the current clean up operation.

That's the problem with running nuclear power plants as a business. it only takes one money grabbing, short sighted company to cause a disaster like this. You can also bet that the people responsible will be no where to be found when it comes to proportioning blame and divvying up the cost for the clean up. It's you and me that end up paying the price in the end, not the bastards that cause the problems in the first place.

I will do a careful study of all available figures for the casualties in "The worst industrial accident of all time" and see how they compare with the sources you quote.

Have you figures casualties for any other nuclear power station accidents that come any where near those from coal, gas, oil or hydroelectric.

In India coal mine many times ended up killings hundreds of people inside the mine by filling water into the mine. Other deaths were due to toxic gas and sickness due to coal dust in lungs. This is a very dirt industry.

For Hydel power, there were dam burst killing thousands of people more than once. Hence, this is assured to have many more distaters.

Oil fires, often leads to the loss of property but rarely causes any death. These can be considered safe.

There were explosions in gas bottling plants and cylinders when explode, they go like a missiles to 10km area and it is a chain reaction with sure deaath for many but not exceeding hundreds.

Death in nuclear in India are rare and these have nothing to do with nuclear activities. In fact people here retire safely. Out of 200000 scientists / engineers, we never had more than 2 death per month (we had a family relief scheme for death so for every death they used to cut small money from my salary - hence every death was a record in the salary slip) and these were heart attack or other natural deaths and hospital deaths and nothing serious ever was noticed. In my 22 years work with 7000 scientists and engineers and that many casual workers, only 10 deaths were seen and some of these were due to human errors like some one hitting head to crain hook, jumping from construction hanger, standing in way of 10 tom automatic closing door white talking to some one, putting hand inside ss sheet press, putting wire into live and neutral for power mains, taking poison due to announce from girl friend, tsunami, cyclone hit, falling from car due to open car door, jumping from 3 story building for family reason etc. There was one death by bullet hit as some one tried to tresh pass the high security area and did not stop even on warning. Perhaps was a thief trying to steal something from nuclear plant. There was a death due to high voltage shock when engineer touched laser power supply HV capacitor. One death was excessive exposure to NH3 when a cylinder was left leaking and man went without any mask or oxygen.

I just had a quick look and the Bhopal chemical plant accident that killed an estimated 20,000 people is generally regarded as the worst single industrial accident.

http://www.democracynow.org/article.pl?sid=03/05/09/1421200

Compare this to the absolute minimum of 30,000 dead from Chernobyl's accident makes it at least 1.5 times as bad. Realistically however the Chernobyl death toll is more likely to be between 100,000 and 400,000 which makes it the worst accident by between 5 and 20 fold.

The problem with a nuclear accident is that the danger continues for thousands of years and the ultimate death toll may never been known till after the human race is extinct.

A huge problem with the waste from nuclear plants is that it needs to be constantly monitored. There have been some near disasters when spent fuel rods have started to overheat due to miss handling, equipment failures and over crowding of the current temporary storage facilities. Keep in mind to date all storage facilities for nuclear waste are temporary and have been for over half a century now.

I'm sure you have read "The Day of the Triffids" where mankind is confronted with a man made disaster triggered by not being able to keep one of his creations under control. What would happen if there was reoccurrence of something like the 1918 Spanish influenza pandemic? If a large proportion of the work force was incapacitated could we guarantee that safe operation of all the reactors and storage facilities? What happens if a terrorist caries out a successful attack on one of the many overloaded temporary waste storage facilities? Some of the possible outcomes send shivers down my spine.

Nuclear waste is super mega hyper dangerous stuff that needs constant attention, monitoring and absolute security. To think that we can bury and forget about it is guaranteed suicide. Till we can implement a solution to the waste problem uranium fission reactors will be a serious problem.

I am waffling again so I apologize. I plan to raise the nuclear power issue in detail in a few weeks time on my series of threads about Engineering an Answer to the Energy Question so I will stop and let others have a say.

I am interested it what you find about industrial accidents Syhprum so please post your findings. The figures could come in useful in the discussions I mentioned particularly if you can get some figures on the amount of radioactive waste from coal fired power stations as you mentioned earlier.

Yes, the Bhopal tragedy was a single largest WMD disaster caused by a small private industry keeping deadly poison in the city visinity and these people came from USA with all knowldege and equipments of safety they could have used but did nothing of that kind and killed so many. They should have been hanged million times for that but people of USA do not think so and they think Saddam did worst. Horrible LOGIC.

I have studied all your links and find only one that would invalidate my argument if it could be believed that from Greenpeace which is a well known biased source.

My estimate of deaths up to the present time is in no way invalidated although many sources quote larger figures for excess cancer deaths over the life time of people who have been exposed to radiation.

