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Post by davidm on May 21, 2012 16:46:01 GMT 9.5
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Post by anonposter on May 21, 2012 17:31:05 GMT 9.5
Then why can't they show a country which gets close to 100% of their electricity from non-hydro renewable sources? It's almost as if they've just calculated how much energy is available on Earth without bothering with how it'll be used.
Though the fact that they are assuming that energy efficiency will halve energy demand also indicates that it's unrealistic, commercial and industrial energy use (which dwarf residential use) don't have anywhere near as much scope for gain.
I personally won't give credit for trying, I'll give credit for results and so far renewable energy has not delivered on its promises (it's getting to be like fusion, always 30 years away, only fusion actually might one day work).
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Post by sod on May 22, 2012 5:54:23 GMT 9.5
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Post by max on May 22, 2012 13:15:58 GMT 9.5
Even if the LOCE of wind power in some regions is equal or below that of nuclear, wind requires grid level storage, which leads to substantial cost increases. Nuclear thus retains its competitive edge. In addition to that it is much easier on the environment, since its ecological footprint is much smaller thanks to the tremendous power density.
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Post by anonposter on May 22, 2012 16:28:14 GMT 9.5
i dislike the "100%" discussion, as i think there are many unknowns, looking 40 years into the future. Whether we will really achieve 100% renewables depends on technical revolutions and political developments, and both are extremely hard to predict. The technical development you'd need for Earth based renewable energy to be viable is energy storage on larger scale than pumped hydro and that doesn't seem likely enough to come about to depend on. Lower space launch costs and space mining could allow space solar to be viable (and probably will, but not right now when we need to be solving global warming). The political problem renewables face is that eventually the public is going to realise that they don't damn well work a which point the subsidies (including feed in tariffs) will disappear and the whole bubble will collapse, just as Tulips did. they are placing the right focus and they are at least trying to do a realistic assessment. Sorry, they're just making up numbers as far as their demand side is concerned (there is no way we'll have lower energy usage on a global scale with ≈10 billion people at a first world standard of living). conservation can and will be done. Then Jevons paradox may appear (and if conservation were as easy as the conservatives claim why hasn't it been done? I mean people like you have bleating about it for decades). especially in "nonresidential construction". Even before 2050, all new buildings will use basically no energy after building. Right, so the buildings will magically be cool in summer, warm in winter and have zero-energy lights (which actually are possible, with enough Radium) for those who need to work at night? It will be much harder to change old buildings, and this will require massive political effort. (as noticed in the link in the original post..) What if the owners like the buildings as they are? renewables will form the vast majority of energy production in 2050, Only if space solar takes off will renewables even form a significant proportion of energy production then (though fusion might also be a contender then). Right now the only significant renewables are hydro and biomass and we really don't have much scope to increase those so as global energy consumption increases they will become less significant (and there are good anti-pollution reasons to get off biofuels). as even big companies like RWE are moving into this sector now for pure economic reasons. Government subsidies are economic reasons. But if there were no subsidies no one with any business sense would touch renewable energy on a large scale (it can be useful for off the grid situations though). summer peak time electricity will be mostly solar power in countries as north as Germany. Actually it's really be methane but with some shiny solar panels the power company would rather you look at instead (you'll need to back up the solar panels in case of cloud). but whether 100% can be achieved depends on what will fill the gaps. If you actually tried for 100% renewable and don't have enough rivers to be 100% hyrdo the gap would be filled with rolling blackouts ([sarcasm]which are always politically population[/sarcasm]). and there we depend on technological (mostly storage) and political solutions (how to keep the oil/coal countries from burning cheap fossil). Making nuclear cheaper than coal and oil would seem to be a better way to keep countries with cheap fossil fuels from burning them. Even if the LOCE of wind power in some regions is equal or below that of nuclear, wind requires grid level storage, which leads to substantial cost increases. Nuclear thus retains its competitive edge. In addition to that it is much easier on the environment, since its ecological footprint is much smaller thanks to the tremendous power density. Quite true, the cost of intermittent renewable energy such as wind and ground based solar should include the cost (and emissions) of back up power or energy storage in any comparison made with reliable energy sources such as nuclear and fossil fuels.
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Post by sod on May 23, 2012 4:29:59 GMT 9.5
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Post by proteos on May 23, 2012 5:52:55 GMT 9.5
Then why can't they show a country which gets close to 100% of their electricity from non-hydro renewable sources? It's almost as if they've just calculated how much energy is available on Earth without bothering with how it'll be used. I think it is not fair to use such an argument. In essence, you are saying that it has never been done and that proves that will be impossible forever. The fact is that is no proof. Before nuclear power appeared, no one was using it, so it should have meant it was impossible to provide most of electricity out of it. Yet it is in fact possible, as the case of France (and Lithuania ) demonstrates. I personally won't give credit for trying, I'll give credit for results and so far renewable energy has not delivered on its promises (it's getting to be like fusion, always 30 years away, only fusion actually might one day work). This is a more compelling argument. It is true that renewable sources of electricity like wind and solar (as opposed to hydro) have failed to make a big difference in the carbon emissions of the countries that have pushed hard for them in the last 10 years. The nuclear push of Sweden has had much better results as Sweden nearly halved its per capita emissions from burning fossil fuels between 1971 and 1990 (source: IEA CO2 highlights table p97). The results from Danemark are much less convincing, and yet it's been 15 years now that the wind push has begun. But then again, it does not prove it won't work. It may mean it's not the easiest path or that some elements are missing. Thus, I think it is important to look into the "100% renewables" scenarios to see what's actually missing and if it's possible that things will improve in the medium term (that is: before it's too late). Germany has provided quite a few recently (freely available): see here for a list. My opinion on 2 of the scenarios: - the UBA scenario (made by IWES, so it relies on wind) there's an english summary but the rest is in german. The graphs & tables say most of what there is to understand. It's a combination of wind (maxed out for them) and solar PV (not maxed out but in competition with solar thermal), plus electrolysis for storage. The main problems I see: the capacity factor for wind esp. onshore is too high compared to what exists today (35% vs 18%). Of course with that you can run some storage. The efficiency of the storage looks pretty high to me, as pumping H2 cost relatively more than methane because of the lower energy content per unit volume. Solar dominance in the summer forces a feeding frenzy behavior there. Stationnary power is high, with low capacity factors, I wonder how such facilities can make economic sense. And finally, the scenario looks like it aims for a self sufficient Germany, yet ends up importing lots of electricity.
