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Science

Thermal Solar Plant To Be Erected In Australia 371

connect4 writes: "An article from the bulletin explaining a plan to erect a 1km high solar convection wind turbine in outback Victoria - the worlds tallest construction. Projected output per tower: 200MW. Cost to build: A$670m. Footprint of tower: 20sq km ."
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Thermal Solar Plant To Be Erected In Australia

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  • Wonderful! (Score:3, Informative)

    by Pete (big-pete) ( 253496 ) <peter_endean@hotmail.com> on Monday December 10, 2001 @06:52AM (#2681304)

    This sounds very impressive. It's great to hear that there is still plenty of active development in seeking out new power-sources. The tower sounds absolutely incredible:

    The lightweight concrete tower will be the diameter of the Melbourne Cricket Ground's playing surface at its base, and will reach a kilometre towards the sky. A vast, gently sloping greenhouse will extend from its base to a radius of 2.5km, funnelling a rising column of hot air through 32 wind turbines about 40m above ground, generating power day and night.

    If it's built it will surely be a wonder of the modern world - I'd certainly love to see it! A prime example of the better elements of what mankind is capable of...

    Also there is always an environmental issue, even in solar power it is common for there to be MORE damage to the environment at first - in this case they expect to have countered that, and be "in the black" environmentally after only 2 1/2 years!

    -- Pete.

    • Except, of course, for the permanent existence of a 1 km tall concrete tower occupying 20 sq km of land...
      • Re:Wonderful! (Score:3, Insightful)

        by sql*kitten ( 1359 )
        Except, of course, for the permanent existence of a 1 km tall concrete tower occupying 20 sq km of land...

        That bit of Australia is kinda flat anyway. I'm sure the top could be used for other stuff, like comms or even stellar observation, which should work really well with little ambient light pollution, and relatively clean air. It would also be a massive tourist attraction, especially if the greenhouses could be cultivated.

        Plus, you'd be able to see airliners coming from a long way off. Sadly, you gotta think about that whenever you talk about tall structures these days.
        • Re:Wonderful! (Score:3, Informative)

          by zmooc ( 33175 )
          Well I don't think it would be very usefull for stellar observation. Probably the air that comes out of the chimney is relatively hot and will distort the light above the tower. But I might be wrong:)
        • Re:Wonderful! (Score:2, Insightful)

          by killmenow ( 184444 )

          ...and relatively clean air. It would also be a massive tourist attraction...
          There goes the clean air.
  • Projected output per tower: 200MW. Cost to build: A$670m. Footprint of tower: 20sq km. Look on the face of Trolls when they see "erect" in a /. headline: Priceless.
    • This tower is going to be 10km tall with a 20km footprint. It will need to be enclosed for thermal convection to be most efficient, too. So, my big question is: what are they doing with the huge surface area?

      A decent sized apartment would take up a 10x10x10 metre cube. If this tower were built in a place other than Australia, with a decently cold climate and still a lot of sun, it would be possible (and perhaps even cost-effective) to house a few million people in this solar-heated supertower.

      If architects were especially creative they could add areas for businesses and recreation, including fully-enclosed, solar-heated parks along the surface, too, to provide comfortable habitation for the millions living inside, while providing fresh air, entertainment, possibly even food production without its inhabitants ever needing to step outside.

      Unfortunately, after 9/11 I don't think people would flock very quickly to live in such a huge high-rise.

      How strong would a cone-shaped building be after a plane flew through one of its walls?
      • I was thinking more of an arcologie type setup. You've allread got the huge tower built. Anything that generates heat below the tower is a good thing. Turn the tower into the equivilent of a 1 km high sky scraper, fill it with apartments, cinemas, malls, etc as you suggested. Now take taht several kilometer skirt and use it as farm land. If heat is all you care about then using that land as a combination of parking lots and farm land will average out quite nicely and provide (hopefully) enough food to keep the inhabitants fairly self sustaining. Greenhouse conditions should extend the growing season somewhat as well.

        Of course, I could be talking out of my ass
      • Tower is 1km tall, not 10. The greenhouse works quite well. You can use something like 75% of the area under it for growing crops. Living in it is a interesting new idea...

        Oddly enough, urbanizing one of these would be like recycling energy. Any waste heat the 'city' produces from the generated electricity is used to heat the air and generate more electricity. You couldn't live anywhere near the base of the tower since the winds get quite impressive there. Heating bills would be nonexistent. Some politician moght get it into his head to outlaw air conditioning in the greenhouse, but that's stupid since the A/C is inefficient and the net effect is to raise the temperature even more.
  • More info (Score:4, Insightful)

    by Max von H. ( 19283 ) on Monday December 10, 2001 @06:58AM (#2681322)
    EnviroMission's site [enviromission.com.au] has more information regarding the technology employed, as well as some nice flash animations.

    Considering Australia's size and geography, I'm surprise solar power isn't implemented on a wider scale. If only the polititians would get their heads out of their arse, they would realize solar and wind power are the only intelligent, long-term choice. They may bitch about the price, but once these things get to be built in large quantities the price will go down accordingly.