I think this Australian source gives the most balanced view

http://www.uic.com.au/nip14.htm

Comparison of accident statistics in primary energy production.

(Electricity generation accounts for about 40% of total primary energy).

Fuel

Immediate fatalities 1970-92

Who?

Normalised to deaths per TWy* electricity

Coal

6400

workers

342

Natural gas

1200

workers & public 85

Hydro

4000

public

883

Nuclear

31

workers

8

*This does not print out very well look to URL*

Chernobyl accident was simply in the waiting. Perhaps they looked at the technology in cheapest possible way and did not estimate the outcome. In India people have voice and it matters a great deal. Our new reactors are highly safety planned and we have more people at work than anywhere on earth. We have minimum 2000 engineers/scientists per reactor which is simply unaffordable for other countries. There are more than 30000 technical people in BARC. Most of the people are working on humanitarian research for the country and are think tank knowledge resource for the country. Demecracy is very strong in India and only when Government thinks that we should build a reactor, we can do so else keep generating drawing after drawing entire life and build nothing here till one day they retire packing for home. I became bit restless due to slow process so retired on my own 13 years ahead of retirement date. However, Government pays my salary siting at home doing whatever I like to do here. Wonderful. I love this Government and its laws. They took care of my mother, father, brother, sister, wife, three children and me. If I die then my wife will get the money till she lives. Hence, I do whatever small I can do for them and work on radiation safety devices and they pay for that also. Local engineering institute hire me as an expert advisor and pay me very high in money and respect. People in India care for scientists from atomic energy and they are never hated here. Most of the scientists are harmless creatures, fully satisfied from what they have.

Dear Masu

World dislikes people with nuclear power for fear of losing control over others and not otherwise. Some also fear that they may be discriminated if they don't join the voice. See what happens to France on not joining the WMD war. Right or wrong you are forced to follow else suffer is the clear voice. Some may get away and some may be hanged.

AU should go nuclear full throttle and can make the country green using that power. If middle east desert can be made green then why not AU and you will have no heat or UV. Ask for India to help you and I will come with them.

The thing that concerns me most about U²³⁵ fueled fission power reactors is the waste cores. To date there is no permanent storage facility anywhere in the world. There is only one reactor in Australia and that is a research reactor but there is no where to even store the waste from that. I believe they are keeping it on the reactor site in temporary storage. The government has been talking about a permanent storage facility since the reactor was built in the 60 but to date they haven't even gotten to the drawing board let alone developed a proposal for it. From what I read with the exception of the facility that is under construction it the USA the rest of the world has the same problem.

Humankind has been altering the environment and been a technical society for around 10,000 years. However, unless somebody comes up with a way to make this stuff safe we are going to need to store it for at least fifty times that long. The chances of us surviving as a species long enough to look after it is pretty slim and since it requires continuous monitoring and cooling to keep it safe that adds up to a serious problem some time in the future. We might not be around to see the mess but do we have the right to say stuff the planet, if we aren't here it doesn't matter?

India might have the population the guarantee continual monitoring but can you say that for every country that has nuclear waste than needs baby sitting for the next 500 millennia. We all live on the same rock and if the stock pile of used cores goes up in smoke in some tin pot banana republic we are all stuffed.

Indonesia is building a nuclear power plant not that far from Australia, but Indonesia is prone to earthquakes, volcanic eruptions and doesn't have the most stable political situation in the world. What happens if some lunatic like Pol Pot gets into power and decided to abandon all the technology? The reactor and its waste isn't going to go away just because some moronic, maniacal despot tries to turn the clock back 1,000 years. What happens if Indonesia gets hit with a, thought to be impossible and un-engineered for, earthquake like the one that caused the boxing day 2004 tsunami?

Personally I believe the way to go is fusion reactors in the long term and for the intevening period the Thorium reactors that use a separate neutron source to trigger and sustain the fission reaction.

If somebody however figured out a way to make the waste safe so that it no longer required any special handling procedures and couldn't be used as a weapon in any way then yes I would agree that it would be the way to go. Till then I just have too many reservations about the widespread use of the technology and subsequent generation of high level radioactive waste.

Reprocessing of nuclear waste is an alternative. Get as much possible out of it and use it for common sense in medical applications, education, industrial radiography. Some countries already may be sending nuclear waste into space away from earth (this is what one can esily do and not that I am suggesting to do). Using radiation for agriculture or agriculture products is another application. India will prefer reprocessing and minimum waste storage. Indians are very good at civil engineering and hence waaste storage may not be a problem. However, they will reprocess it as Indians do not like waste storage if they can avoid it.

I was wondering if UV can be used for some good purpose. It sure can increase plant growth. If you can grow lots of coconut and pine then you may have a great export potential. These trees can survive wind and need less water and more air moisture. They are less prone to forest fire. You can send ship loads of these to India as people here love this coconut as fruit as well as its oil.