- the SRU scenario : again a wind based scenario. It also looks at Germany integrated with Norway (for pumping storage). There, offshore wind can reach a capacity factor of nearly 50% (!), be one of the cheapest energy on earth at ¤41/MWh and it needs between 45 and 70GW of transmission capacity between Germany and Norway (see for example tables p107). Wow!
To summarize, it seems to me that 100% renewables scenarios, even when we grant them their energy use projections, always rely on over optimistic capacity factors, high-voltage lines acceptance, storage efficiencies. It means that today some technology is lacking and/or that some energy is missing. It does not bode well for the success of such strategies.
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Post by anonposter on May 23, 2012 16:35:24 GMT 9.5
10 billion people is a worst case scenario. It still won't be much below that (and it is a good idea to come up with plans which will work in the worse case). and energy use per capita can and must shrink. Wrong, it can only shrink if we accept a lower standard of living which is not something humans will do and we have enough Uranium and Thorium to support a much larger population than even that 10 billion worst case for millions of years at higher per capita energy usage than today so there's no reason why it even should shrink. Of course if you're going to insist on renewables then you'll need to get per capita energy usage down (as well as get rid of the expectation that the electricity grid will be reliable), but the public would much rather not accept a lower standard of living. the growing sectors of alternative energy are biofuels, We'll need the land for growing food for humans, not SUVs, there are also some pretty serious air pollution problems with many biofuels which justify phasing them out. To put things simply if you want any forests left you'll oppose large scale use of biofuels. wind and photovoltaics. 20% can be easily achieved and most countries (that want to) will move beyond 20% in the next few years. There is no evidence that even 20% is possible for those sources, so far the highest percentages of those sources have been in European countries where they could rely on their neighbours with hydro and nuclear to take up the slack. Whether the European grid could actually cope with having 20% of its capacity in wind and PV is still an open question. At the very least they don't seem to be helping all that much, once you move beyond what hydro can back up you're left with methane burning (and it's the methane which actually provides the electricity with the solar panels or wind turbines just providing some photos for electricity company PR brochures). Then why can't they show a country which gets close to 100% of their electricity from non-hydro renewable sources? It's almost as if they've just calculated how much energy is available on Earth without bothering with how it'll be used. I think it is not fair to use such an argument. In essence, you are saying that it has never been done and that proves that will be impossible forever. The fact is that is no proof. Before nuclear power appeared, no one was using it, so it should have meant it was impossible to provide most of electricity out of it. Yet it is in fact possible, as the case of France (and Lithuania ) demonstrates. The burden of proof for the claim that intermittent sources can run a country is on those who claim they can and they have not met that burden of proof (that nuclear has been able to provide most of the electricity on a grid has indeed been proven, though there are also theoretical reasons why one would expect nuclear to be able to do it (e.g. actually being reliable)). Besides, when you consider how much has been invested in non-hydro renewables if it were possible to run a country mostly on them someone should have done it by now (as France has with nuclear) or at least be a lot closer than Denmark has managed to get. But then again, it does not prove it won't work. It may mean it's not the easiest path or that some elements are missing. No, but the burden of proof isn't on me to prove it doesn't work, it's on those who think it does to show that it can work and I've seen nothing which indicates that we have the technology to make such a Rube Goldberg like grid actually work. Thus, I think it is important to look into the "100% renewables" scenarios to see what's actually missing and if it's possible that things will improve in the medium term (that is: before it's too late). What is missing is a sufficiently large scale energy storage system (and for Europe actually being able to collect enough energy, it has already been shown that Europe does not have enough renewable energy available to be 100% domestic renewables [Chapter 30 of Sustainable Energy without the hot air]). With present technology the choice is nuclear or fossil fuels, choosing renewable energy means choosing fossil fuels (because it'll be methane which backs them up). To summarize, it seems to me that 100% renewables scenarios, even when we grant them their energy use projections, always rely on over optimistic capacity factors, high-voltage lines acceptance, storage efficiencies. It means that today some technology is lacking and/or that some energy is missing. It does not bode well for the success of such strategies. That does appear to be the case (and their energy use projections are utter nonsense as well, it's almost as if their industrial policy were straight from Morgenthau). Whilst on a global scale the planet has enough renewable energy to run our civilisation if we could just capture it, on a regional scale many of the most densely populated regions just don't have the renewable energy they need and even for the areas which do have enough renewable energy available (e.g. Australia and North America) our current energy storage technologies just aren't up to the task (and I can't see us getting any which will be becoming available soon). I suspect the best hope for renewable energy will be space solar which won't have the reliability issues of ground based solar (and the rectenna used to receive the power is just a grid which lets light and rainfall through to the land underneath).
