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Power Earth Technology

Massive Solar Tower Planned For Arizona 407

Posted by Soulskill
from the i-can-see-my-house-from-here dept.
inkscapee writes "It's simple, clean, low-maintenance, and cost-effective: using hot air on a large scale to generate electricity. No, this not a plan to use Congress to generate power, though that would certainly be an endless supply — EnviroMission will use air rising up a tall tower to generate 200 megawatts of electricity. The concept is simple: a giant greenhouse at the base of the tower warms the air. The warmed air rises through the tower and turns turbines, which generate electricity. The taller the tower, the faster the air moves, which increases power output. This structure will be a monster at over 2600 feet tall. It works in all weather, and if there is a feasible water source, food could be grown in the greenhouse."
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Massive Solar Tower Planned For Arizona

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  • by Anonymous Coward on Monday July 25, 2011 @02:33PM (#36873818)

    But too bad - the greenhouse effect is a myth, as we all know.

    • by ByOhTek (1181381) on Monday July 25, 2011 @02:48PM (#36874008) Journal

      That's not the only myth they are tackling

      Put this tower in a hot desert area, where the daytime surface temperature sits at around 40 degrees Celsius (104 F), and add in the greenhouse effect and you've got a temperature under your collector somewhere around 80-90 degrees (176-194 F).

      It emits absolutely no pollution - the only emission is warm air at the top of the tower. In fact, because you're creating a greenhouse underneath, it actually turns out to be remarkably good for growing vegetation under there.

      Hmmm... What plants grow at those temperature?

      Maybe in cooler climes it can be used to grow stuff colder climes (or seasons), however at the locations where it'll be warmer and have more stable temperatures, it's gonna get awful damn windy... That means, amongst other things, rugged plants, lots of soil loss (going straight into the turbines or filters that will need to be replaced!) , and lot of moisture loss.

      It's looks like an interesting concept for an energy source, but as for green growing space... doubt it.

      • by ColdWetDog (752185) on Monday July 25, 2011 @02:52PM (#36874046) Homepage
        You grow plants at the periphery of the collector where it's warm, not hot and less windy. At least, that is the plan. Nearer to the turbines will serve as a training ground for Arrakis.
      • by vlm (69642)

        lots of soil loss

        Where's that soil end up? On the greenhouse glass, of course. If the wind flow is enough to toss heavy rocks 2500 feet up (size and weight of hailstones?) then they'll make quite a dent when they hit the glass below.

      • Re: (Score:3, Insightful)

        by vlm (69642)

        Hmmm... What plants grow at those temperature?

        Locally mix in some cold air during the winter, it'll be nice.

        Kind of like asking, if my natural gas furnace burns a 2500 degree blue flame, how can I use it to keep my house at 72 degrees in the winter?

      • Yes, whoever thinks you need a greenhouse to grow plants in the Arizona desert obviously has never been there.
        • by Dare nMc (468959) on Monday July 25, 2011 @04:53PM (#36875596)

          I am guessing you have never spent the night outside in the Desert.
          I live in the AZ desert, and have a green house for 3 reasons. 1) the birds, rabbits, etc even eat the hot pepper plant northern rabbits wont touch. 2) Cold nights, day to night swings of 30F are the norm, northern plants seam confused by this, and don't grow (but don't die either.) 3) Humidity, normal plants lose way too much humidity without a enclosure. My roof panels auto open at 90 degrees, and the misters turn on at 95 then close up to maintain overnight.
          #1 seams to apply here, #2, probably be good dual purpose for Nov to March.#3 the moisture should settle out on the way up as it gets cooled. Thus if captured would be available. However I would guess the cooling affect of the water down low, would reduce the efficiency, and thus not be desired.

      • by Dunbal (464142) * on Monday July 25, 2011 @03:31PM (#36874580)

        It's the typical "we want a federal grant" spiel. It will cut your grass for you and cure cancer, as well as produce cheap reliable clean energy. Of course there's no logistical problems involved in keeping plants at the optimal temperature, watering them, etc. Nah, some dufus in a lab coat who has never seen a vegetable outside a supermarket said "hey, we could probably grow plants there too".

        Of course it would make a hell of a gnomon for a giant desert sundial. That would keep future archaeologists guessing for quite a while. Just to fuck everyone up they should align the doors with compass directions.

    • So you are saying the tower is constructed only by increasing carbon dioxide in an open chamber?

      Odd, I thought it used heat trapped by passing through glass.

  • by Baloroth (2370816) on Monday July 25, 2011 @02:39PM (#36873886)

    The mammoth 800-plus meter (2625 ft) tall tower will instantly become one of the world's tallest buildings.

    Compensating for something there, Arizona?

