jkljkl Posted October 14, 2007 Report Share Posted October 14, 2007 Energy storage is a fairly interesting topic. [snip]A couple years back, I spent a month or so running numbers trying to see whether or not it would be practical to install flywheels in houses as a storage system. There are already scenarios for the day that we have many vehicles powered by electric energy. The electrical companies would not only recharge your batteries but also pull energy out of them to a certain degree in peak times. Another topic regarding atomic energy that I find interesting, is the role of de facto electrical monoplies intersted in huge centralized facilities opposed to decentralized combined heat and power plants. ciao stefan i have no idea what this post means. 1) de facto monopolies? what is a de facto monoply compared to a facto or other monopopy....in other words...you just seem to run random words together with no real meaning2) how do they pull electricity....no in other words how do they store electicity and then pull it?3) what is centralized electricity compared to noncenralized electricity....in other words how are you storing it? Sorry, if my post wasn't clear. I was adding my two cents to the topic that the amount of electricity needed by a nation is not costant at every hour of the day. About 2)To cover peak times demand, the electrical companies store electricity that they have produced in "no-peak" times. A way to to this is for instance to build a big water bassin on the top of a moutnain. If you have a surplus of electrical energy (you can't switch a big electriity plant on and off as you do with your radio) you pump water up to this bassin. Then if you are suddenly in need of electricity (peak-time). You invert the process. Basically to a hydroelectric power plant. So the energy goes from electric to kinetic and eventually back. Another way to store energy is to use accumulator batteries. There you transform the electrical energy into a reversible chemical reaction and eventually back. The downside of this second method is that the costs for an accumultor battery is very high and so you would not use this method if your only aim is to store energy without having the need to carry it around. Now back to the scenario in my original post. Here the electrical companies get a huge amount of accumulator batteries for free, the batteries being located in our cars and the cars being connected to the national electrical grid while recharging.In "no-peak -times" the accumulators in your car are charged to a maximum and you pay this electrical energy. In "peak-times" they will take electrical energy out of your car till a certain degree and of course you get a bonus for that. About 1)Several energy companies here in europe had a monopoly in their countries in the past. Now we are trying to make a shift to a free market but in this shift. amongst other problems, the electrical grid stayed in the hand of the former monopolist. So on paper a free market but de facto if you try to set up an alternative you will have a hard time.One alternative I mentioned could be "combined heat and power plants" (CHP) that have a ver high degree of efficiency. I hope this helped,best regardsstefan Quote Link to comment Share on other sites More sharing options...
mike777 Posted October 14, 2007 Report Share Posted October 14, 2007 Energy storage is a fairly interesting topic. [snip]A couple years back, I spent a month or so running numbers trying to see whether or not it would be practical to install flywheels in houses as a storage system. There are already scenarios for the day that we have many vehicles powered by electric energy. The electrical companies would not only recharge your batteries but also pull energy out of them to a certain degree in peak times. Another topic regarding atomic energy that I find interesting, is the role of de facto electrical monoplies intersted in huge centralized facilities opposed to decentralized combined heat and power plants. ciao stefan i have no idea what this post means. 1) de facto monopolies? what is a de facto monoply compared to a facto or other monopopy....in other words...you just seem to run random words together with no real meaning2) how do they pull electricity....no in other words how do they store electicity and then pull it?3) what is centralized electricity compared to noncenralized electricity....in other words how are you storing it? Sorry, if my post wasn't clear. I was adding my two cents to the topic that the amount of electricity needed by a nation is not costant at every hour of the day. About 2)To cover peak times demand, the electrical companies store electricity that they have produced in "no-peak" times. A way to to this is for instance to build a big water bassin on the top of a moutnain. If you have a surplus of electrical energy (you can't switch a big electriity plant on and off as you do with your radio) you pump water up to this bassin. Then if you are suddenly in need of electricity (peak-time). You invert the process. Basically to a hydroelectric power plant. So the energy goes from electric to kinetic and eventually back. Another way to store energy is to use accumulator batteries. There you transform the electrical energy into a reversible chemical reaction and eventually back. The downside of this second method is that the costs for an accumultor battery is very high and so you would not use this method if your only aim is to store energy without