Well looking back through some old diaries I discovered that the Chernobyl accident was 20 years ago. According to official sites there are still around 400 UK farms that are unable to sell their produce due to the contamination from the accident. The number of deaths and injuries will never be known due to the secrecy of the former USSR. I am wondering did we learn anything from this accident. he government seems to want to build more nuclear power stations and the health and safety executive is looking at the implications of fast tracking the licensing of them. I personally feel that our taxes would be better spent on investigating the use of more renewable energy from the sun wind and wave power. The government recons the cost of decommissioning the existing nuclear power stations will be in excess of £70 Billion. Should we build more nuclear power stations given the past problems with safety and contamination.
chernobyl
Let me state before hand, I am a physics grad student who is very environmentally concerned. I know a little about power (because hey, that's one of the things we do). I'm not suggesting this as an opinion either. Nuclear power is a MUST. Here's why:
1) solar cells require harsh chemicals to produce, they degrade over time, and must be disposed of. if you are going to produce large amounts of solar cells, you must also come up with a solution for disposing of the large amounts of harmful chemical waste they produce upon disposal...and they are inefficient and very expensive. solar cells produce so little power, they could not even put a dent in the overall power consumption. to run one house, you would need a power cell the size of your roof. that would cost a couple hundred thousand dollars.
2) oil is a diminishing resource. one day oil WILL run out. it's a fact. we're using it faster than it renews. who know's when the world's oil will run out, but it will happen eventually. and as we all know, oil produces "greenhouse gases". i don't know whether global warming is actually occurring or not, but i think it's best to minimize our impact on the environment.
3) windmills don't produce a lot of power...certainly not enough to power a nation or even come close for that matter.
The important thing to keep in mind is that energy doesn't create itself! Any time you use energy, you take it from something else! A water turbine "steals" energy from the river. The water has to move slower because of it. No matter what way you take energy, it will have SOME environmental consequence. The key is to find that solution that does the least damage. Of course, the best thing to do is to reduce the amount of power you use.
Nuclear power holds so much promise, because there is so much energy wrapped up in single atoms. Yes, the environmental consequence is nuclear waste. Nuclear waste must be isolated from living creatures, but after a few decades it ceases to be radioactive. Furthermore, the amount of nuclear waste produce in volume compared to other power sources is very very minimal. Nuclear power plants do not harm the air quality. Only steam (water vapor) is released into the air.
Now, let me ask you this. How long has it been since Chernobyl? (20 years) And how many nuclear disasters have there been since then that you can think of? (0 for me) That's because chernobyl was a huge highlighter for the book on nuclear safety. To be honest, I doubt that we will ever experience a nuclear meltdown again. In fact, the nuclear scare is only damaging the environment more. Nuclear waste is re-usable in nuclear reactors; however, in the United States, government regulation prevents power plants from doing this. France has been re-using nuclear waste to power reactors for over a decade...problem-free I might add.
I don't think we should go crazy and build tons of nuclear power plants, but I think it's at least time that we get over this nuclear scare. Chernobyl did a LOT for the fast-tracking of nuclear safety.
1) solar cells require harsh chemicals to produce, they degrade over time, and must be disposed of. if you are going to produce large amounts of solar cells, you must also come up with a solution for disposing of the large amounts of harmful chemical waste they produce upon disposal...and they are inefficient and very expensive. solar cells produce so little power, they could not even put a dent in the overall power consumption. to run one house, you would need a power cell the size of your roof. that would cost a couple hundred thousand dollars.
2) oil is a diminishing resource. one day oil WILL run out. it's a fact. we're using it faster than it renews. who know's when the world's oil will run out, but it will happen eventually. and as we all know, oil produces "greenhouse gases". i don't know whether global warming is actually occurring or not, but i think it's best to minimize our impact on the environment.
3) windmills don't produce a lot of power...certainly not enough to power a nation or even come close for that matter.
