# A Simple enough idea to this layman.  Anyone else hear about this?



## Fsappo (Jul 28, 2011)

http://www.linkedin.com/news?viewAr...hash=AULT&goback;=.gde_700507_member_63703872

Sun makes the air hot, air goes up, spins a turbine on the way, makes electricity.  First I saw about this.  Anyone else hear of it and maybe have an opposing view?


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## soupy1957 (Jul 28, 2011)

Looks do-able..........who's absorbing the start up and maintenance costs?

-Soupy1957


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## Fsappo (Jul 28, 2011)

I didnt notice, but considering they have a 30 contract to sell the eletricity and an 11 year payback and a projected 80 year almost maintanence free life it would seem private investors would be easy.


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## mbcijim (Jul 28, 2011)

There's been a group fighting these type things because of some endangered species turtle that's been quite successful.


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## begreen (Jul 28, 2011)

I've got to head out, but if you research a little you will see that there was a successful pilot program in Spain with this design. There was supposed to be a mega one constructed in Australia, but I have not seen progress there. On a side note, my son and I made a miniature one of these for a science project several years back.


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## Jags (Jul 28, 2011)

Looks pretty darn interesting to me.  Either I missed it or it wasn't included in the article, but I wonder what the total foot print per tower is.  Could we take 100 acres and drop 10 of these suckers on it??  Dunno, just asking questions.


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## Delta-T (Jul 28, 2011)

the one in Australia is in a holding patern for the time being, and they are talking "really big"...hundreds of acres, thousands of feet tall. Having trouble raising the $200 billion or so needed to build it.


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## fishingpol (Jul 28, 2011)

It looks like it belongs on another planet or a space docking station.  Almost like something you would see on a Popular Mechanics cover.  I'll wait for the homeowner rooftop model if I can get it under 20 feet tall.

You want to talk about a renewable energy source, well, here it is.


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## begreen (Jul 28, 2011)

IIRC it was on Popular Science's cover at one time.


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## oldspark (Jul 29, 2011)

Wow 200 meg, hard to believe it will generate enough wind to drive a gen that big, little maintenance where have I heard that before.


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## begreen (Jul 29, 2011)

I had a chance to watch the video now. This is the Australian project refined and move to the states for better incentives. Sparky, this is a pretty simple setup. Maintenance should be a bit simpler than a hydropower setup. 

http://www.enviromission.com.au/EVM/content/home.html

more info:
http://en.wikipedia.org/wiki/Solar_updraft_tower

prototype design:
http://www.1000friendsofflorida.org/Solar/The_Solar_Updraft.pdf


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## fishingpol (Jul 29, 2011)

Four more years until up and running and using conventional construction methods.  I imagine the will have to build a concrete plant on-site for this project.  There was mention of possibly growing plants under the collector.  I'd be curious how they would obtain water for them.  It is a fascinating project, just plain old clean energy.  Keep an eye on the plastic company stocks when they ramp up production for the collector film.  I want in...


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## btuser (Jul 29, 2011)

I like the collector idea on the bottom.  80 years is pretty cool, but there's a pretty good chance it won't be needed past that point.  11 years maybe but I can't see it being a viable energy source in the year 2095.


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## woodgeek (Jul 29, 2011)

It's a nice 'cover of popular science' concept, but I have a lot of skepticism.  In the end it is a large collector/storage system of low grade heat.  That heat can be turned to useful work at rather low thermodynamic efficiency--and the 'engine' chosen uses a design element the size of the Burq Dubai....sounds cost effective!  Its claim to fame is one moving part and a projected 80 year maintenance free lifetime. Yeeah.

Why not roof over a chunk of desert (same gain geological heat storage as this idea). extract the heat with a circulating fluid (much more effective/predictable than dusty ambient air), and convert to work with a reverse refrigeration cycle (like the old OTEC schemes) that is more efficient than the mega-tower turbine?  

Oh yeah, cuz a higher temp collector storage system has: 
--lower costs by virtue of much higher thermo eff
--a much smaller and thus lower loss storage tank
--a conventional steam turbine
--a turbine that makes money at other times using natgas

IOW, a highly optimized system that looks like the CSP systems being rolled out over the last few years!

Sadly, the cost of thermal storage in a CSP system roughly doubles the cost per kWh, and moves the power off peak (in AC climates) so is a no go economically. Moreover, the conventional wisdom is that solar conc thermal power is more exp than PV on a real-time kWh basis--several CSP projects that were funded have recently switched to a PV architecture during the planning stage.

This thing is boondoggle--I would like it better if they had made the tower prettier, and added an observation deck.


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## Fsappo (Jul 29, 2011)

Because we'll all be dead?


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## Delta-T (Jul 29, 2011)

Franks said:
			
		

> Because we'll all be dead?


no, because by then we'll actually have dylithium crystals and "turbines" of all kinds will be relegated to museums and "in the olden days" stories. Like a hand pump well, cute, quaint, and all but gone.


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## Adios Pantalones (Jul 29, 2011)

woodgeek said:
			
		

> It's a nice 'cover of popular science' concept, but I have a lot of skepticism.



In the sciences we refer to this as "Power Point Engineering"


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## jimbom (Jul 29, 2011)

Adios Pantalones said:
			
		

> woodgeek said:
> 
> 
> 
> ...


 :lol: 

That is great.  This project looks designed to produce revenue from government grants.  When government grants run out, the company may also.


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## begreen (Jul 29, 2011)

The solar updraft technology can and does work as was proven by the pilot project in Manzanares, Spain. There is a new system that has come online in Mongolia in 2010. Large scale systems do not use a single turbine, they use multiple ones to achieve a higher output. Without pumps or special themal fluids and their storage, this is a much simpler system to operate and maintain. Thermal storage in sand has proven enough to drive the turbines at night. 

http://www.gov.cn/english/2010-12/28/content_1773883.htm


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## woodgeek (Jul 29, 2011)

Fascinating.  The mongolian plan covers 2.7 million square meters, with a stated power output of 27 megawatts, corresponding to an eff of <1.5% or so!  The projected project cost is $200 Million, or >$7/watt, not very impressive for equipment and construction costs in a chinese rural area.  The stated power for the prototype corresponds to 2000 hrs/year of full power production, or 25% duty cycle.  This is the same as a flat plate with perfectly clear skies, so the effect of storage is apparently pretty small.  In the US, the low eff would make the land use costs and enviro impacts unacceptable.

The low eff is presumably because of thermodynamic limitations on the low quality heat, and the high degree of thermal leakage through the flat plate glazing.
I also remain skeptical that turbines sitting in a high temperature dusty airstream will be maintenance free, compared to a PV array. And then there is the issue of keeping 2.7 km^2 of horizontal glass clean during the dust storms that frequent the Gobi desert!


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