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Post by Nuclear on Nov 28, 2013 13:20:55 GMT 9.5
What do you think? What role should natural gas play on the way towards a low-carbon energy system? Should the use of natural gas to replace coal be promoted, perhaps through the imposition of a moderate carbon price? We saw that the US managed to achieve signficant cuts in overall greenhouse gas emissions from the power sector by switching from coal to gas. In addition to that, substituting coal with gas has additional health benefits because gas is clean-burning.
IMO natural gas has a role to play, especially if we assume less ambitious stabilization targets (550 - 650 ppm instead of 350 - 450 ppm). Gas can be scaled up faster than either nuclear or renewables and emits only half as much carbon dioxide as coal. If China were to start serious fracking operations on its vast shale reserves and satisfiy some of its rising energy demand by gas instead of coal, it would be very beneficial to the economy and the environment. Gas extraction would provide additional revenue to local communities and since gas is clean-burning, air pollution, which is a huge problem in China, could be reduced. In addition to that, emissions would rise more slowly.
I'm a climate change realist: The stabilization targets in the 350 - 450 ppm range are out of reach anyway. The nuclear/renewables/CCS build rates required to fully decarbonise most of the economy by 2050 -- even the scenarios portrayed here on BNC -- are perhaps technically possible, but they are economically and politically impossible. Nobody is going to build tens of thousands of new nuclear plants in the next 35 years. Our best hope is thus a more gradual reduction of emissions, towards a target of 550 or 650 ppm ... and in such a scenario, gas is a viable and economical bridge which could be used well into the 21st century. After 2040 - 2050 or so, however, the use of gas would have to decline significantly to avoid turning the bridge into a gangplank. However, those 30 to 40 years of additional time switching from coal to gas buys us can be used to make nuclear and renewables more economical than they currently are.
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Post by jagdish on Nov 28, 2013 20:06:52 GMT 9.5
Gas is a cleaner alternative to coal. It is also economical to coal in many locations. I guess it is alright where it is connected by pipeline. Big investments like liquefaction and regasification may be costly. It could give time for cheaper nuclear to be developed.
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Post by Roger Clifton on Nov 29, 2013 12:02:40 GMT 9.5
I see methane as a gangplank, with most of us willing to be misdirected to the abyss. Even the greenest of us seem to be willing to take up the blindfolds offered by the salesmen. The essay you have just read is inadvertantly full of sales talk, I guess because it has become the language of our peers. But do you believe it is virtuous, or is it misleading? I hope to read fellow readers' comments on each item. I start by saying, we should not call it "natural gas". Something so destructive to the greenhouse should not be called natural. When a questioner uses that term, let's reply using the honest term "methane", and deny confirmation to the other's self-deception. Leakage during its extraction and distribution releases more greenhouse gas than "half the CO2" when the methane burns, too. So we can't honestly call methane a "clean fuel" either. Methane can only fob us off with hopes of "achieving the target of", because there is no chance of closing on any target level for the greenhouse while we continue to emit anything at all. The climate that evolved us will continue to decay while we continue to tolerate pretences such as token "reductions of emissions" and empty promises of delayed "stabilising the climate", somehow and somewhen. So willing to believe our actions are innocent, we are guilty nonetheless. Building "tens of thousands of new nuclear plants" is exactly what we do need to do. Scoping how to do that is honourable work that you and I can be doing right here on the BNC blog.
