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Ivanpah Solar Electric Generating System

04/17/2014 11:18 AM

Driving I-15 south into California from Nevada, this installation is impossible to miss - at least during the day.

It's the Ivanpah Solar Electric Generating System.

The two lit towers are quite bright, surpassed only by the Sun. They look like large banks of powerful halogens, brighter than any stadium bank.

The "halos" you see in the photo are quite visible to the naked eye. I wonder what they are. The answer is not immediately clear on the web site. My theory is the heat of the concentrated sunlight is ionizing air molecules. Anyone else have a plausible explanation?

Looking around, I was struck with how small the plant looked in the vast, empty desert. There could have been dozens of towers with their mirrors placed within the valley. Yes, the desert ecosystem is fragile, but in terms of mere area, it seems a waste of space. Compared to a coal-fired plant (which you will also see driving the long, straight highways of the West), it's a pretty clear choice to me.

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#1

Re: Ivanpah Solar Electric Generating System

04/17/2014 12:39 PM
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#2
In reply to #1

Re: Ivanpah Solar Electric Generating System

04/17/2014 12:46 PM

If you're suggesting that the halos are steam, I don't think so. They did not flux or float. They're just... there. The desert air is very arid, leading to rapid evaporation of any water vapor. Here's a zoom-in of the dark tower that shows them more clearly.

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#3

Re: Ivanpah Solar Electric Generating System

04/17/2014 12:49 PM

There may be some ionization taking place but I think mainly this is reflected light from dust particles and moisture in the air....

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#5
In reply to #3

Re: Ivanpah Solar Electric Generating System

04/17/2014 5:33 PM

I'll buy that for a GA vote.

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#4

Re: Ivanpah Solar Electric Generating System

04/17/2014 5:30 PM

It's an optical delusion.

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Power-User

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#6

Re: Ivanpah Solar Electric Generating System

04/18/2014 12:38 AM

It is the dust particles in the air. On windy days it is different from the few days that the wind does not blow. The effect may also be from dirt on the mirrors that cause an error in the relection so that some of the reflected sunlight actually misses the collector. But most of it is dust in the air relecting the light. If the dust were not there, you would not see the light in that area.

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#7

Re: Ivanpah Solar Electric Generating System

04/18/2014 10:55 AM

I've seen this from the air. In January, flying into LAX, I saw three sun-intense lights on the ground. From how far out we were, and having driven by this facility many times while it was being built, I figured it was Ivanpah. It left little purple dots in my vision. While flying out of LAX a few weeks later, the pilot notified "if you look out the left side of the aircraft you will see the solar plant near Primm." So, like the Grand Canyon, this place is now a landmark for flyers.

FAA has received a complaint from those flying out of airports very near the facility:

http://www.allgov.com/usa/ca/news/california-and-the-nation/pilots-say-glare-from-newly-opened-ivanpah-solar-farm-is-blindingly-dangerous-140319?news=852711

http://www.earthweek.com/2014/ew140321/ew140321x.html

I had speculated that mirror misalignment was causing the reflected light to miss the towers altogether. I am happy to see the dust explanation. This has still got to cause an efficiency loss.

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#8

Re: Ivanpah Solar Electric Generating System

04/18/2014 2:30 PM

From Wikipedia:

"The project cost $2.2 billion and the largest investor in the project is NRG Energy, a generating company based in Princeton, N.J., that has put in $300 million.[8] The project has received a $1.6 billion loan guarantee from the United States Department of Energy.[9] The estimated construction costs for this CSP project ($5,561.00 per KW) fall between the construction costs for coal and nuclear power plants per Synapse Energy Economics,[10] [11] but that does not account for the much lower capacity factor of solar power."

Huh..? Capacity factor ???? What does that mean ..??? Does that have anything to do with the amount of time that the plant can be relied upon to produce power ???

You state:

"Compared to a coal-fired plant (which you will also see driving the long, straight highways of the West), it's a pretty clear choice to me."