    • by jhoegl (638955)
      Well, we felt that the Washington Monument wasnt big enough to express how hot women are in Arizona.
    • Don't be ridiculous.

      It's an Australian based company erecting this thing.

    • by MiniMike (234881)

      The mammoth 800-plus meter (2625 ft) tall tower will instantly become one of the world's tallest buildings.

      Compensating for something there, Arizona?

      No, they're just really excited about clean energy.

  • Decent idea. (Score:2, Informative)

    This is, by far, the kind of tech we need to be investing in, preferably starting a decade ago. Genuine renewable, reliable power - are deserts hot? Yes? Let's make power from it! It'll be terribly uneconomical at first, of course, but it can improve given time. And it's worth trying out. It might not pan out, but it's sure as hell a better investment then 1.1 million in legal fees trying to surpress video games or whatever other legal action is popular at the moment.

    So even if it's silly, go for it, Ariz
    • Re:Decent idea. (Score:5, Insightful)

      by ColdWetDog (752185) on Monday July 25, 2011 @02:43PM (#36873936) Homepage
      Seems like a reasonable idea. The wikipedia article [wikipedia.org] has more info than the TFA. There have been a couple of much smaller systems build world wide but little info on how well they work or stand up. I'm a little concerned about the 'limited maintenance' claim. It's a big structure in a hostile environment and has lots of moving parts. One wonders just how optimistic their financial spreadsheets are and how far they will diverge from reality.
      • Re:Decent idea. (Score:5, Informative)

        by AdmiralXyz (1378985) on Monday July 25, 2011 @02:56PM (#36874104)

        lots of moving parts

        Maybe in absolute terms, but virtually any other means of electrical power generation has more. The only moving parts here are the turbines. Not only do we have plenty of experience with running turbines (since every other power source uses them), but they should all be independent from one another, so a failure of one doesn't lead to damage or require a shutdown, it just means you're putting out a little less power.

        • by wagnerrp (1305589)
          The problem is that those turbines are a couple thousand feet up over top a giant inverted funnel.
          • by wagnerrp (1305589)
            Scratch that. I thought they were installing them inside the tower, not in a ring around its base.
          • by nschubach (922175)

            I was under the impression that the turbines surrounded the base of the tower at ground level. Every diagram of systems like this show the same layout.

      • by Baloroth (2370816)

        This was my thought too. An 800m tower is a pretty big target for winds, but I'm pretty sure Arizona isn't all that hostile an environment, though, when I think about it. Very few/ no storms (dustorms maybe), I don't think it gets earthquakes, next to no rain. And the only moving parts, as far as I understand it, are the turbines, which isn't really "a lot". Any power plant is going to have maintenance costs of some kind. This needs no fuel, and supposedly can work at night. It doesn't use rare, expensive,

        • Re: (Score:3, Insightful)

          by Anonymous Coward

          I'm kind of annoyed when people say "empty desert." The problem with this is a desert isn't empty and the animals that do live there need more area to hunt out edible plants and other creatures than more rain prone climates.

          Don't get the idea that I'm some cactus hugger, it's just I live in the arizona desert and people think it's all sand when there is quiet an abundant variety of life that can only be found in an area that's already relatively small.

          • Fair enough, though I'm sure quite a few animals lived on the area of open pit mining too. The upside here is that there is far less environmental disruption for this than other power sources.
      • The big problem is the 0.5% efficiency quoted by Wikipedia. Not only does this waste a lot of nice desert land, but it make the economics difficult. I'd rather see 20% efficient concentrated solar with molten salt storage. Less land and, I'll bet, cheaper in the long run.

    • by mlts (1038732) *

      Agreed. It has moving parts (turbines), and needs some architecture on a vast scale, but if done right, we (meaning scientists) may learn some technological abilities from this to make it useful in other areas.

      I wonder how this compares by price compared to just taking the same amount of area and laying down photovoltac cells either actively tracking the sun, or just passively facing south. Passive tracking gets less sunlight, but doesn't require the presence of moving parts.

    • I like this tech too, really look like it has solid potential!

      This was in the works since 2001 so a decade seems about right. [enviromission.com.au]

    • Re:Decent idea. (Score:5, Insightful)

      by cmiller173 (641510) on Monday July 25, 2011 @03:29PM (#36874536)
      Curious what the effect of launching a stream of hot air a half mile up will have on local weather patterns. Would suck big time if this upwelling of hot air caused a localized artificial high pressure zone that shifted the natural weather patterns. Just say'n
  • into cooler air, higher up. I wonder what the weather will be like near that tower after it goes into operation? This could be a neat experiment!

  • At "176-194 F", I'm not familiar with any plants that grow well.

