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#11
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You should see the solar towers southwest of Primm, NV (just inside CA),
USA. The top of the tower, surrounded by acres and acres of focused mirrors appears to glow white hot. You can also see a dark cloud around the tower. I wonder if that's plasma from super heated air or just the remains of passing bugs and birds... "John Firth" wrote in message ... I bet desalinated water is more valuable in Arizona as irrigation or domestic supply; unbelievable. The downdraft tower would be the inverse of the Australian 1km solar power tower; I have seenno news since 2011. JMF At 15:38 29 October 2013, Dan Marotta wrote: They said they'd pump "desalinated" water, so there's gonna be quite some construction and energy expense on the intake end, as well. And a nuclear reactor wouldn't be near as expensive, I'd wager, were it not for the DOE. Remember, the government couldn't make a profit running a whore house that also sold whiskey in Nevada, so why should we believe they make a better nuclear plant? "Dave Springford" wrote in message ... The first article is a technically better where it shows the evaporative cooling creating the down draft, so that part has been explained. It also says the water will be brought in from the Sea of Cortez 48 miles away. So what's the cost model for building a pipe line and pumping water 48 miles? substantially cheaper than a nuclear reactor, I guess. This project would seem to be significantly more expensive than regular wind turbines - not that we like those either. |
#12
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![]() here's a follow up article with frequently asked questions answered (like How can humid air create a downdraft? ) http://www.forbes.com/sites/davidfer...ions-answered/ |
#13
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![]() I don’t understand the explanation of how this works. The article says that making the air moist makes it heavier. When I was at school I was taught that water vapour is lighter than air and that moist air is less dense than dry air so why would making the air moist cause it to sink? I think the people who wrote the article don't quite understand how this works. Surely its the evaporation that is important rather than the wetting of the air. At 15:57 17 November 2013, Dan Marotta wrote: You should see the solar towers southwest of Primm, NV (just inside CA), USA. The top of the tower, surrounded by acres and acres of focused mirrors appears to glow white hot. You can also see a dark cloud around the tower. I wonder if that's plasma from super heated air or just the remains of passing bugs and birds... "John Firth" wrote in message ... I bet desalinated water is more valuable in Arizona as irrigation or domestic supply; unbelievable. The downdraft tower would be the inverse of the Australian 1km solar power tower; I have seenno news since 2011. JMF At 15:38 29 October 2013, Dan Marotta wrote: They said they'd pump "desalinated" water, so there's gonna be quite some construction and energy expense on the intake end, as well. And a nuclear reactor wouldn't be near as expensive, I'd wager, were it not for the DOE. Remember, the government couldn't make a profit running a whore house that also sold whiskey in Nevada, so why should we believe they make a better nuclear plant? "Dave Springford" wrote in message ... The first article is a technically better where it shows the evaporative cooling creating the down draft, so that part has been explained. It also says the water will be brought in from the Sea of Cortez 48 miles away. So what's the cost model for building a pipe line and pumping water 48 miles? substantially cheaper than a nuclear reactor, I guess. This project would seem to be significantly more expensive than regular wind turbines - not that we like those either. |
#14
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Why build an expensive rigid structure? A central mast like a radio tower could be built tall enough for a tiny cost fraction. Reinforced canvass sides to form an octagonal "cooling tower" could be supported from the mast, and even lowered in the event of strong winds. No, I have not worked out the dynamics of this system - not even sure if it could work, especially if the air pressure inside the tower is lower than the surrounding air pressure from Bernoulli effects.
This still leaves the several previously mentioned issues, plus a few more, like 1) Where to get water (assume that it is untreated and full of minerals) 2) Mineral deposits all over the generator equipment 3) Pumping energy losses - to get all that water 2200 feet up in the air 4) Power transmission lines to a remote area |
#15
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On Sunday, November 17, 2013 7:57:45 AM UTC-8, Dan Marotta wrote:
You should see the solar towers southwest of Primm, NV (just inside CA), USA. The top of the tower, surrounded by acres and acres of focused mirrors appears to glow white hot. You can also see a dark cloud around the tower. I wonder if that's plasma from super heated air or just the remains of passing bugs and birds... Watch the low thermalling! |
#16
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At the risk of sounding political...
