Solar tower

[lionking]

Australian company Enviromission has announced that it will begin construction of a pilot solar tower this year. The idea is to untimitely build the world's tallest construction, a tower more that a kilometer high. At the base will be a canopy, or hothouse, with a diameter of 5-7 kilometers, heating the air which will rush up the tower equipped with turbines. One of the advantages of this type of solar power generator is that it would work at night as the ground temperature would always be greater than the temperature a kilometer up. I recall reading that construction costs would approximate those of a coal fired or nuclear plant, while producing the same amount of power, but with negligible running costs and no emissions.
I'm sure there will be significant construction difficulties, but the project seems to make sense. Comments?
Link www.enviromission.com.au.

 

[EternalSceptic]

Australian company Enviromission has announced that it will begin construction of a pilot solar tower this year. The idea is to untimitely build the world's tallest construction, a tower more that a kilometer high. At the base will be a canopy, or hothouse, with a diameter of 5-7 kilometers, heating the air which will rush up the tower equipped with turbines. One of the advantages of this type of solar power generator is that it would work at night as the ground temperature would always be greater than the temperature a kilometer up. I recall reading that construction costs would approximate those of a coal fired or nuclear plant, while producing the same amount of power, but with negligible running costs and no emissions.
I'm sure there will be significant construction difficulties, but the project seems to make sense. Comments?
Link www.enviromission.com.au.

In the part of Austria where I live there are hundreds of wind power stations (at the end this is also solar energy) and they are pretty successfull. Then there is the gigantic flywheel called "moon" which drives ebb and tide and there are power stations which use this energy. Besides the construction difficulties, which can be managed IMO, I can't see anny reason why it should not work

 

[MRC_Hans]

I think the wors problem if this thing is its size. And I am not referring to construction problems, but something with a diameter of 5-6 kilometers, and a kilometer high, that is a prohibitive amount of real estate to take up or overshadow, in a lot of countries. In Denmark, the prize of the ground needed would be so high that the produced power wouldn't even pay for the mortgage.

I realize this is probably not too big a problem in Australia.....

Hans

 

[Rasmus]

I have read something about this type of generator a long time ago. I think it said that the area underneaht the structure could still be used for farming etc.

On the other hand, the wind would be rather strong. Not sure how various crops cope with that, and I think it was seen as a potential problem as the structure would at best end up moving a lot of dust around.

Either way, I am very excited to hear that someone is trying to build one at this size.


(Oh, it says here that the actual tower will be shorter, and a brief search on the website didn't show me any dimensions?)

 

[Indolent Wretch]

I have read something about this type of generator a long time ago. I think it said that the area underneaht the structure could still be used for farming etc.

Me too, I'm sure some wind resistant crop could be chosen, and the wind won't be particularly severe at any real distance from the centre.

It's a nice idea this, always liked it. It's simple, some of your generators are low down so they are easy to replace, construction is pretty simple, other than the generators there are no moving parts and the energy creation side needs no fuel transported to the plant.

The world is full of deserts with non-usable land, shed loads of baking sunshine, and they tend to be areas with a very low real estate cost.

However governments seem to be very reluctant to help pony up the cash and actually build a full scale one which is a real shame. I know Bill Gates is busy be couldn't he start getting interested in carbon neutral power generation as well as everything else? After all his operating system burns quite a few unnessecary gigajoules every year.

 

[Hindmost]

It looks feasible, but the power output is low. 200 MW is just not that much power. Building the tallest tower in the world is also not going to be cheap or easy. This is twice the height of the Taipei 101--construction of that size built to meet all the possible weather and earthquake needs should prove interesting. (I don't know if Australia is in a high earthquake zone) Putting it up in the outback would provide a resonable capacity factor due to the favorable weather...for solar power.

glenn

 

[bjornart]

A kilometer high tower is really cool, but how does such a construction compare in cost and efficiency with just covering the same area with solar cells?

I guess there might not be very good numbers on that, but a 1000 m tower has to be a very challenging build, and the two step process of heating air and running it through a turbine can't be all that efficient.

 

[lionking]

It looks feasible, but the power output is low. 200 MW is just not that much power. Building the tallest tower in the world is also not going to be cheap or easy. This is twice the height of the Taipei 101--construction of that size built to meet all the possible weather and earthquake needs should prove interesting. (I don't know if Australia is in a high earthquake zone) Putting it up in the outback would provide a resonable capacity factor due to the favorable weather...for solar power.

glenn

I'm pretty sure this is the output of the pilot plant only with the real one having much higher generation. No earthquake problems to speak of, and land and sunshine are both plentiful, so if it doesn't work here, it never will.

 

[Molinaro]

As I remember this story, it is to be built in China.

 

[Hindmost]

I'm pretty sure this is the output of the pilot plant only with the real one having much higher generation. No earthquake problems to speak of, and land and sunshine are both plentiful, so if it doesn't work here, it never will.