The important thing to keep in mind is that energy doesn't create itself! Any time you use energy, you take it from something else! A water turbine "steals" energy from the river. The water has to move slower because of it. No matter what way you take energy, it will have SOME environmental consequence. The key is to find that solution that does the least damage. Of course, the best thing to do is to reduce the amount of power you use.
Nuclear power holds so much promise, because there is so much energy wrapped up in single atoms. Yes, the environmental consequence is nuclear waste. Nuclear waste must be isolated from living creatures, but after a few decades it ceases to be radioactive. Furthermore, the amount of nuclear waste produce in volume compared to other power sources is very very minimal. Nuclear power plants do not harm the air quality. Only steam (water vapor) is released into the air.
Now, let me ask you this. How long has it been since Chernobyl? (20 years) And how many nuclear disasters have there been since then that you can think of? (0 for me) That's because chernobyl was a huge highlighter for the book on nuclear safety. To be honest, I doubt that we will ever experience a nuclear meltdown again. In fact, the nuclear scare is only damaging the environment more. Nuclear waste is re-usable in nuclear reactors; however, in the United States, government regulation prevents power plants from doing this. France has been re-using nuclear waste to power reactors for over a decade...problem-free I might add.
I don't think we should go crazy and build tons of nuclear power plants, but I think it's at least time that we get over this nuclear scare. Chernobyl did a LOT for the fast-tracking of nuclear safety.
I thought that the new generation nuclear power plants made it literally impossible for another chenobyl to happen? I could be wrong but that was the impression I got... Australia will soon be looking to go Nuclear in atleast NSW which uses the most power due to Sydney 
My Geography teacher just tought me about this some hours ago ...
I don't know much but around 250,000 were injured because of Radiation...
I don't know much but around 250,000 were injured because of Radiation...
Look at this site and tell me you want more nuclear power plants
http://todayspictures.slate.com/inmotion/essay_chernobyl/
Radiation is ****** indestructible. When that shit gets into the atmosphere it can invisibly spread across a whole country and seep into food that gets shipped right to the grocery store you buy food from. And you'll eat it and you wont even know it- until you have a baby that is horribly deformed and you dont know why. I wish I still had the link to a site I saw once that listed all the 10000x% increases of cancers across the nation just from this one accident. And even ****** up new cancers and shit they dont even know what to call popping up everywhere.
http://todayspictures.slate.com/inmotion/essay_chernobyl/
Radiation is ****** indestructible. When that shit gets into the atmosphere it can invisibly spread across a whole country and seep into food that gets shipped right to the grocery store you buy food from. And you'll eat it and you wont even know it- until you have a baby that is horribly deformed and you dont know why. I wish I still had the link to a site I saw once that listed all the 10000x% increases of cancers across the nation just from this one accident. And even ****** up new cancers and shit they dont even know what to call popping up everywhere.
I want more nuclear power plants... more people die from car crashes than have ever died from nuclear related disasters, should we stop production of cars? infact more people have probably died from plane crashes then nuclear power plants.
Despite all this AFAIK the new age generators cannot have the meltdown chenobyl did thus nullifying that entire "essay".
Despite all this AFAIK the new age generators cannot have the meltdown chenobyl did thus nullifying that entire "essay".
| the1991 wrote: |
| Let me state before hand, I am a physics grad student who is very environmentally concerned. I know a little about power (because hey, that's one of the things we do). I'm not suggesting this as an opinion either. Nuclear power is a MUST. Here's why:
1) solar cells require harsh chemicals to produce...and they are inefficient and very expensive. solar cells produce so little power.... to run one house, you would need a power cell the size of your roof. that would cost a couple hundred thousand dollars. 2) oil is a diminishing resource. one day oil WILL run out |
Just to address a couple of points. Don't you think that cost and efficencies of solar cells will improve? If today a roof sized unit would work (and I've seen them in AZ), it doesn't seem like a stretch to extrapolate a more efficient system in the future. And as more are sold, manufacturing costs go down.
Oil? You are right, it's going. But what about renewable grain based fuels? Hydro? And I haven't read it yet but I saw a yahoo article about making petoleum out of plankton (no faith in that, but interesting thought).