    /max
    • Re:More info (Score:5, Informative)

      by Goonie ( 8651 ) <robert.merkel@b[ ... g ['ena' in gap]> on Monday December 10, 2001 @07:04AM (#2681334) Homepage
      This is why not:
      1. The Liberal and National parties, which currently form a coalition federal government, receive much of their funding from mining companies.
      2. The Labor Party, which is the major opposition party and controls most of the state governments around the nation right now, is an offshoot of the union movement. Guess in which industries the union movement is strong, and thus which unions exert considerable clout in the ALP? Yep, that's right, mining and electricity.
      • Re:More info (Score:4, Informative)

        by Nikau ( 531995 ) on Monday December 10, 2001 @09:46AM (#2681722) Homepage
        The Liberal and National parties, which currently form a coalition federal government, receive much of their funding from mining companies.

        That may be, but Australia is bound by the Kyoto protocol to control its emissions:

        But burning more brown coal would compromise Australia's obligation to reduce its greenhouse emissions under the Kyoto protocol, which requires it contain its emissions by 2010 to within an 8% increase of 1990 levels.
        So basically building the tower would help the emissions situation, since building the tower instead of another coal plant (another power plant seems inevitable judging by the article) will be hitting two birds with one stone... New power plant, no extra emissions.

        Also, we have this paragraph to consider as well:

        By 2010, Australia's energy supply companies must purchase 10% of their electricity from renewable sources. The figure is now 8%, most of it from hydro-electric power. Emerging solar technologies are likely to provide much of the 2% increase.
        Building another coal plant doesn't exactly help them reach this goal, now does it?

        The Labor Party, which is the major opposition party and controls most of the state governments around the nation right now, is an offshoot of the union movement. Guess in which industries the union movement is strong, and thus which unions exert considerable clout in the ALP? Yep, that's right, mining and electricity.

        OK, so the mining industry seems to have a chokehold on 80-90% of Australia's government. Whooptee-doo. What's the projected output of the tower? 200MW. According to the article, what's the overall output of Victoria's power plants?

        ...to replace Victoria's current 7672MW generation capacity.
        So... 200MW from a solar tower vs. 7672MW from mostly coal plants, and the mining industry feels threatened? And remember, this is just for Victoria and its vicinity, never mind the rest of Australia.

        I don't think the government or their mining industry friends need to worry. The government wants to build another plant to provide jobs, that's great. But building a solar tower will help Australia meet its other obligations, not to mention other benefits - tourism, potential farming opportunities in the greenhouse... I doubt there will be a sudden rush in the construction of the towers, but it'd be neat to see at least a few...

    • by SofaMan ( 454881 )
      Considering Australia's size and geography, I'm surprise solar power isn't implemented on a wider scale.

      Because the sun goes down.
  • by slashnik ( 181800 ) on Monday December 10, 2001 @06:59AM (#2681323)
    In a similar vein this report on the bbc

    http://news.bbc.co.uk/hi/english/uk/scotland/new si d_1699000/1699665.stm/

    says that wind energy in Scotland with the help of wave and tidal resources could provide 60GW / 75% of the UK's energy requirements.

    slashnik

    • by Richard Kirk ( 535523 ) on Monday December 10, 2001 @07:41AM (#2681406)
      The solar chimney is a really neat idea for reasons that do not transfer to wind power.

      All the moving bits are at the bottom (well - within 40M of the bottom). This means that you can get to service them without having to scale the chimney. You can swap out the generators for more efficient ones when they are developed without having to redesign the rest of the scheme.

      There are windmill designs (the Savonius rotor) that have the generator at the bottom, and don't need pointing into the wind, but these are a design compromise between efficieny and servicability. The wind farms in Scotland have a dynamo with a windmill on top of a big stick. I remember the 'Tomorrows World' presenter going up it, and going rather green: the really big ones are pretty scary places to work.

      The chimney can also generate power when it is half-built. It won't be as efficient, but this may allow the building loan to be spread out. Once you have built the chimney, it may then make finiancial sense to expand the greenhouse area. A windmill is either there or it isn't.

      Don't get me wrong - I like windmills, and a solar chimney in the Orkneys simply isn't on. However, the Orkneys windmill is paying because regular electricity was over 4 times the cost on the mainland. However, IMHO, the solar chimney is in a different league to windmills and tidal stations. I do hope it gets built.

    • Wind power is getting more viable as a power source every day. Small turbines are popping up throughout Scotland on remote farms, and near remote villages. Even the large power companies are building these, in order to avoid dragging costly power lines across long distances to relatively small groups of users.

      New turbines with outer cowlings to focus the wind through the turbine generate up to 40% more power size for size, and at wind speeds as low as 2 metres per second (5 is the normal cut off). See This New Scientist Special Report [newscientist.com].

      When I buy my 10 acres I'm going to stick a couple of these babies on 'high field' with the goats!
  • by Anonymous Coward on Monday December 10, 2001 @06:59AM (#2681324)
    Some questions that need to be considered:

    • Maintenance costs? I mean, you don't just whack a great big building in the middle of nowhere and expect it to just work for the rest of its life, do you?
    • Expected life span? If it only is good for ten years, it's a bloody expensive way to generate electricity.
    • Effect on the surrounding area? A one kilometer tower is going to cast a pretty damn big shadow.
    • Expected average output? 200 MW peak output is what the article says... that's not the same as 200 MW average.
    Don't get me wrong -- I reckon it's a rather neat idea. But the article doesn't give the whole story by any means.
    • You're right about the maintenance costs. This thing will have many turbines that will eventually need replacing. Probably not off-the-shelf parts, either.