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Post by Nuclear on Nov 29, 2013 13:09:32 GMT 9.5
I start by saying, we should not call it "natural gas". Something so destructive to the greenhouse should not be called natural. When a questioner uses that term, let's reply using the honest term "methane", and deny confirmation to the other's self-deception. Leakage during its extraction and distribution releases more greenhouse gas than "half the CO2" when the methane burns, too. So we can't honestly call methane a "clean fuel" either. It's called natural gas because it was produced by natural processes, as opposed to synthetic coal gas, which was used to light our cities and heat our homes before natural gas became prevalent. Methane leakage can be a problem, but if methane extraction is properly regulated it's not. There are several studies, including one funded by the Environmental Defense Fund, which confirm that in the US, methane leakage is indeed not a major problem. So burning methane instead of coal is a net benefit in terms of overall emission reductions. Methane can only fob us off with hopes of "achieving the target of", because there is no chance of closing on any target level for the greenhouse while we continue to emit anything at all. The climate that evolved us will continue to decay while we continue to tolerate pretences such as token "reductions of emissions" and empty promises of delayed "stabilising the climate", somehow and somewhen. So willing to believe our actions are innocent, we are guilty nonetheless. Building "tens of thousands of new nuclear plants" is exactly what we do need to do. Scoping how to do that is honourable work that you and I can be doing right here on the BNC blog. Yes, on the long run, emissions need to hit zero. So eventually, more than 10.000 new nuclear power plants or an equivalent power supply based entirely on renewables and storage will have to be built. But the question is, how long will it take to get there? Zero emissions by 2050 is simply not a realistic proposal, since it would require a vast, coordinated effort all across the globe. It would necessitate the opening of one new nuclear plant per day from 2013 till 2050. Reaching a stabilisation target of 450ppm is at odds with most of the world's political and economic priorities. Developing countries will continue to develop and they will do that using the cheapest forms of energy available, which is neither nuclear nor renewables, but fossil fuels. May I remind you of Roger Pielke Jr.'s Iron Law of Climate Change: “When policies focused on economic growth confront policies focused on emissions reduction, it is economic growth that will win out every time.” Surveys revealed that people are willing to pay for climate change mitigation, but they aren't willing to pay too much. They have other, more pressing priorities. In developing countries, this sentiment is even more pronounced. For countries like India or Bangladesh, which are especially vulnerable to climate change, economic development is nevertheless the top priority. From a climate change perspective, there is a certain logic to that: the richer a society, the easier it will be for it to cope with the effects of sudden climate change. So the world's priorities are clear. Emission reductions are secondary to economic growth. That means emissions will only be cut if those cuts are not at odds with potential growth. That's the -- admittedly somewhat depressing -- political and economic reality. What people who advocate serious action on climate change need to see is that the world will not decarbonise quickly enough unless low-carbon technologies gain an economic edge over fossil fuels. Currently, this is not the case. The US has shown, however, that the most begnin fossil fuel, natural gas, at least has the potential to affect deep cuts in the use of the most polluting fossil fuel, coal. Making gas cheaper and more attractive than coal should thus be a priority in other parts of the world too. China has vast, untapped shale reserves. If China expanded natural gas (in a responsible manner) AND nuclear instead of coal it would be a huge benefit to the climate change. Using more gas can buy us some time to fost innovation in low carbon techology. Yes, we will miss the 450ppm target, but that was never realistic to begin with. The best we can hope for is stabilising at 550ppm - 650 ppm and make the economy more resilient to dampen the effects of a 3°-4° rise in temperatures.
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Post by Roger Clifton on Nov 29, 2013 19:01:49 GMT 9.5
To say that methane is less evil than coal does not make methane good. Yet "Nuclear" repeatedly implies that methane is a good thing, so we can delay its replacement. No, we need urgently to make nuclear as cheap and plentiful as either of its competitors.
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Post by Nuclear on Nov 29, 2013 22:02:33 GMT 9.5
To say that methane is less evil than coal does not make methane good. Yet "Nuclear" repeatedly implies that methane is a good thing, so we can delay its replacement. No, we need urgently to make nuclear as cheap and plentiful as either of its competitors. Currently, the alternatives are either gas or coal. What choice do you make? A signficant expansion of zero-carbon energy generating technologies will take time and further innovation. Detached fundamentalism and black-and-white thinking is not what the energy debate needs. Here is an interesting paper discussing the value of a natural gas bridge in various stabilisation scenarios. www.cfr.org/natural-gas/climate-consequences-natural-gas-bridge-fuel/p29772
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Post by Grant on Nov 29, 2013 23:20:10 GMT 9.5
A couple of questions I have on natural gas as a bridge fuel substitute for coal. 1. Worldwide, how much natural gas is available for coal substitution? To put it another way, how much coal can be substituted for? A rough estimate is fine.
