Thermal Solar Plant To Be Erected In Australia

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 ."

Comments

Is this the time for renwable energy

[slashnik]

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

agricultural tie-in

[Barbarian]

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.

Re:agricultural tie-in

[cybercuzco]

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.

Re:agricultural tie-in

[markmoss]

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...

Weather Patterns

[Detritus]

Has anyone looked at the possible effects this would have on local weather patterns?

temporary tower alternative

[Morgoth_Bauglir]

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?

Re:Um... what about...

[Saeger]

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.

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