      In California, where we put up hundreds of wind generators, a very large fraction of them are idle because they broke and are very expensive to fix. I expect the same problem for this thing. I only wish there were a practical system for generating solar power without moving parts, something you pay for once and use forever. Sigh...

      • The way I see it, the turbines in this plant are likely to be as reliable as a hydro-electric turbine.
        Hydro plants need dams, dams are big, destructive and (hopefully) very permanent.
        Hopefully, instead of making new hydro plants, we'll make these things (need a cool acronym)instead.
        • Well, not an acronym, but "Solar Chimney" already sounds pretty cool - they've actually been around since the 80s, though the oil companies used to do a good job of silencing people who talk about them in the mainstream press - I remember reading about plans for a pilot plant in Spain in 1984.
      • I only wish there were a practical system for generating solar power without moving parts

        They're called solar panels.

        Yes, they wear out, but they really aren't that expensive, especially now that they're being designed as roofing material (both shingles and metal sheet-style). Cost wise there's little advantage currently, installation and maintenance will currently cost you about the same as it would to get the power from the grid. Manufacturing costs for solar cells have steadily gone down, and will continue to do so in the forseeable future, while efficiencies rise. With a moderate storage system there's no worries about short-term power loss (obviously this isn't a great sollution for somewhere that gets a lot of snow). If you happen to be in a location where getting on grid is cheap and easy, you could hook up a phase-matching invertor and sell your excess power to the power company (at least in CA, one of the few benefits of deregulation). If you're in a location where getting on the grid is difficult or expensive, this is the way to go (I lived in such a situation for almost 20 years).

        In an urban or suburban situation it doesn't make much sense from an individual perpective, but a whole neighborhood with solar-cell roofing could produce a fair amount of power. There's no polution, no line-loss, and the only space that's used up isn't good for much else anyway.

        Really, all that's missing is an economic incentive for people to do it. At one time there was a tax credit for installing alternative energy systems (I don't know if it was Federal or State), and GWB's short-sighted energy plan unfortunately doesn't include that. (I applaud him for having an energy plan, I just don't think it's a very good one.)

        The lifecycle for the solar cells is 15-25 years, depending on the specific tech (the same as most standard roofing materials), the invertor you'd want to replace every 10 years (to take advantage of new tech, they generally last longer than that), and the batteries should probably be replaced every 5 years or so (we used deep cycle lead-acid batteries, Lithium or NiMH would probably be a better choice, but I don't know anything about the cost/maintenance issues).

    • Effect on the surrounding area? A one kilometer tower is going to cast a pretty damn big shadow.

      Solar power... solar clock. Can you say tourism? I wonder how many people would want to stand in the shadow at 4:20?
    • the Lions and other African animals being released on the new preserve in the Outback? Or, will they be used to protect it? Won't they get sucked up into this thing? I really don't want to see shredded lion and elephant meat spewing out of this thing like a fountain.
    • Maintenance costs would be on par with that of a hydro power plant. In other words, much less than a fossil fuel or nuclear plant.

      A big shadow, yes, most of that shadow is going to fall onto the surrounding greenhouse.

      Average of 200MW, yes. This thing works 24 hours a day. It doesn't generate quite as much (something like 70%) but then usage at night goes down as well.

      It is a neat idea, and I'm rather pissed off at that executive in the Wind power sector who dismissed it as "just a chimney" and claimed it won't work. Never mind that fact they built a smaller 20KW model in Spain a few years back that worked qutie well.
    • by Saeger ( 456549 )
      Maintenance costs? I mean, you don't just whack a great big building in the middle of nowhere and expect it to just work for the rest of its life, do you?

      From the article: "The Manzanares plant ran for seven years, with minimal tuning and maintenance, delivering electricity both night and day" -- and that was from a 20 year old prototype. I'd expect the aussies to do much better with current tech, despite the increased scale.

      Effect on the surrounding area? A one kilometer tower is going to cast a pretty damn big shadow.

      Does a bear shit in the woods? If a tower casts a shadow in the middle of the outback, and no one is around to see it, does it really cast a shadow? :)

      Population density in rural Victoria is what? .0001/km? And I don't think the kangaroos are going to complain. (I wonder how fast the shadow of the top of the tower would be moving along the ground? Could make a game of it.)

      Expected average output? 200 MW peak output is what the article says... that's not the same as 200 MW average.

      True. Also, these ugly "solar chimneys" aren't very efficient in terms of land area wasted per MW, when compared to every method of power generation. But then again, the aussies don't exactly have a better use for the land (aboriginals be damned).

      Hmm. Come to think of it, Eco-terrorists might eventually have a field day if too many of these were built.