having the need to carry it around. Now back to the scenario in my original post. Here the electrical companies get a huge amount of accumulator batteries for free, the batteries being located in our cars and the cars being connected to the national electrical grid while recharging.In "no-peak -times" the accumulators in your car are charged to a maximum and you pay this electrical energy. In "peak-times" they will take electrical energy out of your car till a certain degree and of course you get a bonus for that. About 1)Several energy companies here in europe had a monopoly in their countries in the past. Now we are trying to make a shift to a free market but in this shift. amongst other problems, the electrical grid stayed in the hand of the former monopolist. So on paper a free market but de facto if you try to set up an alternative you will have a hard time.One alternative I mentioned could be "combined heat and power plants" (CHP) that have a ver high degree of efficiency. I hope this helped,best regardsstefan I may not have made my self clear. I do not know how to store electricity.... Too repeat I do not in any, any way mean to minimize your comments....if you know how to store electricity....pls tell any physics professor...this is a real problem...... If you know how and have done it....please post........ or send to some physics prof....thank you. Quote Link to comment Share on other sites More sharing options...
helene_t Posted October 14, 2007 Report Share Posted October 14, 2007 MIke, if by storing electricity you think of something like a condensator, then it´s not so relevant for the purpose of energy supply. The relevant thing is to convert electric energy into some kind of energy storable energy. Several methods (hydrogen, water reservoirs, flywheels) have been mentioned. Quote Link to comment Share on other sites More sharing options...
jkljkl Posted October 14, 2007 Report Share Posted October 14, 2007 I may not have made my self clear. I do not know how to store electricity.... If you know how and have done it....please post........ or send to some physics prof....thank you. I think you made yourself clear, you are up to word games. If a sentence as "So the energy goes from electric to kinetic and eventually back." doesen't suffice you I give up. ciao stefan Quote Link to comment Share on other sites More sharing options...
mike777 Posted October 14, 2007 Report Share Posted October 14, 2007 MIke, if by storing electricity you think of something like a condensator, then it´s not so relevant for the purpose of energy supply. The relevant thing is to convert electric energy into some kind of energy storable energy. Several methods (hydrogen, water reservoirs, flywheels) have been mentioned. No...this is a huge unsolved problem....... If you have the answer ..great...just tell your prof...... I repeat.... figuring out how to store electicity is a huge...?,...THE energy problem....not nuke power plants...:P I am not trying to use some tricky word games...just plain english..........from what I read..this is The number one...energy..... issue........not number 50........ As usual if we cannot agree on exactly what the problem is......solving is going to be tough....:) Quote Link to comment Share on other sites More sharing options...
hrothgar Posted October 14, 2007 Report Share Posted October 14, 2007 No...this is a huge unsolved problem....... If you have the answer ..great...just tell your prof...... I repeat.... figuring out how to store electicity is a huge...?,...THE energy problem....not nuke power plants...:P I am not trying to use some tricky word games...just plain english..........from what I read..this is The number one...energy..... issue........not number 50........ As usual if we cannot agree on exactly what the problem is......solving is going to be tough....:) As is oft the case, you aren't doing a very good expressing yourself: I tried to point out earlier that you need to narrow the focus the this discussion and define some basic expressions. 1. There are ways to store electricity: A capacitor is the most obvious example. 2. There are a plethora of ways in which one can transform electricity into some form of potential energy and then transform this potential energy back into electricity. One might argue that it would be great if these types of systems operated more efficiently, they were cheaper to build, or they were able to handle more discharge cycles before degrading, what have you. I do not know how to store electricity.... Then I recommend that you spend some time familiarizing yourself with the following concepts 1. Battery2. Capacitor3. Pump Storage4. Flywheel Quote Link to comment Share on other sites More sharing options...
helene_t Posted October 14, 2007 Report Share Posted October 14, 2007 As usual if we cannot agree on exactly what the problem is......solving is going to be tough....:P The original topic of this thread was whether the Indian government should opt for nuclear energy. Since this happens to be a government decision in India and since India happens to be a democratic country, that issue is of interest to Indian citizens. Do you think that research in energy storage technology deserves more government money than does research in nuclear energy? Fair enough, I might even agree with you, but this thread is about nuclear energy, particularly the use of nuclear energy in India. Quote Link to comment Share on other sites More sharing options...