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Post by Bern on May 23, 2012 18:33:00 GMT 9.5
Wrong, it can only shrink if we accept a lower standard of living which is not something humans will do Just to take the example of electricity usage (yes, I know it's not total energy usage...) Average per-capita electricity usage in the United States was 4,585.625 kWh per capita in 2005. My three-person household, here in Brisbane, Australia (which I don't think is particularly energy-efficient - there are several key areas for improvement I'm actively pursuing) uses ~1,700 kWh per person per year. Nearly 3,000 kWh per capita per annum is hardly negligible (~900 TWh annually for the US), and I'd argue that my standard of living is pretty good, thank you very much. We have multiple computers, big screen TVs, all electric kitchen appliances (no gas - which also means electric heating / cooling), & air-conditioning. I don't expect the yanks to give up all their luxuries, but I think the point is clear - there are *large* savings to be made from energy efficiency that will have zero or negligible impacts on standard of living (some of them would arguably significantly improve it!). Don't even get me started on the topic of passenger vehicle fuel efficiency...
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Post by anonposter on May 23, 2012 19:32:37 GMT 9.5
Wrong, it can only shrink if we accept a lower standard of living which is not something humans will do Just to take the example of electricity usage (yes, I know it's not total energy usage...) Average per-capita electricity usage in the United States was 4,585.625 kWh per capita in 2005. My three-person household, here in Brisbane, Australia (which I don't think is particularly energy-efficient - there are several key areas for improvement I'm actively pursuing) uses ~1,700 kWh per person per year. What about the electricity of the shops you go to or the place you work at? What about the factories that produce all the stuff you use (OK, some of them are in China, but there's still some manufacturing done in Australia)? The per capita electricity usage figures are derived by dividing total electricity use by population, that means they include industry as well as residential (which is all you see on your electricity bill, even if it is only a small proportion of the electricity counted as part of the per capita consumption figure). I don't expect the yanks to give up all their luxuries, but I think the point is clear - there are *large* savings to be made from energy efficiency that will have zero or negligible impacts on standard of living (some of them would arguably significantly improve it!). You probably aren't using all that much less energy than the average yank (per capita electricity consumption of Australia isn't that much less than the US anyway) and given you don't have methane pipes you might actually be using a bit more than most of them. Looking at the wikipedia list of countries by electricity consumption sorted by per capita it appears that the lowest among countries where the majority would actually have a good standard of living it does not appear as if you could get much below 500 W person -1 and even then you'd probably have to use other fuels for heating and cooking (with associated problems they cause) and would probably also have less industry (i.e. less jobs). Though increased energy efficiency is worth aiming for, it just isn't the solution to global warming (or even a part of it, Jevons paradox is waiting). There's also a limit to how far you can take energy efficiency. Don't even get me started on the topic of passenger vehicle fuel efficiency... Why should they be fuel efficient if fuel is as cheap as it is now? If you want that problem solved raising fuel taxes is the way to do it. Oh and I think www.fuelsaving.info/defence.htm is worth a read, the car industry makes what people will buy (and car companies suffer when they don't).
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Post by max on May 23, 2012 19:44:51 GMT 9.5
It is conceivable to reduce the overall amount of energy used, for example by constructing houses so that they require only minimal cooling/heating, switching to heat pumps and electrifiying transportation.
While we would see an overall reduction in energy consumption in such a scenario, there would be a massive increase in the use of electricity, which makes it even harder for renewables to cover a large share of production.
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Post by anonposter on May 23, 2012 20:33:45 GMT 9.5
It is conceivable to reduce the overall amount of energy used, for example by constructing houses so that they require only minimal cooling/heating, switching to heat pumps and electrifiying transportation. Even then you'd still have a lot more people using energy which is going to increase overall consumption. Then there's the likely need for desalination which is a big energy user (it's a large part of why the middle eastern countries have such gigantic per capita energy consumptions). While we would see an overall reduction in energy consumption in such a scenario, there would be a massive increase in the use of electricity, which makes it even harder for renewables to cover a large share of production. Very much true, though I'd be surprised if we actually do get a reduction in energy consumption (maybe some reduction in per capita consumption in the places which use the most, but even then energy is the ability to do work and so something we'll always want more of if we can get it).
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Post by sod on May 24, 2012 7:02:29 GMT 9.5
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Post by Janne M. Korhonen on May 24, 2012 14:35:35 GMT 9.5
in general i find it hard to argue with a position that claims that conservation is impossible (when passive houses and lower energy use per capita prove that it is possible). I doubt many would claim that conservation is impossible. What I and many others do claim, however, is that even stopping the growth of energy demand (and in particular, demand for high quality, low entropy form of it known as electricity) will be very difficult with any means available in a democratic society as we currently understand it. Halving energy demand from current levels sounds, quite frankly, insanely optimistic assumption. That, or it assumes political developments that I, for one, would not want to see.
