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Re: Really large scale solar becoming available

Unread postPosted: Mon 14 Aug 2006, 01:52:38
by oilfreeandhappy
eric_b wrote:This was discussed over a year ago. It's an unproven concept at this point, and there are many reasons to think it may never be viable. I'm not going to enumerate them again, do a search on it.

Likely just a cute investor boondoggle.


I don't think so. The previous installation was a much smaller unit in Spain. I would bet that the Engineering of the Australian project is sound, and it delivers the Specified energy. I'm anxious to see what transpires with this system.

I think the only down-sides are the same downsides as most solar and wind projects:
1. Intermittent energy which requires some type of power storage.
2. A large footprint of land is required, usually in rural areas (in this case the Outback), which requires transportation mechanisms for the employees.
3. System Maintenance could be man-power intensive.

Re: Really large scale solar becoming available

Unread postPosted: Mon 14 Aug 2006, 10:31:28
by WisJim
The big drawback is power transmission from a remote location to population centers where it is used.

Re: Really large scale solar becoming available

Unread postPosted: Mon 14 Aug 2006, 10:57:41
by Doly
WisJim wrote:The big drawback is power transmission from a remote location to population centers where it is used.


If the location isn't too remote, that's a problem that's already been solved. Many power stations are not especially near population centres.

Re: Really large scale solar becoming available

Unread postPosted: Mon 14 Aug 2006, 17:16:13
by Heusdens
oilfreeandhappy wrote:
I think the only down-sides are the same downsides as most solar and wind projects:
1. Intermittent energy which requires some type of power storage.
2. A large footprint of land is required, usually in rural areas (in this case the Outback), which requires transportation mechanisms for the employees.
3. System Maintenance could be man-power intensive.


1.
I have read about this type of solar plant that the ideal thing about it that heat can be stored under the collector (using some kind of material underneath the collector) which then is re-emitted at night, so they guarantee that it produces electricity 24 hours a day.
Of course, the power output is not constant, but will steadily rise during daytime, and drop down at night.

I have a website somewhere which explains it better, but can't find it at the moment, so will edit this later and put that in.

2.
The large surface area under the collector is some demirit, but I think it might actually be used for a usefull purpose (agricultural or something).

3.
Depends. It needs to be tested of course how the collector (a plastic material) would withstand wind and rainfall. There obviously would be some repairs.

To me the concept itself seems plausible to me, although I think they scaled it up too quick to a large sized plant. They had better tried some smaller sized one first, and have it operation for some time to test the concept, see where the concept needs adjustments, etc.

Also, it would seem that the determining factor for it's operation comes from the difference in temperature below the collector and the temperature of surrounding air at the top of the tower.
The height is needed because of the lower temperatures.

I wonder if concrete structure would be needed that high, and not some leight weight structure could also work. The structure does not need to support something, it needs only to thermaly isolate the flow of air upwards; perhaps creating a vortex flow of air would be benificial too, cause this - at least when there's no wind - would extend the chimney above the structure.

I assume that the same kind of plant would also work in colder climatic zones, and could also be used as a normal greenhouse to grow plants or vegetables, profiting from the higher temperatures beneath the collector.

Again, I think the idea is good, it has been tested in Mazaneres in Spain a decade or so ago. But the scale on which this projects goes, before further rigid testing of the concept for a longer period of time seems to me to call for problems.

Perhaps that's why they haven't already built it, and why they downscaled the height of the tower from 1 km to something like 400 m.

Environmission website

Solar mission technology

Location of Solar tower (wentworthshire, NSW, Australia)

Solar mission FAQ

Re: Really large scale solar becoming available

Unread postPosted: Mon 14 Aug 2006, 18:24:16
by Lighthouse
WisJim wrote:The big drawback is power transmission from a remote location to population centers where it is used.


The site in NSW they have chosen is close to the Australian national power grid. I drove by and had a look when I did my west to east-coast ride on my motorbike 2 years ago. Nothing there, not even a proper road. The land is not used for anything because it's hot, dry and full of red sand. At this stage they had just an option to the land. As far as I know they still have not purchased the land. But I could be wrong.