I'm not anti-nuclear, I just think there are lots of options in the near and the distant future. All should be explored.
I have a couple of comments for a number of people. First, if we want to survive a severe power crunch which will eventually hit our country, we need to invest heavily in nuclear power. To date there is a number of companies which takes the waste of used nuclear fuel and recycles it by extracting out the usable isotopes of uranium. This is further processed to blend the high enriched uranium (HEU) with low enriched uranium (LEU), which can be used in modern reactors. As for the by-products like one member posted, the radioactivity of these elements typically have a half-life of few years, and a total radioactive life of 2 or 3 decades. This means that after 20 to 30 years these radioactive isotopes will decay into a non-radioactive isotope, typically lead.
Second, Chernobyl is not the only nuclear accident in the world. The US experienced a nuclear criticality in 1979. A criticality is an uncontrolled nuclear chain reaction were atoms are split exponentially, essentially a nuclear meltdown. Our experience at Three-Mile Island, PA was not as severe as Chernobyl. Three-Mile Islands criticality was stopped before a full meltdown could occur. Because of this, the reactor has been closed and sealed off from everyone because the radioactivity is so high that it poses a serious health risk to people. One should not get uneasy about this, because it poses no threat to the public or the workers at Three Mile.
Finally, one member was concerned with radiation getting into the food chain. Most people don't realize that we consume radiation everyday in our diets and we are exposed to radiation coming from the earth. If anyone has ever eaten a banana, they have comsumed a radioactive isotope of potassium-40. Also, we ingest carbon-14 in almost everything we eat that is organic. Finally, we are all exposed to a nuisance gas called radon that is found in many american homes. Radon is a leading cause of lung cancer in the US, so we need to be mindful of how long we stay in our basements.
To conclude, nuclear power plants are not the cause of a problem, they are the solution to an upcoming crisis that the US will experience unless we begin planning now. Citizens should not be afraid of the radiation risk or exposure involved, because we get more dose from food, medicine, and terrestrial sources than we do from power plants. With the addition of power plants, more high paying jobs will be introduced into the US economy. We must read and understand all aspects of nuclear power before we voice our opinions, and we must consider the tragic outcome if we do nothing.
Second, Chernobyl is not the only nuclear accident in the world. The US experienced a nuclear criticality in 1979. A criticality is an uncontrolled nuclear chain reaction were atoms are split exponentially, essentially a nuclear meltdown. Our experience at Three-Mile Island, PA was not as severe as Chernobyl. Three-Mile Islands criticality was stopped before a full meltdown could occur. Because of this, the reactor has been closed and sealed off from everyone because the radioactivity is so high that it poses a serious health risk to people. One should not get uneasy about this, because it poses no threat to the public or the workers at Three Mile.
Finally, one member was concerned with radiation getting into the food chain. Most people don't realize that we consume radiation everyday in our diets and we are exposed to radiation coming from the earth. If anyone has ever eaten a banana, they have comsumed a radioactive isotope of potassium-40. Also, we ingest carbon-14 in almost everything we eat that is organic. Finally, we are all exposed to a nuisance gas called radon that is found in many american homes. Radon is a leading cause of lung cancer in the US, so we need to be mindful of how long we stay in our basements.
To conclude, nuclear power plants are not the cause of a problem, they are the solution to an upcoming crisis that the US will experience unless we begin planning now. Citizens should not be afraid of the radiation risk or exposure involved, because we get more dose from food, medicine, and terrestrial sources than we do from power plants. With the addition of power plants, more high paying jobs will be introduced into the US economy. We must read and understand all aspects of nuclear power before we voice our opinions, and we must consider the tragic outcome if we do nothing.
| aacronite wrote: |
| Well looking back through some old diaries I discovered that the Chernobyl accident was 20 years ago. |
The remainders of the reactor is still sending radiation and of what i heard that will be during for a very long time.