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Post by proteos on May 24, 2012 19:18:32 GMT 9.5
I doubt many would claim that conservation is impossible. What I and many others do claim, however, is that even stopping the growth of energy demand (and in particular, demand for high quality, low entropy form of it known as electricity) will be very difficult with any means available in a democratic society as we currently understand it. Halving energy demand from current levels sounds, quite frankly, insanely optimistic assumption. That, or it assumes political developments that I, for one, would not want to see. I completely agree with that view. Energy conservation requires investments, and these would get done only if it makes economic sense. At today's fuel prices, this is questionnable. We should also compare these investments to other investments in production facilities. The 100% renewables scenario thus imply that energy prices will go through the roof. Yet, we see many people complaining about energy prices today ... The alternative is rationing. This does not appear to be compatible with peace-time democracy.
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Post by anonposter on May 24, 2012 22:01:49 GMT 9.5
in Denmark 2011, Wind power contributed 28% to electricity supply. Actually it didn't, it contributed to the Norwegian and Swedish grids where it allowed them to throttle down their hydro plants for a time (Denmark sold the wind power very cheaply, then they bought the hydro power for a lot more when the wind died down). Thus why it doesn't show that a country can be powered on Wind, because the rest of Europe is having to make up for the unreliability of the wind. and talking about sources, is "‘Sustainable Energy – Without The Hot Air’" really considered to be a useful source? I've yet to see anyone actually find anything seriously wrong with it which makes renewables look better than presented in there (I personally think he is being far too kind to renewable energy and that he has stretched things quite a bit to try to make them work, I also think he has an over-optimistic view of demand management and managing intermittent sources). i have serious doubts about the wind power chapter. I just reread his wind chapter and can't see anything at all wrong with it. I can not see any serious error made (he does compare his theoretical performance with an actual wind farm as well and that wind farm does perform about as well as the figures he uses). I'd suggest looking at page 107 of the pdf where he compares his figures for renewable energy with other analyses (and where his figures happen to be a lot higher than what anyone else has come up with, that's a pretty good sign that he was being exceedingly generous). Which shows some very serious misunderstandings such as ignoring that the figures for wind he presents are realistic (i.e. were tested against a real wind farm which performed about as well, thus there's no reason to assume that there is anything at all wrong with them as they match reality). in general i find it hard to argue with a position that claims that conservation is impossible (when passive houses and lower energy use per capita prove that it is possible). The question in not whether it's possible, it's whether it's possible in a democracy and also whether we can reduce energy demand enough to avoid nuclear. I contend that the answers to both questions are mostly no (even if you reduce the energy usage of a house for heating and cooling to almost zero all you'll end up doing is allowing the occupants to spend more money on other energy uses). But anyway, even halving per capita energy consumption in developed countries (which itself seems unlikely) is still going to see massive increases in energy demand because those in developing countries are going to want more energy (how else can you do more work?). One thing I suspect a lot of ideological greens get tripped up on is to assume that the average person is going to be doing energy conservation for the sake of reducing their energy usage when that simply isn't true (energy is ability to do work, thus the average person is going to want to use it, not conserve it). I doubt many would claim that conservation is impossible. What I and many others do claim, however, is that even stopping the growth of energy demand (and in particular, demand for high quality, low entropy form of it known as electricity) will be very difficult with any means available in a democratic society as we currently understand it. Halving energy demand from current levels sounds, quite frankly, insanely optimistic assumption. That, or it assumes political developments that I, for one, would not want to see. I would have to agree with this. Looking at the per capita energy consumption list on wikipedia none the countries I could stand living in have per capita energy consumption much below half of Australia's which seems to set a lower limit to how low you can go and still maintain an acceptable standard of living. Of course as an adherent of White's law I wouldn't want energy consumption to go down. I completely agree with that view. Energy conservation requires investments, and these would get done only if it makes economic sense. At today's fuel prices, this is questionnable. We should also compare these investments to other investments in production facilities. That mainly applies to industry (homeowners seem to have a real love affair for incandescent heaters, which you won't find in many office blocks), although industry happens to be a big energy user. The 100% renewables scenario thus imply that energy prices will go through the roof. Yet, we see many people complaining about energy prices today ... The alternative is rationing. This does not appear to be compatible with peace-time democracy. Rationing of petrol (or as the yanks call it, gasoline) was done during the Arab oil crisis (and managed to cause violence). You could probably sustain rationing for a short period of time but I doubt a democracy could do it for decades and there'd be a lot of people getting around it (black market in electricity, stealing from neighbours (which is known to happen in the third world), cracking 'smart' meters, illegal logging, burning waste motor oil, etc).
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Post by proteos on May 25, 2012 7:17:27 GMT 9.5
That mainly applies to industry (homeowners seem to have a real love affair for incandescent heaters, which you won't find in many office blocks), although industry happens to be a big energy user. Of course, businesses are much more rational when it comes to money. After all, the point of any business is to make money to pay the people working there and that provided the capital. But individuals also encounter collective action problems. There is often the problem of the diverging interests of landlords and tenants. The boiler example illustrates this. It's most often the responsibility of the landlord to provide a boiler, yet an efficient one does not give him the possibility to set a higher rent, so all benefits go to the tenant. So the boiler change does not happen.
