About Solar Chimneys

Solar chimneys, are one of the least publicized forms of solar power plants.  The power plant consists of a very large glazed solar collector with a chimney in the center through which the hot air generated in the collector rises.  The hot air wind drives turbo-generators located at the base of the chimney.  The floor of the collector, is lined with heat absorbing media, which absorb heat during the daytime and release the heat during the night, so that the power is produced on a continuous basis.  Cold air enters the collector, with an upward sloping ceiling, from its outer perimeter, is heated and rises through the tower at 50 feet per second (15 meters per second).  The solar tower works on the principle that the higher temperature of the air in the collector compared to the outside temperature causes a density difference, which causes the air, heated to about 100 ^oF (38^oC) hotter than the outside air, to rise, creating a solar wind that drives the turbines. 

Recent improvements in the conceptual design, specifically, potential improvements in the performance of the roof area of the collector and a new method of storing heat have enabled modularization to units as small as 25  megawatts (MW).  The smaller units are said to greatly reduce development costs, while still providing much lower capital costs for larger installations. Having a shorter chimny (still very tall) will reduce the profile of the plant which should reduce permiting and regulatory problems.  Solar tower power plant modules, unlike most forms of renewable energy, produce a very significant quantity of electricity, 25 to 200 MW or more.  The two disadvantages of the system are that they requires a large land area and are quite expensive.

A 50 kw demonstration prototype was built in Spain in the 1980's and operated for seven years.  A 200 megawatt plant, described in this 2001 article from Wired, has been under development in Australia for the last five years by EnviroMission Limited.  A recent announcement was made by the California parent company, SolarMission Technologies, that it is going to "build, own, maintain and operate 2,600 megawatts of solar towers".  A group of Chinese investors has invested US$2 million in the project's development.  There are also plans to invest a further US$8 million for development of a solar tower in China.

A more detailed description of the process can be found here at the SolarMisssion website. On Feb. 10, 2005 SolarMission was to purchase the site in Australia for the first plant.  Details for a 200 MW Solar Tower power station are as follows (details have not been released for the 25MW module):

• Tower: 3000 feet high, 400 feet Diameter
• Concrete: 750,000 cubic yards
• Collector: 3.5 miles in diameter, glass/polycarbonate/plastic film
• Turbines: 32 units, 6.25 megawatts each.
• Land: 20.25 square miles
• Construction time: 34 months
• Jobs: Construction 2,700+, 15 ongoing
• Output: 200 megawatts.

Several options are available for the operation of the plant.  By placing a shutter in the tower the hot air can be released at the most desirous time: during peak power demand or it can be throttled during the day so as to maintain an even flow throughout the 24 hour day providing perhaps a better base load plant.  The size of the collector can be varied to allow more or less heat to be collected during the day for use at night or for periods when the sun is covered with clouds.  The amount and type of heat storage media can be varied to increase the collectors ability to store heat.

Two of the real advantages that I see for the system are that it runs continuously and it should require minimum maintenance.  The only significant machinery are the wind turbines and generators which are very well developed.  The modular nature of the turbines and generators could mean that they could be maintained one module at a time with little, if any, interruption to the plants operation.

I would like to acknowledge the Alternative Energy Blog whose June 1 post brought this technology to my attention.

Technocrati tags: solar energy, renewable energy, solar chimneys

Comments

[Nick]

Do we have any overall or per KW cost info?