Maybe a few hunderd years or more is possible.
| sgtlittle wrote: |
| To date there is a number of companies which takes the waste of used nuclear fuel and recycles it by extracting out the usable isotopes of uranium. This is further processed to blend the high enriched uranium (HEU) with low enriched uranium (LEU), which can be used in modern reactors. As for the by-products like one member posted, the radioactivity of these elements typically have a half-life of few years, and a total radioactive life of 2 or 3 decades. This means that after 20 to 30 years these radioactive isotopes will decay into a non-radioactive isotope, typically lead. |
Could you give a reference for this? A quick search only showed me that we are still dumping the waste at yucca mountain and this blurb from a nuclear management company. NMC link
| Quote: |
| Recycling used nuclear fuel in the United States
When most U.S. nuclear plants were built, the industry—with federal government encouragement—planned to recycle used nuclear fuel. In 1979, President Carter, completing a process begun by President Ford, banned commercial used nuclear fuel reprocessing in order to address concerns raised about the possible proliferation of nuclear weapons. This decision mandated a once-through, single use fuel cycle. Although President Reagan lifted the reprocessing ban in 1981, non-proliferation concerns continue to guide U.S. policy. Reprocessing and recycling are also not currently cost-effective in the United States, although recycling is being done in other countries. |
Sgtlittle wrote;
This is totally incorrect.
Criticality in a nuclear reactor is a good thing.
During a reactor startup, as control rods are withdrawn, the neutron population will increase thru sub-critical multiplication.
Criticality is the point defined as count rates increasing with a stable posative period without any further rod withdrawls.
At the moment of criticality Rx power will only increase for a very short time,
then for various reasons like moderator temp and fission poison production inside the fuel
will cause the Rx to go subcritical again and tend to shut it's self down again.
After you have a Rx critical you have to keep pulling the control rods out slowly to get power on up into the heating and power range.
As you increase a Rx's power output, it will actually be super-crictical, producing more neutrons than needed to be self-sustaining.
A CRITICAL reactor is at a self sustaining neutron population.
A prompt-critical reactor is a bad thing.
Fission produces neutrons immediately as a direct fission byproduct called prompt-neutrons, and delayed neutrons that are the daughters of the decaying initial fission by-products.
Reactors are controlled by maintaining the population of these delayed neutrons.
Nuclear bombs produce so many prompt neutrons the delayed neutrons are inconsequential. They are called a prompt-critical reaction.
External damage in nuclear accidents is caused by steam explosions.
A rapid depressurization of a hot pressurized liquid that causes structural damage. Further damage is caused by the release and ignition of Hydrogen gas.
TMI did have a partial meltdown. About 10% of its fuel melted into a glob in the bottom of it's reactor cavity. It's fuel damage occurred from overheating the fuel itself (~2000 degrees F).
Chernobyl is a strange type of Reactor.
It is called an 'N' type reactor.
It has fuel channels that run horizontally,
they get continously refueled while still in service.
Fuel is loaded into one end of these tubes,
and the spent fuel falls out the other end into a spent fuel pool.
There are very few N Reactors in the US, and they all have steel and concrete containment systems around them which Chernobyl did not.
The Chernobyl accident was a stupid a experiment gone bad.
They wanted to measure and quantify how much electricity they could generate from the inertia of a spinning generator after a turbine trip.
It usually takes a couple of hours for a commercial generator to come to rest after a turbine trip.
To do this they had to defeate several layers of redundant automatic reactor shutdown systems.
The sad part was that nobody in their organization ever stood up and
said 'hey, this is a stupid test Comrade'.
Did you realize that most major Universities have a test nuclear reactor right in the middle of town, on campus. These are called 'trigger' reactors because they use compressed air to 'puff' the rods out momentarily.
| Quote: |
| The US experienced a nuclear criticality in 1979. A criticality is an uncontrolled nuclear chain reaction were atoms are split exponentially, essentially a nuclear meltdown. Our experience at Three-Mile Island, PA was not as severe as Chernobyl. Three-Mile Islands criticality was stopped before a full meltdown could occur. |
This is totally incorrect.