      One silver lining, though, would be that at least we'd gain some experience building really tall towers, so that when we are finally able to manufacture ultrastrong carbon-based materials in a few years (like diamondoid), we'll have a headstart on building the "space elevators" we'll need to make solar power satellites, and spacedev in general, cost effective.

      --

  • by whanau ( 315267 ) on Monday December 10, 2001 @06:59AM (#2681325)
    $670 million australian isn't that much money.

    Currently its $348 million US, which is about the TOC of a nuclear reactor of the same capacity
    Throw in credits from carbon trading, valuable research into the technology, bragging rights and the ability
    to wean australia's fossil fuel dependant economy off foreign oil (australia is the world's worst polluter per captia) this is a very very good deal. Go Aussie!
    • by Grond ( 15515 ) on Monday December 10, 2001 @03:13PM (#2683305) Homepage
      whanau said:
      "Currently its $348 million US, which is about the TOC of a nuclear reactor of the same capacity."

      US$348 million will buy you a nuclear plant in the 1.5 Gigawatt range. It would cost about $300 million to build a new reactor comparable to the one about 5 miles from my house (Arkansas Nuclear One [entergy-nuclear.com]) which produces a total of 1694MW. Nuclear power is far, far cheaper than solar, wind, hydroelectric, you name it. Now, whether it's better is somewhat open to debate, but it is by far the most efficient way to produce really large amounts of electricity, both in terms of cost and in terms of space (the cooling tower on Unit 2 is big, but it ain't 1km big).
      • Were I to conceede that your prices were correct, I would still insist on factoring in the cost of the special law that the nuclear industry got exempting them from liability insurance (it's not QUITE that broad, so this is a smidgen unfair, but I don't remember the details).

        I understand that Lloyds was reluctant to cover them before they got their special "get out of jail free" card.
        .
  • This stuff could be VERY useful in near-tropical regions. like India for example, the temperature difference (in the more extreme parts ~25N) goes from 40deg C (in the daytime) to something like 10-15 at night. So this could also possibly be used to churn out far more power than the aussie counterpart, IF used correctly. This is specifically for regions that have a high temperature during day/night times, and a nice dry climate. Coastal regions wouldnt be of so much use for the simple reason that the temp. gradient obtained is not so large.
    • by maaaaanis ( 180232 ) on Monday December 10, 2001 @08:44AM (#2681558)
      Check a map of autralia...
      http://www.bom.gov.au/climate/averages/
      Notice the climate, it's got more tropical, near tropical, desert, savanna etc etc than any other country. Better still, it's bigger than india and has less than 1/50th of the population, more available space, if native title issues ever get sorted.
      In central australia there is an average of 11hrs sunlight a day all year which is the most important factor when using a greenhouse.
    • The idea is that the solar tower takes advantage of the vertical temperature gradient in the atmosphere. The day-night change in temperature wouldn't help you out there.

      The best places for this type of thing are tropical/subtropical deserts. Lots of sunshine, high temperatures, and dry weather.

      Hmmm, if Saudi Arabia gets moving on these things, they'll have lots of electricity to sell once the oil runs out!
  • A few points here:
    • On the plus side, a smaller version of this thing was built in spain, and worked.
    • On the minus side, I don't believe it's at all clear how this thing scales.
    • On the really minus side, Australia is no longer a country that has the sort of boldness it took to build the Snowy Mountain Irrigation Scheme in the 1950s, where rivers were reversed; nor the audaciousness to build the Sydney Opera House in the 1960s. It's unlikely this construction will ever happen, more's the pity.
      I think we've lost our nerve for risk, an affliction in which we are probably not alone.
  • agricultural tie-in (Score:3, Interesting)

    by Barbarian ( 9467 ) on Monday December 10, 2001 @07:03AM (#2681332)
    Could you use the large "greenhouse" below to grow something that would not normally be sustainable? I guess it would take a small amount of the energy out, but it might be worth it.

    If not, at least plant a forest, so that you have more heat capacity to work with over night when the sun is down.
    • Nice idea, but since the whole structure is nothing but a chimney you'll need some very storm-resistant tomatoes for that greenhouse ;)
      • I guess you didn't bother looking at the picture in the article. The chimney actually has a small footprint near the center of the large, circular greenhouse. The picture appears to show fields in the area covered by the greenhouse section. I imagine the winds are tend to pick up the closer one gets to the center but are only ferocious right under the intake to the chimney. I bet one could easily grow trees and/or crops everywhere but a small area right around the chimney intake.
    • The problem with this is water. The place where there putting this is a dry and arid region, for obvious reasons. If youre going to grow stuff in a 25km^2 greenhouse, thats going to need alot of irrigation. They mention in the article that there would be a cloud froming from water condensation at the top of the tower. It would be really interesting to harvest that water for use in the greenhouse. It would take awhile, but as long as you harvest enough water out of the air column, you could potentially make it sustainable. Plants release water, water is harvested by tower, water irrigates plants. Salt buildup would not be as much of a problem, since youre essentially using distilled water for your irrigation purposes. This would be a slow process, since the water input would be coming from condensed humidity in the air. The thing you would have to be most careful about is the fact that you dont want all the water that youve just worked so hard to caputure going back out the chimney because you cant condense it fast enough. It could be done though, very interesting idea.
      • If youre going to grow stuff in a 25km^2 greenhouse, thats going to need alot of irrigation. It's worse than that (assuming they're planning on placing it in desert regions) -- it's a 5km diameter (19.6 sq km, about 4,800 acres) greenhouse with a high velocity dry wind blowing through it continuously. Normal plant leaves lose a lot of water in those conditions. Cactus wouldn't, but why would Australia need greenhouses to grow cactus. You might recover part of the water from condensation near the top, but if the relative humidity was low to start with, 10 degrees C temperature drop isn't going to condense out nearly as much water as was put in to start with. If the intention is to modify the weather by injecting lots of moisture 1 km up, and the fresh waster is available, a row of these things would do it, besides growing veggies and generating power.