Wackojack Posted October 14, 2007 Report Share Posted October 14, 2007 Hypothetically, just suppose that I am an energy consultant with an international reputation for integrity and professionalism. I am approached by the goverment of a hypothetical nation who's recent encomomic dynamism is putting it into the big league. They need to build many more power stations to keep up with their energy needs and can see that if they build more of their present generation of fossil fuel stations, they won't meet their targets for carbon emissions that they signed up to a the most recent climate change conference. This I stress is purely hypothetical. They have called on me to make an independent assessment of what their strategy should be for producing electrical power. Lets assume I have the resources to call upon the help of energy experts and economists to assess the present state of knowlege and highlight where more questions need to be answered. Also I have a working relationship with university professors in this field who can call on PhD students to help with risk and econometric analysis etc, to help answer some of these questions. Suppose at the end of this mammoth task, all the evidence points to nuclear power being safer, cheaper and cleaner than other means of generating electricity. Then would I recommend just building nuclear stations? Of course not. Why not? 1. Electricity cannot be stored. Literally on a second by second basis the supply of electrical energy has to match the demand taken. If you switch on an electric kettle after watching a TV program a little bit more power has to come out of the generators connected to the power system. Indeed, their is a team of engineers who forecast the what the "TV pick-up" will be after popular TV programmes. If they get it too wrong, something bad will happen. If there is an excess of electricity generated, all the generators in the country will speed up and if this exceeds certain safetey limits, the overspeeding generators will automatically trip off the system. Thus it will change from excess supply to excess demand. The remaining generators will slow down very quickly bringing in automic tripping of load on low frequency. (We are talking about fractions of a second) If you are unlucky you get blacked out. If you are very unlucky everybody gets blacked out. OK the forcasters have to get it very wrong for this to happen but I am illustrating a point that storage has to be available in a fraction of a second. Leave capacitors and batteries aside for the moment. Now how does this affect nuclear power? First of all nuclear reacors take a long time to start up and get to full load. So once you get them there, you don't want to shut them down again. Incidentally if a nuclear generator is tripped off the system on full load, the safety systems of the reactor will have to operate. Also true of any other generator except that the worst that could happen if the saftey systems didn't operate would be that the generator flies out through the roof and a possible boiler fire. I digress. During the day every day the demand for electricity varies, the peak demand being of the order of twice the minimum demand. This means that you would have to bring off about 50% of your generators every day. This is not possible if you have more than 50% of nuclear generation. Unless you have energy storage....... Pumped storage generation is a useful partner to nuclear power. Why? Because you can keep nuclear generators running at off-peak times. The excess is used to pump water up to a reservoir which is available to generate electricity a peak times. Of course if you are France you can sell your excess nuclear to the UK because most of the time French electricy (nuclear) is cheaper than UK electricity (predominately fossil fuel). Another good thing about pumped storage electricity is these stations can get to full load in a few seconds which help stabilise the system frequency. Flywheels have been touted as a means of storing electricity. Not really viable on any time basis beyond a few seconds. A fair sized flywheel sited in say a local electricity substation would have the equivalent energy storage of a single 500MW generator running for a few seconds. So could at best be used to stabilise frquency on a fraction of a second time basis. Besides generators connected to the power system are in effect flywheels themselves. Also remember that flywheels consume electricity no matter how efficient. Capacitors for more or less the same reasons are not viable for electricity storage. One use for capacitors on the electricity system is to keep the voltage stable. Another digression is about voltage stability of the power system. Fawley power station built just by an oil refinery during the 60's was supposed to be a show piece and was the most thermally efficient power station in the UK. Then because of the differential cost of fuel going against oil they wanted to close it down. But they still needed it, not to generate