Well , I don't think that it is a simple choice....red pill or blue pill..... YOU NEED BOTH !

For the times that you need power to stabilize and supply the need of the grid, YOU MUST HAVE SOMETHING ELSE !

Oh,..... and by the way..... who pays for that carbon or nuclear reserve power plant that must be there to make the entire system work ?

Doesn't that reserve power cost ADD to the cost of solar generated electricity ?

Oh yes, and at $5000 to $6000/kw, isn't this an especially expensive way to go ?

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

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#9
In reply to #8

Re: Ivanpah Solar Electric Generating System

04/18/2014 3:16 PM

What you mention is somewhat short sighted. In many areas of the west where water power was developed, the drouts in recent years have forced them to either curtail production or highly reduce electric production from installed dams. The Solar and wind installations can allow the production of the stored reserve of water power to be offset with these sources and this works out quite well. There are also solar installations where the heat is stored for 24 hour production of power. Renewables have their place in the system.

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#10
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Re: Ivanpah Solar Electric Generating System

04/18/2014 3:23 PM

So we need to consider that hydro is similar to solar and wind in that its availability fluctuates with the whims of Mother Nature?

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#11
In reply to #10

Re: Ivanpah Solar Electric Generating System

04/19/2014 5:03 PM

Yes you do, that's why utilities that rely on hydro also have fossil/nuclear plants to provide for times of low flow. Fortunately forecasting low water conditions is easier and more reliable then predicting the minute by minute vagaries of wind and solar.

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#12

Re: Ivanpah Solar Electric Generating System

04/28/2014 12:00 PM

Halos around the collector towers: (1) dust particles in the general area make a contribution, and (2) Raman scattering at high intensity incident by small molecules of oxygen and nitrogen (this is a second-order effect, only observed at high intensity). Moisture content in the air is quite low relative to these. Depending on how much dust has been stirred up, the dust could even be below the Raman scattering effect at the high incident light condition observed. It is quite interesting. You can see something of this effect at low levels on the horizon in the photo - mostly from atmospheric dust.

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#13
In reply to #12

Re: Ivanpah Solar Electric Generating System

04/28/2014 3:11 PM

Interesting. I'd never heard of Raman scattering. Could this be one of a very few real-world images of such a phenomenon then? Google image search provides only diagrams and lab photos.

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#14
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Re: Ivanpah Solar Electric Generating System

04/28/2014 3:56 PM

Probably so. Rayleigh scattering is light scattering by a colloidal suspension (of dust particles so small they are typically "invisible") and/or molecules. Rayleigh scattering is responsible for red sunsets and sunrises, and for blue sky. Raman scattering is a second-order effect in electro-magnetic field strength, whilst Rayleigh scattering is related to the frequency of the light to the fourth power (and upon the presence of a colloid). Since the light scattered by Rayleigh scattering is polarized, the tower "halos" might be seen to dim by rotating a polarizing optic element in the field of view. I am not aware that Raman scattering is polarized. Raman scattering is wavelength independent (as to the incident source), and is an inelastic scattering (change of photon energy scattered by vibration-rotational band of molecule). Rayleigh scattering is wavelength dependent (as previously mentioned), yet is elastic scattering (no change in photon energy), and flourescence required an electronic state resonance (or vibration-rotational state resonance), and hence does not apply across the entire visible spectrum (for the set of molecules typically in air).

I am still wagering this halo is primarily Raman scattering, since it "appears" as a "white" halo, and not a "blue" halo. Perhaps a simple camera polarizing filter can resolve the issue.

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#15
In reply to #14

Re: Ivanpah Solar Electric Generating System

04/28/2014 6:18 PM

Well, now I wish I'd rotated my polarized lenses at it. Too bad it's 600 miles away.

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#16
In reply to #15

Re: Ivanpah Solar Electric Generating System

04/29/2014 9:12 AM

I guess we could call them up and find out. I know it's not angels.

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