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Post by anonposter on May 25, 2012 22:09:07 GMT 9.5
But individuals also encounter collective action problems. There is often the problem of the diverging interests of landlords and tenants. The boiler example illustrates this. It's most often the responsibility of the landlord to provide a boiler, yet an efficient one does not give him the possibility to set a higher rent, so all benefits go to the tenant. So the boiler change does not happen. For fixed equipment which a tenant can't bring with them (e.g. boilers, among other things) that'll be a difficult problem to solve. Having the tenant provide more of the appliances would help but there are some things (e.g. heating, air conditioning, oven and stove, hot water) which you really can't expect a tenant to bring themselves, there are companies which rent out appliances to those who can't afford to buy them up front so for the fridge, washing machine, big screen TV, etc the tenant could supply their own (and also have an incentive to pay a bit more for something more efficient). Having the landlord pay the utility bill would work at encouraging landlords to buy more efficient appliances, but it would also work at encouraging the tenant to use them as much as possible.
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Post by sod on May 27, 2012 6:23:45 GMT 9.5
I agree, there will be serious political problems on the way to 100% renewables. i simply can t say whether we will really reach something like 95% till 2050 (if we try hard) or whether we get stuck at something between 50% and 60% because of a lack of storage, price issues or simply oversupply of cheap fossil fuels. but there are some facts that can t be ignored. 30+% is easily achievable. Denmark clearly demonstrates this. en.wikipedia.org/wiki/Wind_power_in_Denmark(it is irrelevant, whether this electricity is used in Denmark or not. Alternative energy does of course require bigger than national grids and more flexibility. it is also irrelevant from a theoretical "is it possible" kind of approach, like done in "..without hot air") at the same time we have been shown recently, that this amount of alternative energy can be run without significant additional back-up. This has been demonstrated in Japan, where a loss of 25% to 30% of electricity supply could be handled by the grid and flexible demand policies. en.wikipedia.org/wiki/Electricity_sector_in_Japanthe only real blackout problems foreseen in Japan are summer peaks, which can be easily controlled by solar alone, as Germany demonstrates by reaching a new peak of 22000 MW solar yesterday. www.focus.de/wissen/technik/solaranlagen-liefern-20-000-megawatt-produktion-von-solarstrom-erreicht-neuen-rekord_aid_758837.html
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Post by anonposter on May 27, 2012 7:17:29 GMT 9.5
I agree, there will be serious political problems on the way to 100% renewables. I'm more concerned with the technical problems, including the very real possibility that it isn't even possible to do it. Though renewables on that kind of scale are actually liking to suffer more political problems than nuclear due to the lower power density requiring them to be in more backyards and some of them being rather annoying (wind turbines produce annoying noise when operating and also a strobe light effect at certain times of the day, something I wouldn't want to put up with). i simply can t say whether we will really reach something like 95% till 2050 (if we try hard) or whether we get stuck at something between 50% and 60% because of a lack of storage, price issues or simply oversupply of cheap fossil fuels. I'd be surprised if anyone even reached 50% non-hydro renewable without extensive connections to neighbours who don't follow such lunacy and who are willing to provide the spinning reserve needed to cope (for a price of course, Denmark's wind power programme has been a disaster for Denmark, but a nice little earner for Norway). Denmark also has very expensive electricity and only achieves it because they can use the European grid to back up their unreliable wind farms, cut Denmark off from their neighbours and then see how well their electricity grid would cope. (it is irrelevant, whether this electricity is used in Denmark or not. Alternative energy does of course require bigger than national grids and more flexibility. How the electricity is used is relevant to whether it'd scale up to ≈30% of the European grid. it is also irrelevant from a theoretical "is it possible" kind of approach, like done in "..without hot air") Yes, but that's because the theoretical approach used in without hot air was only asking about whether the energy was even there to be harvested, much less how much the grid could actually handle (and showed that Europe doesn't have enough). at the same time we have been shown recently, that this amount of alternative energy can be run without significant additional back-up. This has been demonstrated in Japan, where a loss of 25% to 30% of electricity supply could be handled by the grid and flexible demand policies. Demand went down and CO 2 emissions went up, thus providing a good example of why nuclear power plants shouldn't be shut down unnecessarily (Germany's coal expansion is also a good example). thingsworsethannuclearpower.blogspot.com.au/2012/04/10-conservation-nuclear-still-lot-more.htmlJapan didn't cope with the shut down of their nuclear plants by moving to renewables, they coped by burning more fossil fuels. the only real blackout problems foreseen in Japan are summer peaks, which can be easily controlled by solar alone, as Germany demonstrates by reaching a new peak of 22000 MW solar yesterday. Never mind that solar peaks a bit earlier than the summer electricity usage peak (nor that electricity use tends to be higher in winter when solar doesn't work as well). Realistically if they don't restart their reactors they'll just end up building more gas peakers.
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Post by proteos on May 27, 2012 7:26:03 GMT 9.5
it is irrelevant, whether this electricity is used in Denmark or not. Alternative energy does of course require bigger than national grids and more flexibility. it is also irrelevant from a theoretical "is it possible" kind of approach, like done in "..without hot air" I disagree: that the electricity made in Denmark is consumed in Denmark has some importance. Because it's subsidized and has a marginal price of 0, people will pay the production whether they are using it or not, yet any surplus will yield no revenue. People will end up balking at paying for something other people are using and from which they are not getting any profit. Again, it's a collective action problem. These problems are real and should not be taken lightly. To really succeed, Denmark will have to find a way to absorb more of its wind power. Maybe storage in the form of heat will help in winter. Denmark is also a small country, so high voltage lines coming from other countries may supply the whole consumption. It is not true of bigger countries such as Germany, France, let alone Europe taken as a whole. The bigger the area, the smaller the relative capacity to export or import. And even at the scale of Europe, wind is not a reliable source of power (see this analysis from real production data, p16). The scenarios posted on the very website of the german ministry for environment show that, if storage is not domestic, Germany will need to import its whole consumption. This is nonsensical. A transmission capacity of 45GW between Norway and Denmark will represent a nearly 50x increase over the present situation. And even if storage is domestic, the transmission capacity problem will happen domestically.