        Or maybe it wouldn't work at all if plants were in it, since the evaporation would cool the input air, and thus you wouldn't get the heat differential driving the chimney. On the other hand, water vapor is lighter than air, so would that maybe offset the cooling effect and keep the chimney going? I don't know how to calculate this...

        Finally, if evaporation is acceptable, you could make sea-coast green-house/towers double as desalinization plants. Run the seawater into ponds in the greenhouse to evaporate, capture part of the condensation in the tower...
      • It's probably too small, but something like this could increase the amount of sea-breeze, yielding an average increase in percipitation.

        But it's probably too small. Perhaps a forest of them would work. (OTOH, in California it takes the entire central valley to accomplish essentially that same thing, but the central valley isn't designed to force the air up. It just sort of does the job [when it's temperatures get over 100F.)
        .
    • The idea behind the green house must be to produce HOT air, to be swept up the chimney. Lots of lovely green stuff under the greenhouse would tend to cool the air, and would definitely add humidity. The cooling would definitely be bad. As someone else pointed out, there will be a condensation cloud at the top of the chimney. We wouldn't want that to be any bigger than necessary, as the cloud would further cool things, so the humidity might be bad too. By the way, that's a desert. Where is the water going to come from for these hypothetical plants?

      Here's another problem with the ``plant stuff in the greenhouse idea'': you use green houses for plants which can't grow in the cold outside climate. These greenhouse/tower contraptions are going to be most feasible in HOT climates, where these heat-loving plants grow naturally. Finally, the green house will be sucking in cold outside air. The plants near the outer edge might get MORE chilled at night than they would without the greenhouse (though the wind would prevent radiant cooling; this could be a big plus in high deserts).

      Probably the best idea would be to pave underneath the greenhouse, and periodically repaint the pavement black.

  • Why? Because all these enviromental generating schemes do is prevent the building of NEW fossil
    fuel stations. What never happens is the replacement of a fossil fuel power station with
    a renewable energy one. We need to reduce our overall power consumption. How many of you leave
    your PC switched on for no reason other than you can't be bothered to wait 1 min for it to boot
    when you want to use it again in 3 hours time?
    UNtil peoples free for all attitude to energy consumption changes all we'll be doing is buying
    ourselves a little bit more time but the end result of massive climate change will still occur.
    Building more nuclear plants would help but the liberal right-on lobby would have a apoplectic fit
    if anyone suggested that because in their not-too-bright minds they do a simplistic link between nuclear power and nuclear war so hence its verbotten.
    • Building more nuclear plants would help
      Australia can't affort to build and operate a nuclear plant - they are very expensive.

      Also, you all may recall the recent news that British Nuclear Fuels has liabilities of 48,000,000,000 pounds sterling (I think you still come close to doubling that for US dollars). After more than thirty years of operation of nuclear power in the UK the debts are astronomical and still growing.

      In the US, of course, the plants can break even by selling weapons materials at a cost calculated to keep them breaking even, which is why you only see nuclear power in countries that have nuclear weapons or aspire to do so.

      As for safe and clean, ask someone in the Ukrane about that! Also remember that the grossest mistakes of Russian engineering have been mirrored in the past by corner cutting US entrepenuers (Three Mile Island).

      • Three Mile Island

        FUD. What happened at TMI? Something went wrong with the reactor and then all of the safety measures worked perfectly. No one was hurt. No radiation was released. The only thing that went wrong at TMI was the senseless media frenzy.

        Chernobyl is a totally different situation. It was caused by porrly trained people performing a dangerous procedure they weren't supposed to be doing in a plant with hopeless safety features. The Chernobyl was a poorly designed reactor. End of story. Nuclear safety in the US is taken very seriously, and the reactors are designed to be robust, and fault-tolerant.

        • FUD. What happened at TMI?
          It was a good example of what happens when costs are cut and contractors rob the client. A contracting company was called in to do radiography on a series of welds. They examined one easily accesable weld, and changed the lead ID numbers on each of a few hundred films to make it appear that they had examined several hundred welds. There were not enough staff to check the work of the contractor, so even such an obvious scam remained undiscovered until a pipe leaked. It's hard to look down on the Russians when such things happen. Some may argue that all of this happened long ago and couldn't happen now, but economic rationalisation is more prevalent now than it was back them.
          The only thing that went wrong at TMI was the senseless media frenzy.
          The court decided differently.
          Chernobyl is a totally different situation. It was caused by porrly trained people performing a dangerous procedure
          You have of course heard of the recent incident in a US facility where enough high grade waste was stored in close enough proximity to start pumping out some serious radiation. The people there were poorly trained as well.