Criticality in a nuclear reactor is a good thing.
During a reactor startup, as control rods are withdrawn, the neutron population will increase thru sub-critical multiplication.
Criticality is the point defined as count rates increasing with a stable posative period without any further rod withdrawls.
At the moment of criticality Rx power will only increase for a very short time,
then for various reasons like moderator temp and fission poison production inside the fuel
will cause the Rx to go subcritical again and tend to shut it's self down again.
After you have a Rx critical you have to keep pulling the control rods out slowly to get power on up into the heating and power range.
As you increase a Rx's power output, it will actually be super-crictical, producing more neutrons than needed to be self-sustaining.
A CRITICAL reactor is at a self sustaining neutron population.
A prompt-critical reactor is a bad thing.
Fission produces neutrons immediately as a direct fission byproduct called prompt-neutrons, and delayed neutrons that are the daughters of the decaying initial fission by-products.
Reactors are controlled by maintaining the population of these delayed neutrons.
Nuclear bombs produce so many prompt neutrons the delayed neutrons are inconsequential. They are called a prompt-critical reaction.
External damage in nuclear accidents is caused by steam explosions.
A rapid depressurization of a hot pressurized liquid that causes structural damage. Further damage is caused by the release and ignition of Hydrogen gas.
TMI did have a partial meltdown. About 10% of its fuel melted into a glob in the bottom of it's reactor cavity. It's fuel damage occurred from overheating the fuel itself (~2000 degrees F).
Chernobyl is a strange type of Reactor.
It is called an 'N' type reactor.
It has fuel channels that run horizontally,
they get continously refueled while still in service.
Fuel is loaded into one end of these tubes,
and the spent fuel falls out the other end into a spent fuel pool.
There are very few N Reactors in the US, and they all have steel and concrete containment systems around them which Chernobyl did not.
The Chernobyl accident was a stupid a experiment gone bad.
They wanted to measure and quantify how much electricity they could generate from the inertia of a spinning generator after a turbine trip.
It usually takes a couple of hours for a commercial generator to come to rest after a turbine trip.
To do this they had to defeate several layers of redundant automatic reactor shutdown systems.
The sad part was that nobody in their organization ever stood up and
said 'hey, this is a stupid test Comrade'.
Did you realize that most major Universities have a test nuclear reactor right in the middle of town, on campus. These are called 'trigger' reactors because they use compressed air to 'puff' the rods out momentarily.
| HoboPelican wrote: | ||||
Could you give a reference for this? A quick search only showed me that we are still dumping the waste at yucca mountain and this blurb from a nuclear management company. NMC link
|
I too would be interested in the background to the "2 to 3 decades" statement.
All i hear on the news when it comes to nuclear energy is that we need to find a way to safely store the (high grade) nuclear waste, and that we need to store it for a couple of hundred THOUSANDS years.
Quite a difference to "2 to 3 decades", don't you think?
it was freaky looking over the chynoble site on google earth you can see rusted half sunk cargo ships and alsorts, also did u know that some people still live there
| djcaution wrote: |
| Look at this site and tell me you want more nuclear power plants
http://todayspictures.slate.com/inmotion/essay_chernobyl/ |
/looks
I still want more nuclear power plants.
The initial question for me was what did you learn from Chernobyl.
Heres what I did not know until I read the post:
That 400 farms in England cannot sell produce.
Heres something I learnt back in '87'
I was driving a small van round Kent in the South East of England, doing my first job after having come out of the services.
I'd listened with interest to the NEWS and the maps showing where the fallout was coming.
There was a measurable amount of hiding the details from the public I realised after having travelled down one obscure country lane and spotting a "crew" of people taking radiation readings on hedges bordering farm fields.
There was nothing about this in the news. Your "400" fact is very interesting.
I have been out of England for 5 or 6 years so I wonder what my RAD reading is? 
Heres what I did not know until I read the post:
That 400 farms in England cannot sell produce.