2. I've read that natural gas wells have a fairly short life span. So how long before natural gas peaks? A rough estimate is fine.
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Post by Roger Clifton on Dec 1, 2013 16:58:29 GMT 9.5
Grant asked, how much natural gas is available... ? There is an inexhaustible amount of "tight" methane resource around the world. Whenever organic matter gets buried, it decays anaerobically with the help of microorganisms, producing methane. If the deposit becomes shale the methane leaks out only slowly, its backpressure limiting further decay. Recently developed horizontal drilling technology taps the methane, which is thus known as "shale gas". Coal is among the richest organic deposits, and is correspondingly rich in methane. When extracted, the methane is known as "coal seam gas". Where methane is present in a sediment, it reduces any ferric ion to ferrous, thereby destroying any magnetic signature. Magnetic surveys routinely show sedimentary basins as largely transparent to the magnetic field, witness to the fact that there is methane galore in every sedimentary basin. What part of that resource is measured reserves, that is, commercially available, depends on the current price, the current technology and the current environmental laws set by a public that has been made dependent on "natural gas". The world is never going to run out of methane, though it will become environmentally more expensive the more "unconventionally" they drill. However, the world has already run out of somewhere to put its waste gases: the greenhouse is full.
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Post by jimbaerg on Dec 2, 2013 13:24:51 GMT 9.5
Either, depending on what is done with it. When I google "gas to liquids" I find a few companies like these two: www.gastechno.comwww.greyrock.com/claiming to have efficient ways that can be done on a small scale to turn natural gas into liquid fuels suitable for transportation. The really hard thing to do with anything other than fossil fuels is get mechanical power on a small scale without plugging into the electrical grid. Anything from chainsaws to jet planes. These gas to liquids technologies sound like they will produce liquid fuels with less CO2 emmissions than coal to liquids or bitumen to liquids. So I would count that use of natural gas as a 'bridge', while I would count using natural gas for electricity generation as a 'gang plank'.
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Post by edireland on Dec 2, 2013 17:04:41 GMT 9.5
We do indeed have container sized F-T or comparable process units now, although they are not as efficient as the monster plants like the Pearl GTL complex.
It is likely that the product of such plants would be methanol or heavy wax which can then be process elsewhere as on site cracking or dehydration equipment is rather expensive.
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Post by Grant on Dec 2, 2013 17:45:59 GMT 9.5
Nuclear
I would think there was a choking point where that priority would change. China appears to be arriving there in many areas of the country. As an added thought, I think we might be moving toward an economics of sustainable steady state rather than endless growth; more along the lines of Mother Nature.
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Post by edireland on Dec 2, 2013 19:45:56 GMT 9.5
'Steady State Economics' is a rather ominous term once you realise the side effects of having an economy that never grows any larger.
It turns social mobility and improvements in living standards for the poor into essentially a zero sum game - turning the rich and middle class against measures which do improve the lot of the poor.
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Post by Grant on Dec 2, 2013 22:24:05 GMT 9.5
'Steady State Economics' is a rather ominous term once you realise the side effects of having an economy that never grows any larger. It turns social mobility and improvements in living standards for the poor into essentially a zero sum game - turning the rich and middle class against measures which do improve the lot of the poor. How about moving toward 'Share the Wealth', less waste and energy use and a decreasing population. That may sound unrealistic but so is the present course. To a large degree this thread seems to be about dying at half speed rather than full speed. Maybe a shift in the paradigm is worth considering.
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Post by edireland on Dec 3, 2013 0:37:41 GMT 9.5
'Share the wealth' still means a zero sum game, which means the rich and middle classes will not support it out of fear of what will happen to them.
The human race will survive 'Global Warming', so this is not about preventing the extinction of the species or anything like that. It may not be a nice transistion to a new world, littered with millions of dead, but it is not going to bring down civilisation.
If nuclear transistion can be carried out there is no real reason to place limits on energy consumption or population growth, because the former essentially ceases to be damaging. Population Growth can easily be accomodated in an energy-cheap world as you can withdraw animal feed crops (and fishmeal) that eat up titanic amounts of arable land in favour of things like pruteen.