          Nuclear power was the shiny hope of the 1950's which didn't quite work out as expected. Ultimately there are cheaper and much, much safer ways to produce steam, and much better uses for radioactive materials than boiling water.

  • by hwilker ( 225377 ) on Monday December 10, 2001 @07:32AM (#2681392) Homepage
    It looks like the initiators of this project already thought about vested interests. These, rather than technical issues, are most often the biggest obstacles to overcome when trying to establish a totally new technology.

    The quote by an energy industry manager, "It won't work", is typical of the process:

    • At first, technical issues are put forward: "It won't work. If it would work, we would have done it before."
    • Then come economic issues. "It will be too expensive. Nobody will buy it."
    • If that doesn't work, and the project in question looks like it might succeed, political lobby work is started. "If it goes forward, we will fire so-and-so many workers. It must be forbidden."

    Usually, that is the end of things for revolutionary technologies... I hope it won't be in this case.

  • Comment removed based on user account deletion
  • Sounds great to me (Score:2, Informative)

    by musicmaster ( 237156 )
    Just for those who didn't read the text:

    They had a similar thing in Spain (150 km south of Madrid) between 1982 and 1989. It had had some funding problems and for that reason was built on the cheap. As a consequence it collapsed in 1989 in a storm. It had a capacity of 50KW.

    The idea is that:
    - you have a big greenhouse that collects the sun and generates hot air.
    - you send that air into a very high chimney because the air at a high altitude is colder so you can get more energy
    - closed water basins in the greenhouses store the heat for the night so that you can generate electricity at night too

    The biggest problem seems to me that the technology has not been tested very much. Scaling from 50KW to 200MW is quite a big step. And the quoted prices seem to have a lot of variation depending on the article that you read.
  • Carnot Efficiency? (Score:2, Informative)

    by mrright ( 301778 )
    This is a really nice project. But it only makes sense if it is combined with agriculture or other forms of solar power generation.

    The carnot efficiency is defined as e=(T1-T0)/T1. If we assume T1=20C=293K, T0=0C=273K, the maximum thermodynamic efficiency is 20/293=0.068=7%. And this is the theoretical maximum. So it would be more reasonable to expect something like 4% for the total efficiency.

    On the plus side, this design comes with built-in energy storage for the night, it can be used for agriculture, and it might be possible to increase its efficiency by placing photovoltaic cells in the collector area.

    If you consider that this thing will be a huge tourist attraction, building it will definitely be worth it.
  • ZZZ (Score:2, Interesting)

    by Organism ( 457220 )
    Reminds me of This article [zzz.com.ru] I read a while ago.
  • Better idea (Score:5, Funny)

    by glowingspleen ( 180814 ) on Monday December 10, 2001 @08:58AM (#2681583) Homepage
    It would be easier to build a machine that collects and processes the sweat of the nervous investors on this project...
  • Weather Patterns (Score:3, Interesting)

    by Detritus ( 11846 ) on Monday December 10, 2001 @09:09AM (#2681610) Homepage
    Has anyone looked at the possible effects this would have on local weather patterns?
  • Weather impact (Score:2, Interesting)

    by Nonac ( 132029 )
    The article says nothing about the possible impact this will have on rain patterns in the area.

    I've read that airliner jet streams appear to change weather patterns in the US, but jet streams seem minor compaired to 20 square kilometers worth of heat creating a permanent cloud in one location.

    Won't this draw humidity that would otherwise fall in other nearby areas?
  • I would be highly skeptical of a project like this. It has a huge initial price tag, even if EVERYTHING goes according to plan. What if it doesn't go according to plan? With it so high up, maintenance costs could be extraordinary if anything went wrong. This is a zero emissions plant, but it won't actually have lower emissions than a comparable fossil fuel powerplant until TWO AND A HALF YEARS later because of all the CO2 emissions created during construction?!?!? What would the lifetime of this project be?

    Spending a sizable fraction of a billion dollars to reduce co2 emissions by what appears to be an inconsequential amount doesn't appear to me to be a brilliant idea. Maybe it has some value as a test example, but if so, WHY does it have to be that big and cost near half a billion dollars.

    I'm not an Australian taxpayer, so I don't care if you go ahead and do it, but if I were, I would be highly skeptical...
    • I would be highly skeptical of a project like this. It has a huge initial price tag, even if EVERYTHING goes according to plan. What if it doesn't go according to plan? With it so high up, maintenance costs could be extraordinary if anything went wrong.

      Most of the really heavy maintenance stuff will be at or just above ground level. The only forseeable problem would be if there was some design flaw that would cause the whole thing to collapse, in which case it might be easier to demolish the thing and start from scratch.
      This is a zero emissions plant, but it won't actually have lower emissions than a comparable fossil fuel powerplant until TWO AND A HALF YEARS later because of all the CO2 emissions created during construction?!?!? What would the lifetime of this project be?

