solar tower power generation (Mega Project)

[Ecoman]

Obviously it will be done in Arizona

however, the principle seems very different.

I do not understand well, the air circulation is from top to bottom ....

http://www.insidetucsonbusiness.com/news/arizona-town-to-get-solar-wind-energy-tower/article_3f7bea62-1db3-11e4-9635-001a4bcf887a.html

http://www.solarwindenergytower.com/

[Gaston]

however, the principle seems very different.

I do not understand well, the air circulation is from top to bottom ....

Because we inject water to cool the air.

[I Citro]

Google tradution ... But we understand the main lines:

Pickett said the Downdraft Tour solar wind is the first solar wind hybrid renewable energy technology on the market. The patented structure consists of a very tall hollow cylinder with a water injection system near the upper wind tunnels and containing wind turbines near the bottom.

A series of pumps provide water to the tower injection system at the top where a fine mist is diffused over the entire opening. The water introduced by the injection system, says Pickett, evaporates and is absorbed by the hot and dry air which has been heated by the sun's rays.

Result, the air becomes cooler, denser and heavier than hot outdoor air, and falls into the cylinder at speeds of up to and beyond 50 miles per hour (over 80kmh). This air is then diverted into blowers that surround the base of the tower where the wind turbines inside the tunnel generator sets to generate electricity.

Pickett said he expects the project to have 60 tunnels with 120 turbines and 30-chamber generators. Eleven generators in each generation chamber each will produce from 500 kilowatts to 10 megawatts of electricity, depending on their design. The tunnels, Pickett noted, "are a few hundred feet long and have a radius of about 35 feet from the turbines."
Pickett said the Downdraft Tour solar wind is the first solar wind hybrid renewable energy technology on the market. The patented structure consists of a tall hollow cylinder with a water injection system near the upper wind tunnels and containing wind turbines near the bottom.

A series of pumps provide water to the tower injection system at the top where a fine mist is thrown over the entire opening. The water introduced through the injection system, Pickett says, evaporates and is absorbed by the hot, dry air that has been heated by the sun's rays.

The result is the air becomes cooler, denser and heavier than warm outdoor air, and falls into the cylinder at speeds of up to and beyond 50 miles per hour. This air is then diverted into blowers that surround the base of the tower where the wind turbines inside the tunnel generator sets to generate electricity.

Pickett said he expects the project to have 60 tunnels with 120 turbines and 30-chamber generators. Eleven generators in each generation chamber each will produce from 500 kilowatts to 10 megawatts of electricity, depending on their design. The tunnels, Pickett noted, "are a few hundred feet long and have a radius of about 35 feet from the turbines."

Apparently, it seems that the gain in production brought by the injection of water justifies its use ...

However, we must remain cautious about the environmental and health consequences of this installation, due to the enormous consumption of water and the risk of legionellosis that it represents.

Can we not recycle part of this water by condensing it in one way or another?

[Ecoman]

Yes, but the basic principle of the solar cheminey was that ... hot air rises.

Here I do not really understand the interest of doing the thing in arid zone, what difference does it make if it is to cool the air with water, if it is found we would do the same in non-arid zone ? hence my questioning

[I Citro]

The answer lies in performance.

I am not an engineer, but I think that it is necessary to reason in DDP (potential difference).

- When using an energy source, we strive to have a low PDD, this is the principle of low temperature heating, more efficient than high temperature boilers.

- When we extract energy from a medium, we strive to have a large PDD.

I have put in bold the considerable speed obtained in the tower (more than 80kmh).

I think that to obtain such speeds on a "classic" thermosyphon tower, there are only 2 solutions (except for an optimal geographical configuration):

-1 / Increase considerably the height of the tower so that it opens at an altitude where the air is less hot. We say that we lose 10 ° C every 1000m altitude.

-2 / Increase considerably the air temperature at the base of the tower, this is the reason for the construction of greenhouses at the foot of the tower to heat and channel the admitted air.

A third avenue would be to extract calories from the humidity in the air. This is the principle of enthalpy exchangers, as we find in some VMC double flow from Helios.

[Ecoman]

There are no greenhouses in this project if you look at it.

All the more reason if there is a 10 ° difference every 1000 m (I didn't think so much)

Bringing down the air seems incomprehensible

[moinsdewatt]

It seems to me delusional, to inject water in a desert area (Arizona)!

Which river or aquifer will they pump?

[Ecoman]

They say that it will not consume more than the farm that was there before, nevertheless, I still do not understand the principle in any case if it is done at 1,5 B USD is that it must work

[highfly-addict]

They say that it will not consume more than the farm that was there before, nevertheless, I still do not understand the principle in any case if it is done at 1,5 B USD is that it must work

Citro explained it well above. We are looking for DDP to extract energy.

In "rising air", you need a gigantic tower to get the cold temperatures at altitude, and put greenhouses at the foot to further increase the DDP.

In "descending air", one is satisfied to go to seek the top of the hot layer, the increase of the DDP works naturally in the other direction: to cool the air at the top of the tower.

Conclusion: a gigantic tower + hectares of greenhouses against a much more modest size tower and a pump system.
On the economic level the second solution seems the best ...

[Ecoman]

and yes necessarily the hot air goes up, the cold air must logically go down ...

In any case this solution must be better since the project seems to be done