However I think it's a brave brave idea. There are a lot of stable remote deserts close to the power grid here in Australia. Lets see if they can pull it off. Don't forget the project is already 5 years in the grapevine and was scaled down massively.

Re: Really large scale solar becoming available

Unread postPosted: Mon 14 Aug 2006, 20:41:11
by Omnitir
The downsizing of the tower size is for two reasons; to meet the requirements for the governments LETDF grant on establishing no emission proof of technologies, and because improvements in the technology now make a smaller tower economically feasible.

I commented in more detail about this on my blog:
http://omnitir.blogspot.com/2006/07/enviromission-solar-tower.html

Of course most people would argue that a 50MW station is not "really large scale", but then this is only for demonstration purposes. Also of note is the reduced footprint of the smaller tower possibly making a large number of decentralised towers feasible for many areas around the world.

I imagine that in another 10 years this technology should finally become available in the wide scale commercial sense. Of course around the same time we can also expect that the advances in nanotech will lead to hyper-efficient PV cells capable of meeting the vast majority of our energy needs, so unfortunately, solar towers could very possibly become obsolete before they are adopted wide scale.

Re: Really large scale solar becoming available

Unread postPosted: Mon 14 Aug 2006, 22:16:00
by WisJim
Doly wrote:
WisJim wrote:The big drawback is power transmission from a remote location to population centers where it is used.


If the location isn't too remote, that's a problem that's already been solved. Many power stations are not especially near population centres.


The current grid in much of the USA, at least, is overloaded. There are some major windfarms in western Minnesota and the Dakotas that are producing more electricity than can be used because of inadequate grid to get power to where it is needed, Minneapolis/St Paul and other municipal centers. This seems to be a big concern of engineers working for major power companies.
And this is why I think that PVs on your roof make a lot of sense.

Re: Really large scale solar becoming available

Unread postPosted: Fri 25 Aug 2006, 11:10:39
by kokoda
Its footprint isn't that large.

The solar tower itself occupies the same area as a large sports stadium. The heat is generated by a large greenhouse which covers several square miles ... but there is the potential to use this greenhouse as ... well a greenhouse.

The illustrations clearly show that land inside the greenhouse is being used for agricultural purposes.

This could fit in nicely with some of the grimmer scenarios of a post peak oil world where people may have to gather around a centralised energy/food growing source.

I certainly hope it works out ... I am a shareholder in the company building it.

http://www.enviromission.com.au/

Nice video here

http://www.enviromission.com.au/project/video/video.htm

Re: Really large scale solar becoming available

Unread postPosted: Fri 25 Aug 2006, 14:24:38
by napoleon
Further, he says they "essentially produce energy for free."


Bullshit, if there's turbines involved, there's a maintenance cost. Think of changing a turbine that far up?

Also, I would be interested in seeing tyhe structural behind one of these babies; wind in the desert is strong enough and such a structure would make an excellent sail.

Re: Really large scale solar becoming available

Unread postPosted: Sat 26 Aug 2006, 01:16:45
by kokoda
The turbines are at the base of the structure. The tower itself is just a very long tube.

The turbines look to be easily accessable.

Solar Tower

Unread postPosted: Mon 03 Dec 2007, 12:05:44
by paimei01
http://en.wikipedia.org/wiki/Solar_updraft_tower
Image
Image
It's a big tower surrounded by glass. The air under the glass gets heated by the sun and goes up trough the tower spinning the generators
This technology is very simple, almost perfect I say, one such tower could work for hundreds of years if maintained

Australia plans to build one with a collection area of 7km in diameter.
Spain built one with an area of 244 m diameter, it worked for 8 years and generated some 50kW at it's maximum, until it was closed due to "structural problems"

I would like to see these towers wherever there is room for them, their simplicity is inspiring

Re: Solar Tower

Unread postPosted: Mon 03 Dec 2007, 16:34:07
by davep
paimei01 wrote:It's a big tower surrounded by glass. The air under the glass gets heated by the sun and goes up trough the tower spinning the generators
This technology is very simple, almost perfect I say, one such tower could work for hundreds of years if maintained

Australia plans to build one with a collection area of 7km in diameter.
Spain built one with an area of 244 m diameter, it worked for 8 years and generated some 50kW at it's maximum, until it was closed due to "structural problems"

I would like to see these towers wherever there is room for them, their simplicity is inspiring


They're simple, but 50kW for a 7km diameter construction? That's horrible. I think they're something like 2% efficient. Lack of efficiency in itself isn't bad, it's the cost and scale of the thing.