Hi Shyam,

"I was wondering if UV can be used for some good purpose. It sure can increase plant growth. If you can grow lots of coconut and pine then you may have a great export potential. These trees can survive wind and need less water and more air moisture. They are less prone to forest fire. You can send ship loads of these to India as people here love this coconut as fruit as well as its oil."

It depends where you are in Australia. Like India Australia's size is fairly undistorted by the Mercator projection that is used to generate most of the maps we see of the world. In contrast North America and Europe to an even greater extent are relatively larger on the map than they are in reality. Just so I can upset all those Texans that think everything in Texas is the biggest I will give you an example. Texas covers a little over 600,000 square kilometers, New South Wales, the second smallest mainland state covers a little over 800,000 square kilometers. There was at one stage a cattle ranch that at its peak was larger tan Texas on its own. It has since been broken up but you get the idea, COMPARED WITH AUSTRALIA TEXAS IS TINY!.

Ok, I have finished upsetting good old Georg W red necked Bush so I will get back to what I was talking about. The tropic of Capricorn runs pretty much through the middle of the mainland so the northern half has a climate fairly similar to that of India with 3 months or so of torrential rain during the wet season and nine months of drought each year. The remainder of the mainland is what is best described as sub tropical so the rainfall is more evenly distributed over the year, but the bulk of the rain still falls during the warmer months. There are two tiny pockets of Mediterranean climate that gets is rain during winter, around Perth and Adelaide, but these are relatively small regions. Once you start moving inland it gets progressively dryer and by the time you get to Alice springs, which is 1,500 miles from the nearest coast, rain is a very rare occurrence.

Australian trees are a little different to the trees in the rest of the world as they are primarily eucalypts. Strangely enough you get eucalyptus oil form them and it is highly flammable. As a result bush fires in Australia are a very serious event. The native trees will literally explode if heated enough and this makes fighting bush fires a deadly pass time. The temperate regions of the country are currently experiencing the worst drought on record, some are claiming it's the worst drought in 1,000 years and it is possible that a drought like this has never happened during human habitation. Here is a picture that I found of the Darling river and posted in another thread. The darling river is about the same length as the Mississippi river in it has dried up, it's gone, kaput, it's just a collection of baked clay and mud puddles.

I am waffling again so I apologize, but getting back to your questions is we have serious problems with lack of water and man power. There are only 20 million Australians so any labor or water intensive farming is just not practical. We have such vast mineral deposits that its nearly always easier to dig a hole and sell the minerals than carry out some sort of farming. As a result the short sighted bean counting type people that control all the money make it very difficult to do anything that takes more than a couple of years to show a profit. It's a pity really and it's going to need to change and change soon if we are going to come to grips with global warming, but that's the way it is at the moment.

Dear Masu

I think Eucalypts should never be planted where water is a serious problem. It was planted in north and south India under world banks social forestry project and our people realized very fast and now they no longer use it.

Texas was not at all green when I went in 2002. It was warm and its airport was deserted type barren land. I went to Dalware and few more towns. There were hot winds and fig trees all I could see in the gardens.

Our farmers from Punjab and Haryana can easily transform your country if they are given a serious contract by the government. Thye will need only 5 years to change the country. However, if your country is being transformed with the knowledge of the government then who can help them? It may be worth sending a requiest to the government to ask India Government some kind of help. We did some time ago to Indonesia when their rice crop was fully deceased. India government sent rice with gene that could replace their entire crop and is free from problems and can survive under water.

In last 40 years our population trippled and our food production went 10 times higher. We now save food for 3 years for entire Indian population such that we can survive drout, flood and other disasters. In 10 years we will become 2 billions or near to that. We have scope to go another 4 times the food production and it is sure a serious worry for us as we can not feed 5 billion people in India 2050 We are so close to that population time bomb. If we can manage to educate people in 2020 then we can hold on to 2 billion strength and can stay on that. Our population does not consume large resources and reuses lots from packing cans to carry bags for many years. The new generation will be different so has to find way to reprocess things. The energy demand will be very high by the 20% population as the remaining 80% is based on agriculture self sirviving type. Now in 10 years, the ratio may come down to 30% - 70% as many from villages are in the process of becoming non-farming lot or engineers.

Water in Indian rivers is more of less stable and has not changed much except for its use which has become very high now. Drinking water is a serious problem now at many places as we are pulling out age old under water resource we had in the ground unused. It will put greater pressure in coming years as agriculture will spread to places where it was never before. I am scared of any sudden collapse of glaciers in north Himalayan zone and that may happen due to global warming. This will eliminate Pakistan from map of the world and part of India as well. This disaster is in the waiting and it just may happen in 50 years.

