Comments on: Clean Wind Energy Tower Shares Plunge as Downdraft Tower Construction Plans Proceed

By: perejo

perejo — Sun, 09 Jun 2013 21:41:00 +0000

So, let me understand the concept here: You take hot, dry air and you spray a mist of water into it at the top of a very large tower. The mist evaporates and mixes with the air, thereby humidifying the air, which makes it lighter than the non-humidified air. How is it supposed to push the heavier air out of the way?

By: 3000 Foot Downdraft Energy Tower Planned by Israeli Professors on Mexico-US Border | Green Prophet

Fri, 18 May 2012 11:00:51 +0000

[…] Cleantech already received approval to lease land for this project and began seeking zoning approval a few days ago. But in the strange world of business economics, their progress was taken as bad news and Cleantech’s shares plummeted. […]

By: Bob_Wallace

Bob_Wallace — Fri, 06 Apr 2012 18:25:00 +0000

That’s not math. Just more hand-waving.

Pumping water, dealing with the concentrated brine, hardening the system against corrosion – those are more system costs and we’re seeing no numbers that indicated that this idea works under ideal conditions.

By: Gocheltree

Gocheltree — Fri, 06 Apr 2012 18:06:00 +0000

The water would be pumped from the Sea of Cortez. They would be securing permission from Mexico to pump the water to the southern border of the US

By: Stan

Stan — Wed, 28 Mar 2012 11:09:00 +0000

OMG!!!!!!!!!!! Another perpetual motion machine..”some of the power is used to run it, and the rest is net production”…and THIS one, doesn’t even use more than 2 forces of nature in concert….
This is yet another example of the emperor’s new suit of clothes.
So, it’s supposedly as powerful as 2 nuclear reactors? (2x1200MW each if they meant 2500MWH)
IT”S A GIANT SWAMP COOLER people!!!!!!!!!!!!!! The principle is the utilization of the latent heat of vaporization…very sorry folks….this displacement of air will NOT turn the equivalent of 1250 5 MW wind turbines at their nominal annual rate of output….come ON! The turbine blades would have to be almost a 1/3 of a million miles in diameter (1000x 300′) or 100×300’…30,000 miles… if there were 10 turbines in each tower.
Do they mean “2500MW EACH hour”?
I am rushing out to go to the NYSE and register my own inventions in renewable power to go public…OH BOY, I’m gonna be RICH!!!!!!!!!!!!

By: Bob_Wallace

Bob_Wallace — Tue, 27 Mar 2012 00:17:00 +0000

I think we need to establish a criterion for publication of concepts like this one…

“Show your math.”

How about a slightly higher threshold for new tech pieces? Hold back on the wild claims stuff and require better explanation of extraordinary claims….

By: James Van Damme

James Van Damme — Tue, 27 Mar 2012 00:00:00 +0000

“speeds up to and in excess of 50 miles per hour”…? BTW where is all this fresh water going to come from? You can pipe it in from Lake Ontario if you like, but it’s a long way to the desert.

By: dougt

dougt — Mon, 26 Mar 2012 17:44:00 +0000

kwh is “kilowatt – hr” or “kilowatt * hr”, not “kilowatt per hr”. The former is multiplied by hours, the later divided. This is not symmantic nitpicking, it is important.

and as to “Since when is the number of watts of energy used in an hour not a real measure?”… Watts are not an amount of energy, they are a rate of energy transfer. So saying you used 1 watt in an hour is meaningless as saying you drove 50mph in an hour The joule is the unit for an amount of energy. A watt is the transfer of one joule in one second. Thus a megawatt-hour is 1 million joules per second for one hour, or 3.6 billion joules. A megawatt per hour is nonsense unless you are talking about the ramp-up rate of energy transfer (which the manufacturer obviously isn’t.

By: Tom Cohenno

Tom Cohenno — Mon, 26 Mar 2012 14:55:00 +0000

Yes, a kWh is a commonly used term to talk about a unit of energy. But it terms of power production, we use the term “watt” ( or kilowatt, megawatt, or gigawatt). But to say that a power plant is capable of production “megawatts per hour” is meaningless. Now, if they claim to produce a certain amount of “megawatt-hours” per day or week or year, that makes sense. (Honestly I think this would all be much simpler if we would just use “joules” instead of “watt-hours”. )

Bottom line – We pay for and consume ENERGY (power for a certain amount of time). Power plants produce POWER (energy per unit time). Power per unit time has no meaning.

By: Tom Cohenno

Tom Cohenno — Mon, 26 Mar 2012 14:45:00 +0000

I completely agree that their website is an embarrassment to supporters of renewable energy. The claim that an energy production technology is capable of producing “megawatts per hour” suggests the lack of even a high school physics background. To be fair, I wondered if they just meant “megawatts”, but 1,500 megawatts is a HUGE amount of POWER. Maybe that is the case, but my impression is that one of these is not more powerful than a commercial nuclear reactor.

Also, as the humid, cooler air (in the middle of the desert!) falls across the “man-made” wind turbines (what else would they be? natural, wind carved turbines complete with naturally occurring ball bearings?).

What is the water consumption of this thing? Seems that even if it worked, the sheer amount of water used in the middle of the desert would counteract any environmentally beneficial aspect of clean electricity production.

Don’t get me wrong – I’m a huge supporter of renewable energy technology and think that eventually it should and will provide a large part of our energy portfolio – BUT, I’m not buying any of this stock.

By: Dcard88

Dcard88 — Mon, 26 Mar 2012 12:37:00 +0000

What are you talking about. kWh is used millions of times a day by every renewable co in the world. Since when is the number of watts of energy used in an hour not a real measure?
http://en.wikipedia.org/wiki/Kilowatt_hour
I dont claim to be a scientists, but this makes you the replier seem less than knowledgeable.

By: Akbweb2

Akbweb2 — Mon, 26 Mar 2012 05:28:00 +0000

Thanks, Doug. Their use of this (meaningless) unit )MW per hr.) had me perplexed…

but I figured they must know what they’re talking about, having been able to raise all that capital! Big mistake perhaps…and that’s all I had to go on at time of writing…

That’s the beauty, and power, of science and mathematics, I guess…Thanks for cutting through the fog on that, and going further to look at the make-up of management…

By: dougt

dougt — Mon, 26 Mar 2012 00:19:00 +0000

What the heck unit is “megawatt per hour”???? I know what a “megawatt – hr” is (that would be 3.6 gigajoules) and I know what a “megajoule per hour” is (that would be an averge power of 278 watts over a period of an hour), but “megawatt per hour” is meaningless as a unit of energy production. It’s not very confidence building that the company’s website also uses the unit on their website.

The unit makes no sense unless you are talking about the maximum power rampup speed of a system, which is irrelevant in this context.

If this sort of gross technical incompetence gets onto the company’s website, I really wonder about their design. Looking at the list of company executives, I don’t see a CTO or any reference to a reputable technical expert. Its all marketing and finance peope…big red flag. They raise capital, pay themselves well in cash and stock options, cash out the options, and let the company crash…repeat with new company. Wether they build the thing or whether it works is irrelavent, all they care about is creating buzz that will bring investment.