Pruteen permits food production to be decoupled from land use, and then there is the constantly advancing grasp of material science that is now starting to deliver Collosal Carbon Tubes and Carbon Nanotubes of ridiculous strength.
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Post by Grant on Dec 3, 2013 2:27:14 GMT 9.5
Under sufficiently extreme conditions the minority will bow to the majority. Historically the expression "Let them eat cake" comes to mind before le deluge. I'm not sure why we would be exempt. We are the last members standing of a very fragile group known as hominids. The last time we had a severe drop in population, ie the plague, it took basically one type of bug to bring that about and under generally agreeable climatic conditions. The situation is getting a lot worse than then and the natural buffers are weaker. Our environmental support systems are broadly moving south which takes us to all sorts of end game scenarios. A nuclear transition being successfully carried out without considering energy consumption or population is beyond my pay grade. I'll leave that extraordinary vision to you. I definitely get that we have to move toward vegetarianism with some sustainable animal and fishing practices allowed. In general I get my expertise on agriculture from Lester Brown of Earth Policy Institute. He sees agricultural output generally going down 5% for every 1 deg C increase. He also sees our topsoil being steadily degraded and our water sources, from rivers and lakes, to mountain snow-ice storage, to aquifers drying up and/or being polluted. Add loss of forest to the equation driven by guess what, increased population, and things aren't looking so good.
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Post by edireland on Dec 3, 2013 11:46:42 GMT 9.5
Technologies such as Single Celled Protein produced on methanol potentially allow offpeak nuclear energy (available at a couple of cents per kWh in a large scale programme) to be converted into animal feed.
That tends to make animal and fish raising less environmentally damaging than conventional crops. Additionally a large part of the worlds arable land (primarily in Africa) has not been developed to its maximum potential with western style 'scientific agriculture' that prevents significant soil degradation while producing enormous yields.
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Post by Grant on Dec 3, 2013 16:35:57 GMT 9.5
No doubt SCPs(Single Cell Proteins), yeast, algae and bacteria, feeding off of various bio-wastes and fossil fuel derived inputs will keep us in protein for a good while, either directly or indirectly through animal feed. Nice to get educated on the subject. Here are a couple of links I found useful. Single Cell Protein: Production and Process Single-Cell ProteinsNext, water scarcity and then we can move on to the next challenge. No doubt recycling and desalination is going to part of some solution. I remember Buckminster Fuller saying we needed to push hard for long term space travel because that was the only way we would be motivated to come up with a total recycling solution which then could be re-employed back on earth. Anyway a look into the problem of water deficits we can look forward to as now being experienced in the Arab world.
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Post by edireland on Dec 4, 2013 0:25:20 GMT 9.5
Well ironically, in the UK at least, the price of desalination has fallen below the average cost of agricultural water. But obviously the UKs irrigation inputs are far lower than elsewhere.
Singapore claims to be able to deliver chip-fab quality water (so the purest of the pure water) for about 15 US cents per cubic metre using NEWater recycling systems, but I am not sure how much of the input water is rejected as the 'brine' in that process so I can't predict how much water you can actually get out of that.
55 cents a cubic metre and gradually falling is the price I hear coming out of Israel these days, but I am not sure how that translates to the west where everything seems to cost ridiculous amoutns more for no apparent reason.
If nuclear reactors are better at anything than electricity production it is producing ridiculous quantities of cheap steam, so it seems possible that Multiple Effect Distillation will be able to keep up or even better Reverse Osmosis costs once the reduced heat costs are factored in.
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Post by trag on Dec 4, 2013 2:17:21 GMT 9.5
55 cents a cubic metre and gradually falling is the price I hear coming out of Israel these days, but I am not sure how that translates to the west where everything seems to cost ridiculous amoutns more for no apparent reason. That's about $2.20 per 1000 gallons for anyone who wants to know how it compares to their utility water bill. Was that the Israeli water recycling cost or desalination cost?