      Small point: Any plant one would build would require CO2 emissions as part of the construction phase. I don't know how the CO2 outlay would compare to that of a normal coal-fired plant. I would guess that the Aussie project would be slightly higher.
      Spending a sizable fraction of a billion dollars to reduce co2 emissions by what appears to be an inconsequential amount doesn't appear to me to be a brilliant idea. Maybe it has some value as a test example, but if so, WHY does it have to be that big and cost near half a billion dollars.

      "An inconsequential amount?" Compared to what? Mt. Pinatubo, perhaps, but compared to a coal plant over the same period, it's a huge savings.

      The prototype for this was already built in Spain during the '80s. It sounds like it collapsed because the builders cut corners.
      I'm not an Australian taxpayer, so I don't care if you go ahead and do it, but if I were, I would be highly skeptical...

      As would I. But all you've done is ask questions. You haven't demonstrated that this is a bad idea. It will only be a bad idea if it turns out that there aren't good answers to those questions.

      Keep an open mind. Keep asking these questions, but don't presume you already know how the answers will turn out.
  • The state of Victoria needs about 7600MW of power. The proposed convection tower's *peak* output is 200MW. For comparison, the two gas power stations I have data on (I work for an energy company here in the UK) are 600MW and 850MW. It seems like the tower is playing in the right ballpark, although it really is completely dependent on its mean output, not its peak.

    BTW, the gas power stations produce power extremely close to their capacity, 24 hours a day. Power is expensive to store, so you really try and avoid overproduction. If the tower's output varies wildly over a 24-hour period, or even seasonally, this will be a disadvantage.

    Still, it's a pretty damn cool idea - a zero emissions power station with no requirements for supply lines, *and* it's already been prototyped in Manzanares. I wonder if a *smaller* tower might be a better idea (cheaper, less of an eyesore), using the principles of micropower [wired.com] to build a robust, distributed network of smaller-scale power stations, rather than fewer, giant power stations.

    Damn, distributed network? This is sounding like the internet power grid...
  • by Anonymous Coward
    In order to make any sense at all, electricity has to be generated for less than 5 cents per kilowatt hour. (Your electric co charges 10-15 cents per kWH, and the difference is the cost of getting it to you.) At a construction cost of $670 M, the interest alone (at 10% per year, in the ballpark for a risky project like this) comes to $7,667 per hour. At 200 MW, and assuming no downtime and 100% of rated capacity (neither of which is likely), that comes to 3.8 cents per kWH, JUST FOR INTEREST ALONE! Add in any sort of operating costs, and it just doesn't look all that feasible to me.
    • Yeah, but they were also pricing a coal fired plant at $600M, so that would cost (using your numbers) $6,850 per hour in interest costs alone (3.4 cents per kwh). So, in order for the development cost to make this unfeasable, a coal fired plant would have to generate a KWH of electricty on less than 0.4 cents worth of coal. Further, you are not factoring in any dollar value for the tradeable carbon credits a wind powered plant would produce compared to a coal fired plant.


      The person quoted in the article as syaing that it wouldn't work was the guy who wanted to build lots more 1 MWH "conventional" windmills.


      For those who didn't take finance, you need to calculate the "opportunity cost" of spending moneyt on a project as if you were financing it.

  • why erect it? (Score:2, Insightful)

    by Anonymous Coward
    One of the big objections was to the eyesore of a 1 km tower. Also it would seem a lot of expense and risk is associated with such a tall tower.

    So does it have to be vertical?

    Just find a nice mountain that is snow covered year round and that lives next to a desert. (Death Valley anyone?). Build an insulated chimney from the base of the mountain to the top, following the terrain. Having it lay on the ground will make it a heck of a lot cheaper, easier to maintain, it won't fall over, and it won't be an such an eyesore.

    Also a 20km base is a lot of real estate. A green house is very good from a reliability and fuels stand point. But, could you use other heat sources? How about rotting compost or geothermal?
    This system would do well in Iceland. Plenty of hot springs and plenty of mountains
  • by Morgoth_Bauglir ( 261701 ) on Monday December 10, 2001 @10:55AM (#2681937)
    Why build a permanent tower?

    I've been thinking about this for a while-- for both power generation and city-wide air conditioning-- (though there are obvious dangers and complications.

    Use a cloth tunnel that is raised by dirigibles as the chimney. Install the generators at the base.

    The cloth chimney would presumably be cheaper-- although obviously less durable. But it would open the possiblilit for chimneys miles long.

    I've also though that a kite at the end of the chimney (buffetted by the chimney's exhaust) could suppport the entire structure.

    A light transparent, IR opaque chimney could increase the heat inside the chimney itself-- regardless of the area theat it draws from.

    What is the advantage of having the generators off the ground? As long as the air flows through does it make a difference?

    Another alternative would be ground based tunnels.

    Erect an arched greenhouse-- and make it several hundred kilometers long-- run it up the side of a mountain. Instantly, LA could have cool ocean breezes, no temperature inversions and the American West would receive more rainfall (and smog).

    But then-- what would happen to the rest of the world?
    • Nice idea, but it'd be too heavy for dirigibles to lift, I'm sure.

      Let's say the tower is 100m in diameter and the cloth weighs 25g / square metre, which is pretty optimistic, I'd say...

      that's 2*pi*50 (radius) * 1000 (height) * 0.025..