The 200 MW was off the link you provided. The pilot plant--off the same link--indicated it had an output of about 50kW over a period of 7 years. I think the idea is to put 5 towers in the same area to yield 1000MW...that would be equal to a small nuke facility

glenn

 

[Rasmus]

the "tower" shouldn't be too difficult to build, the structure doesn't need much force to keep it up. The structure doesn't need to carry anything, after all. (my first idea would be tons of clingfilm and a couple of ballons to drag it up ...)

I don't think it can be compared to a building where people work and live in. This is assuming that the generators will be set up low in the tower and not be placed in intervals up to the very top.

The tower wouldn't even need much insulation or anything, right?

 

[jimbob]

I'm pretty sure this is the output of the pilot plant only with the real one having much higher generation. No earthquake problems to speak of, and land and sunshine are both plentiful, so if it doesn't work here, it never will.

The fewest of any continent.

I have a great idea to stop us being dependent on the Arabs for oil:

Why don't we invest massively in building solar power stations in the world's hot deserts, like in North Africa and the Middle Eas....

Seriously, I do think it is a good idea; much as I like the idea of the technical challenges associated with nuclear fusion and the ITER, I think the best place for a fusion reactor is 150 Gm from here.

You are creating something ten times hotter than the surface of the sun, controlling it with magnetic fields from liquid helium-cooled superconductors (right next to this) and then you are going to use it to DRIVE A STEAM ENGINE??? or something else equivalent.

Don't forget the Beryllium blanket (nice one for the toxicologists).

I'd love to seee it work, I am an engineer, so like the idea of these toys, but I think this, and other forms of solar concentration are probably better (especially for hot-cloudless areas with low populations).


Jim

 

[Soapy Sam]

First I heard of the idea was an SF story at least 20 years ago. Maybe Clarke, but I don't recall for sure.
("Tales from the White Hart" maybe?)
The idea definitely appeared in New Scientist at least once as a serious project.

I think it's one of those ideas that resurface every decade, then die in the funding stage. It would be interesting to see one built. I wonder if it would act as a condenser / water supply as well? That would be a plus in Australia.

 

[fishbob]

Look at the video. If the tower is 1000 meters tall, then the apparent diameter is about 100 to 150 meters. 32 turbines at the base catch the inrushing air at the base.

I took an architecture class in the mid-70s (Univ of Tx) on building with alternate materials - taught by an odd character named Pliny Fisk. Most of the class involved actual construction of various ideas, on his property outside of town. The university wouild not allow him to do this stuff on campus due to the large piles of 'recycled materials (junk) and due to 'safety concerns' (students climbing around 30 feet in the air with hammers and nails).

We made adobe tiles, made used flourescent light tubes into solar heaters, built solar heated walls out of empty beer bottles, and built a solar tower about 35 feet high. The tower was three sided, about 8 feet across, made from sheets of tin that were painted black. The thing had a turbine across the top to measure upflowing air speed. The idea was to dig a trench about 50 yards long, cover it to make a tunnel, connect it to a residence as a fresh air source, and connect the residence to the tower as an air exhaust. Air flowing underground was supposed to be cooled, and reduce the need for air conditioning. This was an ongoing project, and I never found out what the results were, however, I could feel a good breeze inside the tower on a hot Texas day.

Properly engineered, I can see this idea working. The economics will be the difficult part.

 

[lionking]

The 200 MW was off the link you provided. The pilot plant--off the same link--indicated it had an output of about 50kW over a period of 7 years. I think the idea is to put 5 towers in the same area to yield 1000MW...that would be equal to a small nuke facility

glenn

Thanks, my mistake.

 

[Rasmus]

A kilometer high tower is really cool, but how does such a construction compare in cost and efficiency with just covering the same area with solar cells?

As far as I nkow, solar cells still have a negative energy output, i.e. you put more energy into the production than you will ever receive during the lifetime of the cell.

Hence, plastering the desert in solar cells will buy you a massive net loss in energy.

 

[Rasmus]

TI think the idea is to put 5 towers in the same area to yield 1000MW

The higher the tower the better.

I would like to see the tradeoff between ground area covered and tower hight. I suspect there's a reason they intend to have the tower so high rather than just cover an even bigger patch of desert.

 

[Modified]

Could one of these things be built up the side of a mountain? It would obviously be less efficient, but a lot easier to build.

 

[lionking]

Could one of these things be built up the side of a mountain? It would obviously be less efficient, but a lot easier to build.

The only problem would be that the hothouse would be in the shade of the mountain for part of the day, and besides, there would not be too many suitable mountains in the desert.

 

[Hindmost]

Could one of these things be built up the side of a mountain? It would obviously be less efficient, but a lot easier to build.

The mountain might affect the operation significantly that it would not be practical. Less solar input and possible unfavorable air currents and temperature inversions--but I am just speculating.

It will be interesting to see if or how this progresses. Since the pilot plant operated back in the 80s, there obviously hasn't been any rush to scale up. Energy prices may be making it cost effective.

glenn