Proper solar power towers are another thing entirely. Solar Tres is 15MW, 300 times more power (Ok, it's not finished yet, but it's based on two working smaller models). Total cost 196.000.000 €. The solar tower would have to cost 650k Euros or less to equal that cost/watt. It would appear difficult for such a large structure.

I do like the simplicity of it though.

Re: Solar Tower

Unread postPosted: Mon 03 Dec 2007, 16:41:05
by davep
Oops, I see that the 50k figure was for a smaller tower. Apparently a 7km diameter one could manage 200MW, which seems a different proposition. To me, the only issue is the size of the bugger.

Re: Solar Tower

Unread postPosted: Mon 03 Dec 2007, 16:42:34
by paimei01
50 Kw is from the 244m diameter one from Spain. The size does not matter I am sure it could be built, I wonder if those towers could work more to the North, if there is enough sunshine. The area around them could be used to grow vegetables maybe ?

Golem I do not understand your post :) Yes I think CIA made those Arabs attend that flight school, they got on the planes but they weren't the ones flying the planes. I better post in the 9/11 thread

Re: Solar Tower

Unread postPosted: Mon 03 Dec 2007, 18:55:20
by Plantagenet
paimei01 wrote:Spain built one with an area of 244 m diameter, it worked for 8 years and generated some 50kW at it's maximum, until it was closed due to "structural problems"



Really great idea, but don't you mean 50 mW (MegaWatts) instead of kW?

Re: Solar Tower

Unread postPosted: Mon 03 Dec 2007, 18:59:13
by gnm
Personally I think its just a scam by some Aussie venture capitalists looking for suckers to invest. Nothing has been built. They've been floating that idea for years....

-G

Re: Solar Tower

Unread postPosted: Mon 03 Dec 2007, 19:39:13
by Tanada
Deja Vu all over again, someone needs to learn how to use the search function. Mods could you merge this thread with one of the following?

http://www.peakoil.com/fortopic17679.html+tower

http://www.peakoil.com/fortopic17561.html

http://www.peakoil.com/fortopic1278.html+tower

I suggest the latter, it is the oldest one I could find on this project, starting in Aug 24, 2004 !!!

Solar Towers

Unread postPosted: Thu 13 Dec 2007, 12:58:02
by xrotaryguy
I thought that these videos were interesting. Evidently the cost of a solar tower can be competitive, but what about the materials required to build one. The towers depicted in the 2nd video seem pretty extreme. One interesting side affect of the tower in the first video is that it actually helps to support plant life. I wonder if the area under the plastic could be used agriculturally.

http://www.youtube.com/watch?v=C-EvV90MeDY

http://www.youtube.com/watch?v=cLIiGTZxH5s

Re: Solar Towers

Unread postPosted: Thu 13 Dec 2007, 15:20:13
by steam_cannon
Wow! Cool new technology!

I've seen solar towers that concentrate light to produce steam, but this looks much simpler.

Pros
* It produces power both day and night.
* The million dollar test model has proven to be profitable.
* The design creates what could be a large greenhouse that would pay for itself and protect crops from birds and insects.
* Though condensation, it waters soil under the plastic. This could make it possible to grow crops in a very dry climate.
* With some modification it could be used to direct and store rainwater or condensation.

Cons
* It uses huge amounts of plastic sheeting. But hey, plastic sheeting is probably going to be around and available for a while. Now if we wanted to cover the plain states with these things, that's another story.
* It's better suited for warmer climates. I think it's pretty clear it would not do well with significant snowfall on it.
* Bad weather such as hail, severe winds or tornadoes would destroy such an installation.

Re: Solar Towers

Unread postPosted: Sat 22 Dec 2007, 00:57:50
by kokoda