Someone comes up with a way to make a lot of money off of those who don't know any better, but it sounds like it'll save the planet from demon coal, oil, and nuclear power. Does Solyndra ring a bell? Let's see... Billions of public money. Use of public lands for private enterprise. Untested technology. Mineral laden water (or the energy expense of demineralization). International pipeline. Probably kill some endangered diatom or algae. Drain the Sea of Cortez, thus changing the center of gravity of the earth, causing it to begin wobbling on its axis and hurtling out of its orbit onto a collision course with the sun. Wait a minute... Closer to the sun means better thermals! Damn the torpedoes, let's do it! "Cedric Sponge" wrote in message ... I donâ?Tt understand the explanation of how this works. The article says that making the air moist makes it heavier. When I was at school I was taught that water vapour is lighter than air and that moist air is less dense than dry air so why would making the air moist cause it to sink? I think the people who wrote the article don't quite understand how this works. Surely its the evaporation that is important rather than the wetting of the air. At 15:57 17 November 2013, Dan Marotta wrote: You should see the solar towers southwest of Primm, NV (just inside CA), USA. The top of the tower, surrounded by acres and acres of focused mirrors appears to glow white hot. You can also see a dark cloud around the tower. I wonder if that's plasma from super heated air or just the remains of passing bugs and birds... "John Firth" wrote in message ... I bet desalinated water is more valuable in Arizona as irrigation or domestic supply; unbelievable. The downdraft tower would be the inverse of the Australian 1km solar power tower; I have seenno news since 2011. JMF At 15:38 29 October 2013, Dan Marotta wrote: They said they'd pump "desalinated" water, so there's gonna be quite some construction and energy expense on the intake end, as well. And a nuclear reactor wouldn't be near as expensive, I'd wager, were it not for the DOE. Remember, the government couldn't make a profit running a whore house that also sold whiskey in Nevada, so why should we believe they make a better nuclear plant? "Dave Springford" wrote in message ... The first article is a technically better where it shows the evaporative cooling creating the down draft, so that part has been explained. It also says the water will be brought in from the Sea of Cortez 48 miles away. So what's the cost model for building a pipe line and pumping water 48 miles? substantially cheaper than a nuclear reactor, I guess. This project would seem to be significantly more expensive than regular wind turbines - not that we like those either. |
#17
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On Sun, 17 Nov 2013 08:57:45 -0700, Dan Marotta wrote:
You should see the solar towers southwest of Primm, NV (just inside CA), USA. The top of the tower, surrounded by acres and acres of focused mirrors appears to glow white hot. You can also see a dark cloud around the tower. I wonder if that's plasma from super heated air or just the remains of passing bugs and birds... That's a very different beast which uses direct radiant solar heating to heat a boiler. The French used a similar system as a solar furnace, which NASA used to test Mercury program heat shields: http://en.wikipedia.org/wiki/Solar_furnace The type of solar chimney that the Australians were planning but never, AFAIK, started to build and that the Spanish built as a 50kW experiment and ran for eight years is almost exactly the inverse of the GE proposal. Where GE would evaporate water at the top of a 2000 ft tower to cool the air and cause a downflow to spin turbines as it exits the base of the tower. OTOH the Spanish/Australian approach surrounded the bottom of a similarly high tower with a wide area of glass solar roof. This causes sunlight to warm the air under the roof, which flows inwards and up the tower thanks to the chimney effect and, in the process spins turbines mounted inside the tower fairly close to its base. The designers have a choice of using bare, blackened ground under the solar roof for maximum efficiency or of accepting a bit less efficient generation, but making the solar roof serve double duty by raising low-growing crops under the roof. The Spanish experiment at Manzanares was a bit shorter - 195m, say 640ft. Here's a reference to it: http://www.sbp.de/en#sun/show/82-Sol...ant_Manzanares There's a more general coverage of the idea and various projects, either running or planned, he https://en.wikipedia.org/wiki/Solar_updraft_tower -- martin@ | Martin Gregorie gregorie. | Essex, UK org | |