Certain people that are posting statements at CR4 claiming that global warming is a hoax worry me deeply. I must admit ten years ago I was skeptical about global warming but you only need to look at what's going on to see it's no myth. There needs to be a concerted world wide effort to combat the problem and that's the reason for my series of threads. The more we can open peoples minds to alternatives the better the chance of them being developed.

Something that I believe has merit is a distributed multi technology electricity generation system. The idea would be that every house would use whatever technology was most suitable for that locality. If everybody was connected to the grid then the excess power from one area and technology could be used to cover the deficit in another area. For example an area that is nearly always windy could cover areas that used solar energy at night and the reverse would work during periods of low wind. The question is how larger and diverse do you need to make the grid so that there is always enough power for everybody. It's sort of like the concept of not putting all your eggs in the same basket. It's also the sort of thing that can be implemented little bit by little bit and doesn't need some really fancy and expensive new technology that still needs to be developed. I havn't done the numbers but I have a gut feeling that it could be achieved with current buy off the shelf technology right now.

Problem in India is that Government sales the power at <US$0.1 per kW. By no means we can get closer to this using other alternatives as investment comes at high interest of 12%, government tax 14% and infrastructure cost. Easy way has been to store the energy in batteries and run them on power fail. I am doing this for the last 8 years and batteries are replaced at 2 years of use. We are not allowed to produce power and distribute it. It is the job of government here. We can sale power to the government at US$0.05 per kW.

Solar cells are 80% subsidized and yet that 20% can kiil the project. Wind not everywhere and is costal zone phenomenon. Cow dung waste was initiated long ago but tractors are replacing animals. My farm has not seen animal for last 30 years. My immediate concern is power storage and reuse as long as government can deliver even for 12 hours a day. I will prefer to put energy in other areas where I can get returns for many workers I may hire for the jobs.

Agro product optimization is crucial for India and other products are handicrafts and cloths for export. I am in engineering and that makes little sense here.

My vision for powerless devices is to make environmental sensors that can collect information for years without power. We already have such devices powered on Lithoum cells. This is a highly specilized area of technology which I will continue developing. This is a requirement and business sense here.

I love chemistry now as milligrams of substance is worth million dollar technology. I want more on chemical sensors now. IMS and few more areas I will sharpen the research pointers. Electronics is only applied ideas for me for my research and not a business.

You ar enot alone...

Here in Mexico is not allowed for commun citizens to produce energy.

This sort of short sightedness is why the solution to our ever increasing demand for energy is going to require, at least in part, a political solution.

Unlike as some have said in other threads the solution is not just an engineering problem. Without the intervention of governments around the World we will never be able to implement the many technologies that show potential.

The concept behind my An Engineer's Look at the Future of Energy blog. What I would hope is to be able to generate a paper that presents all the possible technologies that could be used with information on the advantages and disadvantages. Ultimately I would hope that the paper would be used to open the eyes of the powers to be on all the solutions rather than the blinkered outlook nearly every government throughout the world currently has.

There are pros and cons to the nuclear energy debate including the use of thorium as a fuel. The concept of nuclear energy will be brought up as a topic for discussion as a thread in my series about engineering a solution to the energy problem so I will leave it till then.

The next thread in the series will be posted on Sunday with a new thread every Sunday after that so stay tuned and practice your typing. The thread I used to generate the list turned out to be one of the longest threads for a while and even surpassed some of the Specs & Techs challenge questions in post numbers.

So keep all those arguments for nuclear power for now and watch for the threads each Sunday.

Dear Masu

Yes the thread on power sources is excellent one and you have done a very good work there. I must congratulate you on that. You may get few new ideas, but discussion always refines the way we think at things perhaps we already know but ignored.

British were dumping nuclear waste in AU so must be good reason for people to oppose the government as they can't be trusted for nuclear business. There looks little of other reasons.

By proper selection of refrigerant, you may be able to achive the energy transfer and can run the generator. This is similar to sea temperature difference energy so you can look for similar research. The boiling point of the refrigerant is critical here else you can alter it slightly using pressure difference.

Take a look here plenty of information about generating power from small temperature difference sources

http://www.solarpond.utep.edu/

Temperature gradient in salt water is known but that needs a lots of water.

Why do you use perpetual machine name here. There is endless source outside and also it is a sink due to its large mass compared to what your device is. Sin rays bring life on earth and partially earth sending back the heat in cosmos does not make earth a perpetual machine. My idea is to create small earth on earth or small device with external temperature source. Why all you try to place a perpetual machine idea. You have energy in the environment and simply think of consuming it using your own processes that can be started by this energy like bio reactor or something else. You have freedom to select, physical, chemical or biological processes to get things going. earth is just doing it for millions of years and we get lots of energy out of that each day to survive hear. Without sun, we will have nothing of that short on earth.