[donald alves]

what type of calculations do they make regards to wind speed needed to turn the turbine and heat tranfer in the greenhouse area

[asil]

various artists
komik resimler
gül resimleri
asp script indir

[piyush]

DURING RANISEASON IN WHAT WAY THE SYSTEM CAN WORK

[MAUGIS]

If you want to know more about much powerfull solar chimney, please look at: http://cdurable.info/spip.php?action=redirect&id_article=547

François MAUGIS

[Dick Moyer]

I wonder why in prime solar areas, as those in Luna and Hildago counties in south western New Mexico, where there seems to be a very considerable activity by as many as thirty individuals and companys trying to tie up very large parcels of land, as I under stand it, hoping to generate solar power cheap enough to negotiate power purchase agreements, cheap enough to transmit to California. I wonder why go to this extent to produce power cheap enough to sell it for very long distance, sustaining a considerable power loss in transmission? When manufacturing company's move all over the world seeking low cost power, why would it not make sense if the land is cheap, and the optimum area for solar production, rather than wholesale it at a very low price, why not offer competitive land prices to manufacturers, to move to that area, and guarantee them a price per kw, guaranteed for perhaps fifteen or twenty years, and be better off than struggling to offer low ball prices to power company's ?

[Dick Moyer]

I wonder why in prime solar areas, as those in Luna and Hildago counties in south western New Mexico, where there seems to be a very considerable activity by as many as thirty individuals and companys trying to tie up very large parcels of land, as I under stand it, hoping to generate solar power cheap enough to negotiate power purchase agreements, cheap enough to transmit to California. I wonder why go to this extent to produce power cheap enough to sell it for very long distance, sustaining a considerable power loss in transmission? When manufacturing company's move all over the world seeking low cost power, why would it not make sense if the land is cheap, and the optimum area for solar production, rather than wholesale it at a very low price, why not offer competitive land prices to manufacturers, to move to that area, and guarantee them a price per kw, guaranteed for perhaps fifteen or twenty years, and be better off than struggling to offer low ball prices to power company's ?

[Kit P]

“I wonder why ...”

Consider for a moment Dick that polices to promote renewable energy by loons in California are really stupid and worse for the environment than a coal with no emissions controls.

The first concept is solar power is not cheap, it is mandated. Industry moves to place where there are reasonable mandates. Several large energy users are locating in places like Idaho and New Mexico. Also many renewable energy projects are locating in the west outside of California. States other than California get the jobs and the property taxes.

Generating projects put electricity into the grid. Consumers use electricity from the grid. Only the lawyers can tell where the electricity came from. If you consume electricity generated under a gigh price contract, you pay more.

If there happens to be a 1000 MWe coal plant between you and your expensive power, guess where your power really comes from?

[Bob Wallace]

Kit, I wish you would quit being such a prick.

You seem to have some useful information to share, but you are so insulting to others that I just don't want to read your stuff.

Would you please make a concerted effort to play nice with others?

It would make this site a lot more useful and enjoyable if we could discuss topics without throwing crap-balls at each other.

[Bob Wallace]

Dick, with HVDC (high voltage direct current) transmission lines we can move lots of power long distances with minimal losses.

Here's something on the Pacific DC Intertie that moves power on the west coast.

http://en.wikipedia.org/wiki/Pacific_DC_Intertie

The plan might be to move power from where it is cheap to produce north or west to larger cities. Or it might be to connect up with the transmission lines which will hook Texas wind farms eastward.

Some day we are likely to see the Pacific Intertie hooked eastward as we connect the nation. Lots of sun in the Southwest during the day, lots of wind in the Great Plains at night....

[Kit P]

Here is a solution for you Bob. When you see my name at the bottom of a post, just skip past it. Clearly there are loons in California that actively promote bad energy policy and I will continue to point that out. I will never know.

[Cyril R.]

Quote Kit P: "When you see my name at the bottom of a post, just skip past it."

Exactly.

[Solar Power Installation]

Thanks for this wonderful post

[wholesale dropshippers sources vendors]

this is so cool. wow everything is getting better in time.

[varun pratap singh]

hi,
i have one more concept related u r project
plz contect..
send me u r drawing n design details.

[Wholesale Solar]

An incredible thing about this new technology is the simplicity of its design, and its ingenious use of basic principles of physics to create energy.

Thanks for your excellent post.

Wholesale Solar

http://www.wholesalepages.co.uk/