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Post by sod on May 28, 2012 6:32:31 GMT 9.5
sorry, but is disagree. Your demand that Denmark must use its own wind power is seriously stacking the odds against this type of energy. (excluding water power also is one of these tricks) the nature of wind and solar demand for bigger grids. Solar will be used to the north and east and west of where it is produced. wind power will start to flow from coast to inland, with off-shore becoming a major player. water power storage is mostly possible in mountain area. a pure national view is a serious handicap under such circumstances. Would you folks accept the same limit for a look at fossil or nuclear power? (so all uranium needed has to be produced in the country, as well as all oil? how would this change cost comparisons?) ---------------------- but of course i know, that at the end not all countries can simply export their excess wind power. so at some point we will need serious storage, but that point might only happen beyond 30%. i really like the source you gave me: pfbach.dk/firma_pfb/statistical_survey_2011.pdfi think there is some really good news inside it, for example the low correlation between Ireland/GB and denmark/Germany wind power. (page 14) i am also seriously impressed by the weekly data of wind in Denmark. (yellow graph at the end of page 6) Weekly wind power barely drops below 1/3 of the top weekly power. (in contrast to the situation in Japan, we would not need the permanent "back-up" by fossil fuels but only a very temporary one...) also France is producing pretty high minimum wind power numbers. (table page 13) ---------------------------- Finally i want to make a comparison to "... without the hot air". here you can see his estimate of wind power potentials: (chapter 18) www.inference.phy.cam.ac.uk/withouthotair/c18/page_103.shtmlMacKay gives an estimate of off-shore having about 2.5 times of onshore wind (in the graph just called "wind") in GB. but when we look at denmark today, we see this numbers: "The installed wind power capacity in Denmark in service throughout 2010 was 3,749 MW of which 868 MW was offshore capacity." (page 11) pfbach.dk/firma_pfb/statistical_survey_2011.pdfand these numbers already produce about 30% of electricity need in Denmark. (for the comparison with MacKay it is totally irrelevant, whether the power is used in Denmark..) so either the onshore to off-shore potentials are completely different in Denmark, or there are some vast options, possibly 100% wind... (again from a pure theoretical "MacKay approach")
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Post by anonposter on May 28, 2012 7:59:41 GMT 9.5
sorry, but is disagree. Your demand that Denmark must use its own wind power is seriously stacking the odds against this type of energy. No, it's demanding to see some evidence that it actually works well enough to be worth trying. (excluding water power also is one of these tricks) We're not excluding hydro (it's the one renewable that's actually worth having, though geothermal can also be useful if the geology is right for it, e.g. Iceland). But wind is not hydro (and we do accept that if you've got the right geology you can indeed be pretty much 100% renewable like Norway and Iceland (which also uses quite a bit of geothermal), just that very few countries have enough rivers available to dam). the nature of wind and solar demand for bigger grids. Solar will be used to the north and east and west of where it is produced. How much bigger do the grids need to be? Do we need a HVDC line from Australia to the US? I would say that the nature of wind and terrestrial solar prevent either from being useful on an electricity grid (but if you want to talk big grids, how about more than 36,000 km from power plant to user for any grid using space solar?). wind power will start to flow from coast to inland, with off-shore becoming a major player. So what happens when the wind dies down all across Europe? It isn't unheard of. water power storage is mostly possible in mountain area. There isn't enough to back up all those wind farms and solar collectors you want. a pure national view is a serious handicap under such circumstances. Would you folks accept the same limit for a look at fossil or nuclear power? (so all uranium needed has to be produced in the country, as well as all oil? how would this change cost comparisons?) Fossil fuels and nuclear power have already shown the ability to do exactly that. But it isn't so much the national view that is the big one but the fact that no electricity grid anywhere has ever had 30% wind and from what we can tell from how Denmark has been operating it's nearly 30% wind it does not appear that they would have been able to manage had their subgrid been disconnected from the European grid (OTOH France gets about 80% of its electricity from nuclear, how lower per capita CO 2 and electricity prices than Denmark and would cope just fine if the interconnects with the rest of Europe were shut down (whether the rest of Europe would cope is another matter)). but of course i know, that at the end not all countries can simply export their excess wind power. so at some point we will need serious storage, but that point might only happen beyond 30%. In practice once hydro back up is exhausted it's methane (in open cycle gas turbines, you'd probably get more CO 2 emissions reduction by switching to more efficient (but not as good at load following) combined cycle and selling the bird blenders for scarp). i am also seriously impressed by the weekly data of wind in Denmark. (yellow graph at the end of page 6) Weekly wind power barely drops below 1/3 of the top weekly power. (in contrast to the situation in Japan, we would not need the permanent "back-up" by fossil fuels but only a very temporary one...) The problem though is that every so often it will drop to next to nothing and you need to have capacity ready to step in pretty much instantly when that happens, once you run out of hydro it means you'll keep fossil fuel burners at standby (and they'll have to running burning fuel all that time to be ready to step in instantly) and you'll also need to have almost complete spinning reserve. Here's a quote from pp. 187–188 of Sustainable Energy without the hot air: The UK is a bit larger than Ireland, but the same problem holds there too. Between October 2006 and February 2007 there were 17 days when the output from Britain’s 1632 windmills was less than 10% of their capacity. During that period there were five days when output was less than 5% and one day when it was only 2%. and these numbers already produce about 30% of electricity need in Denmark. (for the comparison with MacKay it is totally irrelevant, whether the power is used in Denmark..) so either the onshore to off-shore potentials are completely different in Denmark, or there are some vast options, possibly 100% wind... (again from a pure theoretical "MacKay approach") Denmark is not the UK (it doesn't have as many people for one thing), nor is it Europe as a whole. One other thing worth noting is that the best sites for wind turbines get used first so as wind power penetration increases you'll find that the sites left to develop aren't as good (it's one of the reasons Denmark's wind turbines have such lousy capacity factors).