#18
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On Mon, 18 Nov 2013 09:34:17 -0700, Dan Marotta wrote:
At the risk of sounding political... Someone comes up with a way to make a lot of money off of those who don't know any better, but it sounds like it'll save the planet from demon coal, oil, and nuclear power. Does Solyndra ring a bell? Let's see... good reasons for doubting it chopped The question that needs answering is why dive in with an untested technology when its opposite, the solar UPdraft tower, is known and tested technology. There is a decent summary (with numbers) of solar downdraft technology he https://en.wikipedia.org/wiki/Solar_downdraft_tower and similar detail of its opposite he https://en.wikipedia.org/wiki/Solar_updraft_tower I think these points are also worth looking at: - the energy cost of pumping water to the top and spraying into the tower has been estimated as about 50% of the turbine's output, but AFAICT that excludes the cost of desalinating the sea water and pumping it to the base of the tower. Desalination is energetically expensive, so the overall system efficiency might be very small or even negative. - against that the solar updraft tower has the cost of building and maintaining a large solar roof at its base, but only maintenance costs thereafter. The 50kW Manzanares pilot project had a 0.53% efficiency, but calculations show a more modern 100kW unit might reach 1.3% - Billions of public money. A key point: always follow the money! Are the project sponsors putting their money where their mouth is? -- martin@ | Martin Gregorie gregorie. | Essex, UK org | |
#19
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On Monday, November 18, 2013 3:40:35 PM UTC-6, Martin Gregorie wrote:
On Mon, 18 Nov 2013 09:34:17 -0700, Dan Marotta wrote: At the risk of sounding political... Someone comes up with a way to make a lot of money off of those who don't know any better, but it sounds like it'll save the planet from demon coal, oil, and nuclear power. Does Solyndra ring a bell? Let's see... good reasons for doubting it chopped The question that needs answering is why dive in with an untested technology when its opposite, the solar UPdraft tower, is known and tested technology. There is a decent summary (with numbers) of solar downdraft technology he https://en.wikipedia.org/wiki/Solar_downdraft_tower and similar detail of its opposite he https://en.wikipedia.org/wiki/Solar_updraft_tower I think these points are also worth looking at: - the energy cost of pumping water to the top and spraying into the tower has been estimated as about 50% of the turbine's output, but AFAICT that excludes the cost of desalinating the sea water and pumping it to the base of the tower. Desalination is energetically expensive, so the overall system efficiency might be very small or even negative. - against that the solar updraft tower has the cost of building and maintaining a large solar roof at its base, but only maintenance costs thereafter. The 50kW Manzanares pilot project had a 0.53% efficiency, but calculations show a more modern 100kW unit might reach 1.3% - Billions of public money. A key point: always follow the money! Are the project sponsors putting their money where their mouth is? -- martin@ | Martin Gregorie gregorie. | Essex, UK org | So many answers in the latest link Bill Palmer provided. And so many flaws continuing. And, getting worse. In answer to your question, Martin, "No, the project sponsors are NOT putting their money where their mouth is." To quote the article, "Pickett said the company wouldn’t need to generate much of its own capital because it would license the technology to a project developer. The company is in talks with “a very credible, notable development company noted for its energy accomplishments,” Pickett said." Hey, I have this great idea for turning your money into my money... |
#20
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Oh, and since it will have cold air blowing out the bottom of it, this should help stop global warming. :-)
Now, where is the white paint so I can paint all those asphalt roads that are causing global warming.... |
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