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Post by edireland on Dec 4, 2013 4:40:51 GMT 9.5
(55 cents per cubic metre is rather less than I pay in Britain for my water, even excluding sewerage charges - our charges are per cubic metre)
That was desalination at the newly opened PFI funded plant near Aqaba. They claim that they will have 35 cents per cubic metre in a few years more with the increasing economies of scale and improvements in filter technology.
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Post by Roger Clifton on Dec 4, 2013 13:17:38 GMT 9.5
EdIreland said: "possible... Multiple Effect Distillation will be able to keep up or even better Reverse Osmosis costs once the reduced heat costs are factored in" Because multiple stage flash distillation uses exhaust heat rather than a significant slice of electric output, desalination can proceed or even increase at times of peak load. Reverse osmosis has to pay for its electricity, so presumably would idle its plant at peak load rather than pay peak rates. If peak load is in high summer, it might also be the time of highest demand on freshwater, so MED would be favoured over RO. If nuclear energy were touted as a supply of "power and water", it might more easily be budgeted from the public purse. Nuclear need not derided as a particularly high consumer of potable water if it is recognised as a producer of water in a combined operation.
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Post by Ed Leaver on Dec 5, 2013 5:38:44 GMT 9.5
Why -- apart from ignorance -- should nuclear be derided as a particularly high consumer of potable water? Not that some older plants are not such high consumers -- but they were built at sites where water was thought at the time to be plentiful. Otherwise, doesn't the plant designer just resign himself to going the coal route and including a cooling tower? I share Grant's concerns r.e. population growth. Fortunately, contrary group behaviors notwithstanding, homo sapiens sapiens on the individual level actually is fairly sapient, and given a modicum of education and access to health care the species does pretty well at self-limiting its population. Of course, education and health care are predicated upon healthful food and water, in turn on reasonably abundant low-cost energy.
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Post by Roger Clifton on Dec 5, 2013 12:47:14 GMT 9.5
@ Ed Leaver: Yes, nukes were built where water seemed plentiful -- and consumed plenty. Inland from the sea or any great river, a power station would need to be either air cooled or continuously desalinating. When water-cooling is used, nukes appear greediest: If the efficiency of the nuclear power station is 25%, then (1-.25)/.25 = 3 times its electric power would have to be dumped into the air as latent heat in evaporated water. A coal-fired power station at 33% efficiency would have to dump (1-.33)/.33 = 2 times its electric power as evaporated water plus hot stack gas at some unknown fraction(*). So it would appear to consume about half as much water as the nuke. Gas: A CCGT at 60% efficiency dumps (1-.6)/.6 = 2/3 of its electric power into hot exhaust gas plus a relatively small water consumption. An OCGT (peaker) at 25% efficiency must dump three times its electric power output as waste heat, but it is wholly in the exhaust gas. Air cooling costs about 6% of the electric power output to drive its fans. The mPower SMR, the current front runner to become the first mass produced nuke, uses air cooling. (*)PS: WNN page on cooling says about 15% of the waste heat goes up the stack on a modern coal-fired power plant.
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Post by edireland on Dec 6, 2013 2:39:15 GMT 9.5
Why not just use HVDC to supply inland areas?
Its much cheaper than air cooling
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Post by Roger Clifton on Dec 6, 2013 8:19:22 GMT 9.5
@ EdIreland ... You paint a vision of powerful generators along the coast, cooling cheaply with sea water, and supplying power to the inland using efficient HVDC backbone to the grid. Running costs of air cooling include 6% of the power output. How many kilometres of HVDC does it take to accumulate 6% resistive losses? One of the less tangible capital costs of seawater cooling is the high visibility of the power station structure inserted into a crowded coastline. These once used to be proud, perhaps arrogant, symbols of progress, but now for many they are confronting symbols to be torn down.