Heres something I learnt back in '87'
I was driving a small van round Kent in the South East of England, doing my first job after having come out of the services.
I'd listened with interest to the NEWS and the maps showing where the fallout was coming.
There was a measurable amount of hiding the details from the public I realised after having travelled down one obscure country lane and spotting a "crew" of people taking radiation readings on hedges bordering farm fields.
There was nothing about this in the news. Your "400" fact is very interesting.
I have been out of England for 5 or 6 years so I wonder what my RAD reading is? Nuclear power plants contribute much less to global warming and aren't expensive in the long run, so there's definitely BIG benefits to them. Modern nuclear power plants are actually quite safe (unlike Chernobyl), so I don't think something terrible like that will happen again and support the building of new nuclear power plants.
| nilsmo wrote: |
| Modern nuclear power plants are actually quite safe (unlike Chernobyl), so I don't think something terrible like that will happen again and support the building of new nuclear power plants. |
Exactly! What went wrong in Chernobyl is avoided in modern plants by automated shutoff systems. The problem there was that control bars had to be raised into the reactor. When that failed, it went out of control. Modern reactors have bars that lower into them, in such a way that if everything fails (or any of the important warning lights go on), they fall into it and shut the reaction down with no external help at all.
The waste products from it, if handled properly, are no danger. And if stored properly, they don't harm the environment.
Personally, I would be much more worried about the possible outcome of a nuclear sub crashing than of a modern nuclear power plant melting down.
I am Romanian from Moldavia part... not so far from Cernobyl... From 1986 to 1990 we were taking pills at school. Every day they gave us some small white pills (very sweet actually)...
We were kids, we didn't know anything about this disaster...
I am 30 and I feel good.
I don't have any ill friends, I know ONLY ONE CASE of mutation - a child was born without fingers - and I still don't know if this were because Cernobyl or because of the mother...
My uncle was in a special nuclear commission, in Romania. If you don't know, we have one nuclear plant with 4 reactors, one of them was active since I don't know, the other one was started this year...
Romania use a Canadian plant model, in Cernobyl and Bulgaria are Russian models. Because we are in EU now, there are new safety measures. Our Canadian plant is working, Bulgarian have to shot it down... France have, I think, 40% of their energy made in nuclear plants.
Nuclear energy is good if all the safety measures are respected... that's it. Russian did something wrong, all Europe and all world learned something about safety... The engineers became "scared" and I bet there were special controls anywhere in the world...
BBC or Discovery (i don't know) made a special documentary about Cernobyl... very interesting really.
My opinion: it will be almost impossible for mankind to survive without nuclear energy... we consuming too much!! This 74 years old uncle told me a lot of facts about producing energy...
Question: what to you prefer: nuclear energy or burning coil for energy.
This wind and waves energy is... just to power houses... but how you will power THE BIG CONSUMERS as steel factories, concrete factories, cars factories??
We were kids, we didn't know anything about this disaster...
I am 30 and I feel good.
I don't have any ill friends, I know ONLY ONE CASE of mutation - a child was born without fingers - and I still don't know if this were because Cernobyl or because of the mother...
My uncle was in a special nuclear commission, in Romania. If you don't know, we have one nuclear plant with 4 reactors, one of them was active since I don't know, the other one was started this year...
Romania use a Canadian plant model, in Cernobyl and Bulgaria are Russian models. Because we are in EU now, there are new safety measures. Our Canadian plant is working, Bulgarian have to shot it down... France have, I think, 40% of their energy made in nuclear plants.
Nuclear energy is good if all the safety measures are respected... that's it. Russian did something wrong, all Europe and all world learned something about safety... The engineers became "scared" and I bet there were special controls anywhere in the world...
BBC or Discovery (i don't know) made a special documentary about Cernobyl... very interesting really.
My opinion: it will be almost impossible for mankind to survive without nuclear energy... we consuming too much!! This 74 years old uncle told me a lot of facts about producing energy...
Question: what to you prefer: nuclear energy or burning coil for energy.