real power but to generate imaginary power. This imaginary power represented by a number multiplied by the square root of minus one is necessary to keep the voltage down at off peak demand and helps to keep the voltage up at peak demand when negative imaginary power has to be generated. Capacitors generate imaginary power too. 2. Would nuclear power be publicly acceptable? Nuclear power stations use a thermodynamic cycle to convert heat energy fron a reactor into electrical energy. As with fossil fuel stations they raise steam in a boiler which is passed through a turbine on the same shaft as an electricity generator. The heat given up by the steam represents the useful energy converted into torque on the turbine shaft which in turn converts to an electrical output of the generator. Unfortunately the best themodynamic efficiency you can get out of this cycle is about 40%. (Actually better than the Carnot cycle in motor vehicles) What do you do with the 60% waste heat? I am sure everyone would have noticed the giant cooling towers surrounding steam raising power stations. What you see coming out of them is just water vapour (so in theory non polluting). However they do tend to make clouds. Of course again this excess could instead be piped around the city to keep us warm on cold days. Why is this so rarely done? Perhaps a clue later. Nuclear stations in the UK are on the coast or broad estuaries. This means that the excess heat can directly be discharged into the sea without the need for cooling towers. A river heat-up would be unacceptable. OK suppose that there was a major new building new project in your client nation's capital city. Say for the olympic games. The olympic site was by the river that ran through the city and you could get a district heating company to make an attractive quote to supply the olympic complex including major residential dwellings. You propose to recommend a nuclear station to be built there using its waste heat. Would this be publicly acceptable? I think not. I personally would still have nagging doubts about safety. Not so much a major meltdown but low level safety incidents. Lets take an example. Recently there was an outbreak of foot-and-mouth disease in cattle not far from where I live in England. It was ascertained to have come from a goverment research laboratory in Pirbright very close to the outbreak. At this laboratory, they were working on developing a vaccine against this disease. Investigation revealed that a waste pipe used to carry contaminated liquid to a containment area was cracked. During heavy rain and flooding the infected leak got into the ground water. Like wise, low level radio-active leaks have occurred at nuclear sites and no doubt they will happen again. It may be a very different matter accidentally discharging a small amound of radio-active waste into the sea which rapidly dilutes to below danger level than into a city river. London gets its drinking water from the Thames. Risk analysers often quote odds on the basis of saying that for something bad to happen it has to be the combination of a number of unlikely independent events and therefore the odds are vanishingly small. Common mode causes are not found. I think enough said except that probably the worst danger of people dying comes from a major black-out. We utterly depend electricity in every aspect of our life. Get a national black-out on a bad day and many will die. Quote Link to comment Share on other sites More sharing options...
zasanya Posted October 14, 2007 Author Report Share Posted October 14, 2007 Some figures (source:http://www.cslforum.org/) USA generates 3892 Billion kilowatt hours of electricity.This includes 764 BKh by way of Nuclear means and 2759 BKh by way of conventional thermal means.India generates 587 BKh .This includes 18 BKh by way of nuclear means and 486 BKh by way of conventional thermal means.France generates 537 BKH.This includes 419 BKh by way of Nuclear means and 55 BKh by way of conventional thermal means. Does anyone know the reason why France opted for the nuclear method? Quote Link to comment Share on other sites More sharing options...
Winstonm Posted October 14, 2007 Report Share Posted October 14, 2007 Does anyone know the reason why France opted for the nuclear method? Quite obviously this is a ruse to mask their determination to create nuclear weapons. Prepare for Operation France Freedom! What's that? No oil in France? Never mind. perhaps more attention could be given on how to store electricity I say we find a mate for that pink rabbit with the drum and then let nature take its course. Quote Link to comment Share on other sites More sharing options...
Gerben42 Posted October 15, 2007 Report Share Posted October 15, 2007 Possibly interesting link: UK EPR generic design assessment This site is part of a public licencing procedure for the EPR in the United Kingdom. Quote Link to comment Share on other sites More sharing options...
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