    The efficiency of a heat engine depends on the difference between input and output temperatures, so this can't be very efficient, though efficiency is less important when the input is so cheap.

    • Yellowstone has some bacteria that grow at those temperatures, perhaps they could be molded into colorful bacon strips.

    • by vlm (69642)

      At "176-194 F", I'm not familiar with any plants that grow well.

      The sad part is that is well done for beef. I prefer medium well, myself, around 155 F.

      Perhaps on a cloudy day you could stampede cattle under the greenhouse, and have a rather large steak dinner a couple hours later.

  • No, this not (sic) a plan to use Congress to generate power, though that would certainly be an endless supply

    Yep, another old, tired, stupid and vacuous panning in the summary that you'd expect from a 14 year old who thinks he's massively clever. This is is what Slashdot has become.

  • by molo (94384) on Monday July 25, 2011 @02:53PM (#36874058) Journal

    This is a ridiculous idea. The only structure that is taller than 2600 ft is the Burj Khalifa (Burj Dubai), which is 2717 ft.

    http://en.wikipedia.org/wiki/List_of_tallest_structures_in_the_world [wikipedia.org]

    The idea that we would build the 2nd tallest structure in the world for 200 MW is ridiculous. This doesn't even come CLOSE to being a top producer of energy per power plant. The top 10 power plants in the world all produce more than 6000 MW. Even the largest biofuel, geothermal and tidal plants currently exceed 200MW.

    http://en.wikipedia.org/wiki/List_of_largest_power_stations_in_the_world [wikipedia.org]

    -molo

    • by GameboyRMH (1153867) <gameboyrmh@NoSpAM.gmail.com> on Monday July 25, 2011 @03:05PM (#36874238) Journal

      Taller doesn't necessarily mean more expensive. It's a big metal tube, not the same as a full building. It doesn't even need to be habitable. Structures of similar heights have been built for radio transmission you know.

      • by molo (94384)

        Who said anything about more expensive? As for "similar heights", the largest radio tower was the Warsaw Radio Mast [wikipedia.org], which was 2164 ft before it collapsed. The currently tallest radio mast is the KVLY-TV mast [wikipedia.org] which is 2063 ft. This would be 26% taller than KVLY, would be free-standing (unguyed), and would be solid (wind cannot blow through it). This tower is more comparable to a occupied structure.

        The current highest capacity wind turbines are 7.6 MW. I haven't been able to find figures on the area pro

    • Nobody is living inside the tower.

      It will be significantly easier to build this than any building for occupation at half that size.

    • by pla (258480) on Monday July 25, 2011 @03:12PM (#36874312) Journal
      This is a ridiculous idea. The only structure that is taller than 2600 ft is the Burj Khalifa (Burj Dubai), which is 2717 ft.

      The complexity of a giant hollow tube doesn't really compare well to an office and apartment building designed to safely hold tens of thousands of humans at a time.

      As for the cost, the average US nuclear power plant puts out very close to one gigawatt, and costs on the order of 6-9 billion dollars to build and another 30 billion in expenses over its lifetime. This tower has an estimated construction cost of 750 million dollars, and although I can't find any estimates of the maintenance cost, I'm going to go out on a limb here and say "a hell of a lot less than completely rebuilding it every 3 years of its spec'd lifetime".

      Sounds like at the very least a better-than-breakeven proposition vs nuclear, IMO - With no waste or risk of disaster.
      • by Solandri (704621)

        As for the cost, the average US nuclear power plant puts out very close to one gigawatt, and costs on the order of 6-9 billion dollars to build and another 30 billion in expenses over its lifetime. This tower has an estimated construction cost of 750 million dollars, and although I can't find any estimates of the maintenance cost, I'm going to go out on a limb here and say "a hell of a lot less than completely rebuilding it every 3 years of its spec'd lifetime".

        Average nuclear reactor output in the U.S. is

    • by Megahard (1053072)
      Agreed. You could get the same amount of power from about 30 standard wind turbines [wikipedia.org].
      • by w_dragon (1802458)
        Maybe you haven't been to many deserts, but lots of wind isn't generally a defining feature.
    • It's not habitable. With a payback period of 11 years, it's doing pretty well, particularly for a renewable energy plant.

  • Anybody with knowledge on the topic: is there a way to add a Thermocouple element to this to increase the potential for power generation? Or is that an insanely expensive proposition or just a flat out bad idea?
    • This *is* a giant thermocouple.
      Aside from being stupidly expensive, anything you took out via thermocouple at the base wouldn't come out as power through the top.
      Moreover, the heat differential wouldn't be nearly the same.
      In essence, you'd be spending much much more money to make much less power.
      • Waste heat. You have a turbine at the top, you have a thermocouple near that that the exhaust runs through, QED. By cooling the exhaust, the thermocouple creates a vacuum, but also weighty air that needs to be pushed; of course it doesn't need to be pushed as far. Totally doable.
    • by nschubach (922175)

      What would the thermocouple be doing? Facilitating the opening/closing of vents?