This wind and waves energy is... just to power houses... but how you will power THE BIG CONSUMERS as steel factories, concrete factories, cars factories??
| HoboPelican wrote: |
| Oil? You are right, it's going. But what about renewable grain based fuels? Hydro? |
| Arnie wrote: | ||
|
Probably off-topic but the BMW claim is, "Powered by hydrogen, cracked from water, by sunlight."
http://www.autobloggreen.com/2006/09/12/bmw-officially-announces-the-bmw-hydrogen-7/
http://www.spiegel.de/international/spiegel/0,1518,448648,00.html
too.
Photolysis of water is possible, producing protons, electrons and oxygen. (The electrons can be used to reduce the protons to hydrogen gas.) But I'm not sure it's efficient enough, we probably have better chances finding some energy source (such as fusion) and obtaining hydrogen by electrolysis. So even their statement "cracked from water by sunlight" is misleading. As if all the used hydrogen is made like that.
Besides, cracking? Do I spot a freudian slip by a petrochem BMW guy obsessed with alkanes?
Besides, cracking? Do I spot a freudian slip by a petrochem BMW guy obsessed with alkanes?
| Arnie wrote: |
| Photolysis of water is possible, producing protons, electrons and oxygen. (The electrons can be used to reduce the protons to hydrogen gas.) But I'm not sure it's efficient enough, we probably have better chances finding some energy source (such as fusion) and obtaining hydrogen by electrolysis. So even their statement "cracked from water by sunlight" is misleading. As if all the used hydrogen is made like that.
Besides, cracking? Do I spot a freudian slip by a petrochem BMW guy obsessed with alkanes? |
But it is both possible and feasible. And Sol wont pop for a while yet - unless the chaos strikes at system-level too.
It's also possible to generate energy by making your pets run on a treadmill instead of walk around your house, but that doesn't make it a good solution to the energy problem.
Ever tried to photolyse water?
Ever tried to photolyse water?
Is there a promble?
http://www.nature.com/nature/journal/v238/n5358/abs/238037a0.html
http://www.nature.com/nature/journal/v238/n5358/abs/238037a0.html
Have you read that article or are you just presenting a Google hit? There indeed is a problem and even the summary of that article hints at it.
mea culpa. i don't have a current subscription but it is an old article, from 2001 it seems, so it should be available more widely.
Enlighten me on the problem, if you would, please.
As i read the abstract, it showed that 190nm radiation (UV) is required. That can't be too tricky to pump to, surely?
Found this extension but it still asks for account details...
http://www.nature.com/nature/journal/v414/n6864/full/414625a.html
Nature 414, 625-627 (6 December 2001) | doi:10.1038/414625a; Received 5 July 2001; Accepted 1 October 2001
The only problems are of the physical scaling: the kids'll soon sort that out, i don't doubt. ed.
Enlighten me on the problem, if you would, please.
As i read the abstract, it showed that 190nm radiation (UV) is required. That can't be too tricky to pump to, surely?
Found this extension but it still asks for account details...
http://www.nature.com/nature/journal/v414/n6864/full/414625a.html
Nature 414, 625-627 (6 December 2001) | doi:10.1038/414625a; Received 5 July 2001; Accepted 1 October 2001
The only problems are of the physical scaling: the kids'll soon sort that out, i don't doubt. ed.
The reason why it's not likely useful as a way of generating energy? Simply put: ever observed hydrogen coming from a glass of water in the sunlight?
http://en.wikipedia.org/wiki/Image:Solar_Spectrum.png ; 190nm isn't on it, but make an educated guess on the spectral irradiance?
Sure we can "pump 190nm radiation" into water, but that requires energy. So it's only an alternative to electrolysis of water, and as far as I know electrolysis itself is fairly efficient. I doubt photolysis by generated 190nm waves is more efficient.
In any case, the problem still lies with the input energy required to release hydrogen from water. There will always be a base amount of input energy required no matter what method you use (as can be determined by thermodynamics).