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Post by sod on May 28, 2012 18:50:37 GMT 9.5
no wind in europe is actually unheard of. pfbach.dk/firma_pfb/statistical_survey_2011.pdfpage 16 shows that windpower in the 5 countries of this study barely dropped below 5000MW and never below 1069Mw for over 24 hours. ------------- i already answered the question about back up: there was enough backup in japan, to replace 30% nuclear power for a long period of time. (we are talking months by now) And this happened with little to no preparation at all. ------------------ you should compare you relability of wind power numbers from "Sustainable Energy without the hot air" with the numbers given in the paper for even only 5 countries: (page 16) pfbach.dk/firma_pfb/statistical_survey_2011.pdf reliability is about doubled in a comparison between GB+Ire and the 5 countries including germany, denmark and France! --------------- Finally, the numbers given in "Sustainable Energy without the hot air" are per person. www.inference.phy.cam.ac.uk/withouthotair/c18/page_103.shtmlso you can compare denmark to GB, like i did above. as can be seen on page 11, Denmark has 3 times more installed capacity onshore than offshore. (perhaps the ratio of produced power will be 2 to 1 due to higher capacity off-shore ) so according to "Sustainable Energy without the hot air", we should expect a potential of about 5 times more off-shore power in Denmark, which would nearly triple the power from wind., leaving us with something about 80% to 90% wind alone. (as share of electricity used). that is pretty close to 100% alternative energy. at least to me it looks like that...
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Post by proteos on May 29, 2012 5:15:49 GMT 9.5
sorry, but is disagree. Your demand that Denmark must use its own wind power is seriously stacking the odds against this type of energy. (excluding water power also is one of these tricks) the nature of wind and solar demand for bigger grids. Solar will be used to the north and east and west of where it is produced. wind power will start to flow from coast to inland, with off-shore becoming a major player. water power storage is mostly possible in mountain area. Don't get me wrong. I'm not against electricity trading with structural importers and exporters or even seasonal or daily ones. What I am trying to point is the special nature of the subsidized forms of electricity and also of fatal sources of electricity. When you subsidize one particular form of energy, with an unlimited buying mandate, you set the marginal cost to -∞. The grid operator is forced to take your electricity whatever the consequences elsewhere, and to dispose of it whatever the costs (but generally electricity has a positive price). Of course, the buying mandate is always limited by grid security, and thus the grid operator would have the authority to refuse the electricity while still paying the mandated price. But it will not get anything out of it. Thus any surplus (ie production > consumption) of subsidized electricity has a marginal price of 0. A consequence is that it is sold abroad for a price of 0 in case of surplus. It's the same for fatal sources of electricity: the marginal cost is 0, so if it covers the entire consumption, the price on a perfect competition market is 0. So the price of electricty exported is 0. Note that CHP produces fatal electricity in winter, as facilities are run because of the outside temperature, the electricity is a byproduct. Note that the situation is different for nuclear power. As nuclear reactors are essentially under the control of the owner, if the price comes to be under some price ceiling, generally > 0, the owner will stop making electricity. So the exports will (nearly) always cover some of the costs incurred (but maybe not all!). For dam lakes, it's even better: they are called to answer some increase in demand, so they always get a good price! In both cases, the outside world pays something for the power exported. It allows the France-Switzerland-Italy triad to operate in a stable fashion. France exports directly to Switzerland and Italy. Switzerland stores energy behind dams, and sell it at the right time to Italy. Everyone gets something out of it. Denmark gets nothing when wind power (and CHP) is in excess. In essence, the Danes are paying the whole costs of facilities of which they use only a part. My point is that it is an unstable situation if the costs incurred go too high. It would be perfectly good if excess wind power could be exported for a fair price, yet the economics make this impossible. There are solutions to this: the Norvegians could pay a part of the wind costs, but they have no incentive to do it (after all, electricity production is nearly 100% renewables in Norway!). So the Danes face an unpleasant choice: subsidizing foreign consumers by encouraging wind and fossil CHP at the same time or doing something else. Like storing/using themselves the electricity produced in excess in some form. And there note that I did not invent the heat storage idea: instead I fished it on the same website where I found the statistical analysis. And using wind power to produce heat in winter will immediately displace fossil fuels in Denmark! As I said before, do not dismiss collective action problems or fairness issues to quickly: these are real problems. We can't expect the Danes to produce free electricity for Norway to use. But this is already happening now, so something will have to give. Either wind power will not reach higher penetration or domestic uses will be developped. That's how I see things.