    • by rubycodez (864176)
      the efficiency of a thermocouple is very low, under 7%. A heat engine will produce many times the power of a thermocouple in the same situation.
  • Would this work in the heat islands created by cities?
  • Rain, etc. (Score:3, Interesting)

    by MSesow (1256108) on Monday July 25, 2011 @03:09PM (#36874278)
    I know this is in a desert, but it will rain on rare occasions; what will they do with the water that falls on the structure? I imagine it would not be worth while to collect it and transport it somewhere, since it will be so rare. I feel like they probably have considered this, and I just want to know what decision they came to. Put it all in a big gutter, feed it into a huge sump (or a lot of little ones), or what? Also, what about dust buildup - will it get cleared by wind (like the Mars rovers' solar panels) or will someone have to go up there with a giant squeegee to clean it off every now and then? Again, I bet they have thought of it, and I am curious about what ideas they came up with. Maybe they only clean it when it rains? Maybe every time they do clean it, it rains the next day? Who knows?
    • Well the tower being dirty shouldn't cause any problems, the greenhouse roof being dirty would reduce efficiency, I don't know if it's self-cleaning. Rain would be no problem at all, when the desert sun comes up the water will disappear reeaall fast...

  • In 2005 EnviroMission said that the first solar tower would be up and running before year 2008 in Australia. That never happened.

    Now in 2011 they say that it will be ready at the start of 2015 in Arizona. I hope they succeed this time.

  • to generate electricity, but isn't a major hurtle for projects like this one the distance from where the electricity will be consumed? They're confining this to the desert, because of the daytime temps, but most power is being used on either coast, thousands of miles away.

  • by NoKaOi (1415755)
    To put things in perspective...this thing costs less than a single B-2 bomber, and about the same as a few 747s or a large cruise ship. Which is more beneficial?
    • on whether or not there are any contractors for these planes in your district.
    • by ErikZ (55491) *

      Depend if you need a B-2 bomber, a few 747s, a large cruise ship, or a power plant.

    • by AP31R0N (723649)

      How beneficial is a large cruise ship in delivering ordinance deep in enemy territory through air defense networks?

      The money spent on a B-2 doesn't evaporate into the ether. It becomes paychecks, purchases of materials (from alloys to paper clips), stock dividends for retirement funds and so on. Those paychecks pay mortgages, rent, car payments, groceries, trips to Disney World, condoms, computers....

  • Serious Question... (Score:5, Interesting)

    by twistedsymphony (956982) on Monday July 25, 2011 @04:20PM (#36875212) Homepage
    Is there a form of viable power production that doesn't require a mechanical generator of some sort?

    I get it... turbine generators have really good efficiency and we've refined their use for over a century. But it seems to me that every worth-while method of power production uses them...
    • Wind - air turns a blade which turns a generator to create electricity
    • Hydo - water turn a turbine which turns a generator to create electricity
    • Petrol - fuel runs through a combustion engine which turns a generator to create electricity
    • Coal - coal burns and heats up water to create steam which turns a turbine which turns a generator to create electricity
    • Nuclear - a nuclear reaction heats up water to create steam which turns a turbine which turns a generator to create electricity
    • Geo-Thermal - the earth's core heats up water to create steam which turns a turbine which turns a generator to create electricity
    • Solar Tower- a greenhouse is used to heat up air which turns a turbine which turns a generator to create electricity

    Solar Cells, and Lightning Rods seem to be the only methods I can think of that produce electricity without the use a turbine/generator combo but neither are viable for wide spread use. It seems to me that we'd do well to invest in methods of converting heat directly into electricity (giant Peltiers?) without the use of a turbine/generator. I would think doing so would theoretically make a number of our existing methods that much more efficient and perhaps open the door for other methods of power production.

    • Is there a form of viable power production that doesn't require a mechanical generator of some sort?

      Radioisotope thermoelectric generator [wikipedia.org]

    • by stevelinton (4044)

      There are magnetohydrodynamic approaches. You make a lot of hot plasma, cool it by allowing to expand in one direction and then use a big magnet to separate the positive ions and negative electons, which impact different electrodes. I don't think it's terribly efficient (to put it mildly) and the wear on the electrodes is something chronic, but if you want a LOT of power (GW) for short periods (seconds to minutes) for some reason it might be usable. I think Jerry Pournells has a laser launcher powered tha

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