A process using exactly that amount would be 100% efficient. As I said, I think electrolysis is already quite efficient, so the problem mostly lies with the efficiency of the power stations generating the required energy. If you power a 80% efficient process from a 20% efficient power station, the overall efficiency is 16%. Make the process 90% efficient and it's 18%. Instead make the power station 30% efficient, and the overall efficiency is 24%.
Hydrogen economy has little use until we are able to obtain energy in a better way (by e.g. fusion).
P.S. I forgot to mention: the article you linked to uses indium-tantalum-oxide doped with nickel (to use other wavelenghts from sunlight in the photolysis). Those are some heavy metals and the efficiency has not yet exceeded the efficiency of photosynthesis (which basically is natural photolysis) - I explained above why even photosynthesis is not a useful way to meet our energy needs, as it would require large area's of the earth's surface to be used. The same goes for this story, until higher efficiency is found... and that's a big challenge with the solar spectrum.
http://en.wikipedia.org/wiki/Image:Solar_Spectrum.png ; 190nm isn't on it, but make an educated guess on the spectral irradiance?
Sure we can "pump 190nm radiation" into water, but that requires energy. So it's only an alternative to electrolysis of water, and as far as I know electrolysis itself is fairly efficient. I doubt photolysis by generated 190nm waves is more efficient.
In any case, the problem still lies with the input energy required to release hydrogen from water. There will always be a base amount of input energy required no matter what method you use (as can be determined by thermodynamics).
A process using exactly that amount would be 100% efficient. As I said, I think electrolysis is already quite efficient, so the problem mostly lies with the efficiency of the power stations generating the required energy. If you power a 80% efficient process from a 20% efficient power station, the overall efficiency is 16%. Make the process 90% efficient and it's 18%. Instead make the power station 30% efficient, and the overall efficiency is 24%.
Hydrogen economy has little use until we are able to obtain energy in a better way (by e.g. fusion).
P.S. I forgot to mention: the article you linked to uses indium-tantalum-oxide doped with nickel (to use other wavelenghts from sunlight in the photolysis). Those are some heavy metals and the efficiency has not yet exceeded the efficiency of photosynthesis (which basically is natural photolysis) - I explained above why even photosynthesis is not a useful way to meet our energy needs, as it would require large area's of the earth's surface to be used. The same goes for this story, until higher efficiency is found... and that's a big challenge with the solar spectrum.
http://www.theledlight.com/stylus_uv.html
through a frequency doubler and into l'eau should be fun at future 'gatherings'.
Cheers! ed.
through a frequency doubler and into l'eau should be fun at future 'gatherings'.
Cheers! ed.
I don't see the relation of that UV pen with this topic?
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| Powered by 3 “AAAA” alkaline batteries |
| Arnie wrote: | ||
I don't see the relation of that UV pen with this topic?
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190nm UV is the requirement.
Re-charge the primary PSU using these? http://www.magenn.com/ *
or other 'renewable' source e.g. tides.
* Posted elsewhere too.
So now you're admitting an external power source is required, and suggesting e.g. wind power. That's fine, but wind and solar power are currently not able to meet the worldwide energy need. So my long post still holds, with as main statement:
If we'd use wind power to generate hydrogen, the coal stations would have to provide more power to the households that were previously powered by the windmills. No net gain there.
Besides, what's the point in doing this with photolysis:
wind/whatever generated electricity --> battery --> UV light --> hydrogen
When you can do this with electrolysis:
wind/whatever generated electricity --> hydrogen
The overall efficiency of either chain is found by multiplying the efficiency factors of the chain. Guess which will be more efficient??
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| Hydrogen economy has little use until we are able to obtain energy in a better way (by e.g. fusion). |
Besides, what's the point in doing this with photolysis:
wind/whatever generated electricity --> battery --> UV light --> hydrogen
When you can do this with electrolysis:
wind/whatever generated electricity --> hydrogen
The overall efficiency of either chain is found by multiplying the efficiency factors of the chain. Guess which will be more efficient??
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