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Post by anonposter on May 29, 2012 5:50:57 GMT 9.5
i already answered the question about back up: there was enough backup in japan, to replace 30% nuclear power for a long period of time. (we are talking months by now) And this happened with little to no preparation at all. Yes there was (almost, they did have to reduce demand to do it) but they also increased their CO 2 emissions so it isn't an example of how a low carbon grid could work. Besides, all it proved was that if you lose 30% of your capacity you can make it up by burning more fossil fuels, is that really how you plan on dealing with the unreliability of wind power? reliability is about doubled in a comparison between GB+Ire and the 5 countries including germany, denmark and France! Doubling reliability is still unacceptably bad. Finally, the numbers given in "Sustainable Energy without the hot air" are per person. They are per person living in the UK. as can be seen on page 11, Denmark has 3 times more installed capacity onshore than offshore. (perhaps the ratio of produced power will be 2 to 1 due to higher capacity off-shore ) so according to "Sustainable Energy without the hot air", we should expect a potential of about 5 times more off-shore power in Denmark, which would nearly triple the power from wind., leaving us with something about 80% to 90% wind alone. (as share of electricity used). that is pretty close to 100% alternative energy. at least to me it looks like that... Never mind that it'll all be dependant on their neighbours to provide backup power, getting a 100% renewable grid without it being 100% hydro and geothermal is likely impossible with current technology, no matter how much you may wish the world could do without nuclear and is so far unproven at the very least.
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Post by sod on May 31, 2012 20:43:40 GMT 9.5
proteos, i understand your concerns. i think there are many possible questions about alternative energy: can we reach 100%? of what? in an economically useful way? with high security of electricity supply? but i also think that there is a limit to which of these questions can be reasonably discussed on an online forum. (without doing high end scientific research) so i would focus on the question "is it theoretically possible to reach 100% with something close to current technology?" for a start. ("...without hot air" does something similar) and i think the cases of Denmark, the math from MacKay and the back-up power shown in Japan shows, that this is possible. www.inference.phy.cam.ac.uk/withouthotair/c18/page_103.shtmlfrom a practical point of view, 100% wind doesn t make any sense, of course. it would only provide 100% renewable on "average". so there would be excess power quite often and some times nearly none. (which would need fossil back up)
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Post by anonposter on Jun 1, 2012 8:30:26 GMT 9.5
from a practical point of view, 100% wind doesn t make any sense, of course. it would only provide 100% renewable on "average". so there would be excess power quite often and some times nearly none. (which would need fossil back up) If it needs fossil fuel backup then it's pretty much by definition unacceptable (it wouldn't be 100% renewable then would it?). When it comes down to it this whole crap about intermittent renewables is just a smokescreen to continue burning fossil fuels while shutting up those who are concerned about global warming (and it's working on a lot of people).
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Post by sod on Jun 2, 2012 5:02:01 GMT 9.5
100% renewable is 100% renewable.
a likely scenario looks like this: 100% of "conventional" electricity demand is met by renewables. but x% of real "conventional" electricity demand is actually covered by fossil gas back up. (until wind gas takes over)
but at the same time, the excess x% renewable electricity goes into the new electricity market, that the surplus had created: mostly fuelling electric cars (and possibly avoiding much more fossil fuel burning than the reserve gas plants actually do)
and again: what i did was just the same as "... without hot air" did: calculating theoretical possibilities. the outcome is clear: 100% renewables is doable with technology that exists today. even a completely inpractical 100% wind is doable in some countries, using the numbers provided by " .. without hot air". (links see above)
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Post by proteos on Jun 2, 2012 8:19:47 GMT 9.5
proteos, i understand your concerns. i think there are many possible questions about alternative energy: can we reach 100%? of what? in an economically useful way? with high security of electricity supply? but i also think that there is a limit to which of these questions can be reasonably discussed on an online forum. (without doing high end scientific research) so i would focus on the question "is it theoretically possible to reach 100% with something close to current technology?" for a start. ("...without hot air" does something similar) This quite true that a forum can't be the place to do real research. However, one can point to technical documents or data (such as those on the german ministry of environment website ;D ). The question of whether 100% renewables is already the subject of much litterature, generally for developped countries with a knack for renewables. I've only read personnally part of the studies for Germany. I've listed my concerns. The bottom line is that if we cover the entire North Sea and much of the land in Europe with wind turbines, manage to implement storage systems, manage to coerce/convince citizen to abide by demand management schemes and to accept lots of high voltage lines, this might be possible. The problem of these studies are the over optimistic assumption they make. Too high capacity factors, for example. Of course these facilities have to be economically self sustaining at some point. One can't save the world without making a living out of it. That's a major problem. Finally, a very difficult point for all these scenarios are the high voltage lines they require. If you require all the countries to be fully integrated with a lot of spare capacity in transmission most of the time, you need them. It is very difficult, sometimes downright impossible to build such lines in Europe because of citizen's opposition. As an example, since 1994, there has been a project to build a line between France and Spain (2GW both ways). It will open in 2014 and the costs have exploded. And it's not nearly enough to break the Iberic peninsula near-isolation. So I think that not only should we look at the physical possibility to have a 100% renewables system, but also at the practical feasability
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