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Post by Ed Leaver on Dec 6, 2013 10:39:38 GMT 9.5
Westinghouse claims 33% thermal efficiency for AP1000. This is typical for existing coal plants as well, although modern designs can do 40% and Denmark' Avedore plant reaches 49%. Surely a cooling tower arrangement requires some water: but only about 5% that required by direct river or ocean cooling, assuming no more than 25C rise in river water temperature. That 540 cal/grdegC latent heat of evaporation adds up in a hurry. I mean sure, if the water just isn't there or is really costly (same thing) then go with air cooling. In HTGR's it might be cheaper anyway as these supposedly will reach 50% efficiency. But for "current" large-scale GW+ Gen III+ LWR's, I suspect the cooling water requirements will not be excessively greater than the coal plants they are to replace.
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Post by edireland on Dec 6, 2013 22:08:47 GMT 9.5
@ EdIreland ... You paint a vision of powerful generators along the coast, cooling cheaply with sea water, and supplying power to the inland using efficient HVDC backbone to the grid. Running costs of air cooling include 6% of the power output. How many kilometres of HVDC does it take to accumulate 6% resistive losses? The answer turns out to be... quite a long distance. Apparently about 1000km according to this diagram from ABB. You loose 1.2% of the power transmitted in the converter stations but then you can get far lower losses due to higher average voltage and the lack of skin-effect related issues. Then you have to include the other savings from using seawater cooling such as the ability to pack far more generating capacity onto the same site. I wouldn't like to see the cooling equipment necessary to air cool several gigawatts of power generating capacity from a large multi-reactor plant. One of the less tangible capital costs of seawater cooling is the high visibility of the power station structure inserted into a crowded coastline. These once used to be proud, perhaps arrogant, symbols of progress, but now for many they are confronting symbols to be torn down. The amount of coastline required for a large plant is quite small though. For instance Gravelines Nuclear Power Plant has six 900MWe class PWRs and only has a seawater frontage of roughly 1300m, which could easily be cut to roughly 650m if some ancillary services which are besides the reactor were instead positioned behind them. (It appears to be office buildings, car parks and similar facilities). Using modern, larger, reactors potentially gives an even larger power density in terms of coastline consumed, up to 9GWe per 650m length, or nearly 14GW/km. EDIT: Extrapolating from that ABB diagram, it would appear that even attemting to transmit 1200MWe power from the Ocean to the EPIA1 'Eurasian Pole of Inaccesibility' (the most distant point on Eurasia and indeed the Earth from the ocean, a distance of approximately 2500km) would only produce a loss of 200MWe, or roughly 14%, which while high is not catastrophically so. It appears that air cooling of reactors is of questionable usefulness, considering that higher HVDC voltages than the 400kV used in the example are now available.
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Post by Ed Leaver on Dec 7, 2013 6:03:16 GMT 9.5
If you're speaking of Australia and no geopolitical barriers to HVDC then sure. In the U.S. the Pacific DC Intertie -- in service since 1970 -- shunts 3.1GW electric 1,362 km from the Columbia River gorge to Los Angeles at 500 DC on each pole (1 kV differential). But I suspect it will depend on the economics of each case. The important thing is our embarrassment of viable solutions.
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Post by Roger Clifton on Dec 7, 2013 17:21:01 GMT 9.5
EdIreland said: >"I wouldn't like to see the cooling equipment necessary to air cool several gigawatts of power generating capacity from a large multi-reactor plant." Here is an image of passive draft/draught equipment planned to cool 5 GW(e) of AP1000s. A good summary of cooling systems is available on WNN site. You guys could have pulled me up on my use of " or desalinating". If several gigawatts of waste heat were cycled through several distillations of water, the copious sweet water coming out of the plant would still be carrying several gigawatts of heat. Because the pipework would be below 100° it would have to cool passively. I imagine a pipe farm of ~1 km² per gigawatt of heat to be shed. Beloved of glider pilots and wildlife in winter! But then, my own interest is in much smaller NPP's. Yes, they require more capital per watt, both in dollars and in political effort to persuade the locals, but in places like here in Oz, a few small, unobtrusively inland fan-cooled NPPs may be all that is achievable - to begin with.
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Post by edireland on Dec 8, 2013 2:02:04 GMT 9.5
That equipment is going to be titanically expensive.
And I believe with MED plants the majority of the waste heat will end up in the reject brine which ends up dumping straight back into the sea again.
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