      7853 metric tons.

      A cubic meter of hydrogen will lift about 970grams at sea level.

      That's pretty heavy.

      so (ignoring the height of the tube), that's 8095876 cubic metres of hydrogen required to lift the thing.

      That would need a sphere roughly 250m in diameter to hold it up.

      Okay, so maybe that's just about possible, but that's only a very optimistic guess.... I've not counted for the fact that the dirigible is going to need to be able to lift itself, that you'd need a hydrogen/helium mix to stop it being dangerous, that the tunnel might be twice as wide, that the cloth might be heavier, and of course that the cloth would be much heavier once it has been rained on...
    • cloth isn't strong enough to handle lateral wind blowing against the tower. Cloth also lets heat escape much faster than concrete. The tower works because the top of the tower is so much cooler than the ground. The warmed air rushes up past the turbines. The airflow is fastest near the base where the base meets the tower. The generators should thus be located there. If you put a kite on top, you're slowing the air coming out of the chimney because it has a kite in the way. If a kite was there, and it got blown out of the airstream from the chimney by a lateral wind, it would be useless. Any kite or blimp would be affected by lateral winds. This would place additional stresses on the tower. Accounting for that and strengthening it would add more weight, possibly more weight than the kite or blimp would lift.

    • A cloth chimney a km high, held up by a kite powered by the exhaust? Sounds like a perpetual motion machine to me. Do you know how heavy that much cloth would be, even using the thinnest available and ignoring strength factors?

      Ignoring that we have to consider how to keep this chimney's shape in the strong winds up there, free from twists and folds...
    • Thanks for the feed back.

      Please read "cloth" as any flexible substance (plastic, aerogel, whatever).

      All of the lift would not need to come from the terminus. In fact that's probably a bad idea.

      A better idea would be modular, tubular hotair balloons connected to form an enormous chimney. In the event of catostrophe, the individual sections would be bouyant, or close to weightless, so there would be little danger from the fall-out.

      Sections could be replaced rather than replacing the entire structure. (Materials could change depending upon altitude, solar exposure,temparature).

      The kite could be a robot glider with solar-powered motor backup for recovery from lateral winds. (these already exist I think).

      I still think the tube up a mountain is the best/ lowest maintenance idea (just not as interesting).
  • South Africans are always quick to point out that not everything revolves around the Aussies.
    See for example this [saep.org] 1998 article.
  • Just replace the heat-sinks on all those overclocked Athlons with 100m PVC pipe towers, mini-turbines, and voila!

    Yes, that's a joke. Although... large server farms... hmmm... Or build it over a busy highway intersection? Is automobile exhaust hot enough to be useful? I know cities are noticably warm than the countryside around them (asphalt, mostly, but all those heated buildings do matter a bit...)
  • This reminds me of an article I read in Analog magazine years ago about building massive convection towers along the coast of the US to deflect hurricanes.

    According to the article, by messing with the relative temperature and humidity at ground level and at high altitude, you can create a pressure system that isn't conducive to hurricanes, which would tend to essentially push an incoming hurricane off to the side. Build a line of these along a hurricane-prone coast, the author said, and they'd pay for themselves within a decade just from the cost savings of not having to rebuild after a couple major storms.

    I was pretty skeptical, but what little I remember about the principles behind the idea sounds almost identical to what today's article describes, so maybe it wasn't as kooky as it sounded.

    Did anyone else read the same Analog article? Please post if you know which issue it was in -- I'd love to go reread it, since I've forgotten most of the technical details at this point.

  • The real math (Score:2, Informative)

    by Friendly ( 160067 )
    Assumptions:

    $670 million in construction costs
    no maintanence charges
    life of loan is 20 years
    life of plant is 20 years
    construction is instentanious (no time paying interest with out plant online)
    monthly interest payments at 10% (0.0083% per month
    No down time and all power used as produced

    For 200MW average power output
    Total cost incluing interest $1,770,546,502.78
    Total output over 20 years 35040000000kW
    Cost per kW $0.05

    For 100MW average power output
    Total cost incluing interest $1,770,546,502.78
    Total output over 20 years 17520000000kW
    Cost per kW $0.10

    This could turn out to be more expensive to produce the energy than traditional sources, but the pollution credits could change thet. Also some one pointed out that this would take two and a half years to get it pollution credits in the black because of what is released during construction. Well I would like to say that building any other type of power plant will produce its own share of construction related pollution.

    What I do not understand is this. By green house do they mean glass building filled with plants, or do they mean glass building filled with empty space over dirt. Plants would absorb energy (as they will be turning the sunlight into food) and less energy would be put into the air that needs to be heated. Also wouldn't it be better to build in condensors along the inside of the chimney as "dry" air weighs less (so it moves faster), has a lower latent heat energy (has a greater change in temperature with the same amount of heat), and condensing water gives off heat (the activation energy needed to vaporize water in the first place).

    Friendly
  • Here [www.sbp.de] is a link to the designers of the original plant in Spain. Under "Index - Solar Power Plants" you will find more on both the Solar Chimney and a Dish/Stirling combination.

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