Could Enough PV Significantly Cool the Desert?



Because the losses are multiplicative, not additive.
If you have two things that are 80% efficient, you wind up with 64% of what you started with.

The sin (theta) losses and the reflective losses, which multiply together.

If it is impossible now, it is because there is not enough water.
There are LOTS of crops that just love the full heat of the desert if you can get enough water to them.
PV panels will not make water magically appear.
--
Jim Pennino

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Where did the 80% figure come from?
Besides, it's as easy to clean 2 surfaces as one.

em

.
You don't think tracking is possible with grating or reflectors?

That wasn't true even back before 35 cent/watt PV.

Only alfalfa & hay. Nothing humans eat except napolitos.

PV + reverse osmosis = fresh water.
Bret Cahill
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It is an example, as is indicated by the sentence starting with the word "if".

No, it obviously takes twice the effort somewhere, either in machinery to do it automatically or labor to do it manually.

Once again, you need to learn the difference between "possible" and "practical".

The price of PV panels has nothing to do with the availability of water.
Are you on drugs?

Well, actually there are lots of things humans eat that grow just fine in very hot places. And there is also cotton, which is a major crop by itself.

Neither PV panels nor reverse osmosis will make water magically appear where there is none to start with.
Are you on drugs?
--
Jim Pennino

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And HVAC power lines lose 10% of their energy to resistance heating over just 200 miles.
What's your point? That it was a mistake to build transmission lives?
Anyway the plant problem in the summer here is _too much_ solar energy frying the leaves.
The concentrating PV problem is _too much_ solar energy [with the wrong wavelengths] frying the panels.
It's the perfect dovetail: Just send the red and maybe a little blue light to the plants and just send the green light to the panels.
Bret Cahill
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Utter nonsense.

Mostly that you are a clown.

Nope, the problem with crops in the desert is the availability of water.
There are LOTS of crops that like really high temperatures if they have enough water.
Yet again, see the San Joaquin Valley happily growing about 13% of US crops in over 100 degree F heat.

The solution to that is to just not concentrate.

It is a cartoon scheme that does nothing for the base problem, i.e. not enough water.
--
Jim Pennino

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le.

The price of solar PV is dropping so fast soon no one will bother with tracking mechanisms and other nonsense unless land is at such a premium they need dual use of the sun:
Red light for crops and green light for solar PV.
The arguments for dual use aren't complicated:
1. Most solar energy is green and useless to crops. Why not use it for PV?
2. Plants won't grow in the summer desert sun. Crops only grow in the winter when there is _less light_, 30% shorter days, etc. Why not extend the growing season into the summer by sending unwanted solar energy to PV?
3. The same goes for PV as for plants. Why not keep the PV cool by sending the excess solar to the plants?
Using green light for solar PV is green in more ways than one.
Bret Cahill
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Yeah, keep telling yourself that.

You forget the blue-violet also needed by green plants.

Just cartoonish.

You mean other than the enormous cost of all that machinery?

Plants grow just fine in the summer desert sun of the San Joaquin Valley.
Of course, there is a HUGE system to get the needed water there.
<snip clown babble>
--
Jim Pennino

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tan

Are you projecting or fessin' up that you are too stoopid to figger out how to use reflectors?
Care to try again?
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OK, how's this?
You are a babbling idiot full of cartoon ideas that won't work in the real world.
--
Jim Pennino

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So you are admitting you are too stoopid to use reflectors so that PV panels may be oriented in any direction??
Bret Cahill
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Nope, that you are too childish to understand the huge cost of all that machinery to grow crops where there is no water in the first place or there would already be crops there.
--
Jim Pennino

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OK, then show how it's possible.
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Why?
It may be possible, but it is highly impractical because of all the sin (theta) and reflection losses plus the cost of all the tracking mechanisms required to get anything at all out of it.
Then there is the issue of you are attempting to minimize shadowing by putting up 2 to 3 times the area of "stuff" to create shadows.
And lastly there is the issue of there being no water in the first place or there would already be crops growing.
--
Jim Pennino

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Other than being somewhat thicker how would you even be able to tell the difference between conventional tracking PV and tracking PV designed to transmit red?
Bret Cahill
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Because your system started out with added mirrors and such to separate light and send it to different places, or did you forget that?
--
Jim Pennino

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Here, try again:
Other than being somewhat thicker how would you even be able to tell the difference between conventional tracking PV and tracking PV designed to transmit red?
Bret Cahill
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It is not just thicker, it has more total obscured area because you are adding mirrors and gratings as well as their support and tracking structures.
--
Jim Pennino

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What is "obscured area"?
Are you having difficulty understanding that a m^2 of sunlight can suppy a m^2 of red light to algae and a m^2 of green light to PV?
Did you flunk out of middle school geometry or what?
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An area obscured from the Sun, moron.

Where did algae come from all of a sudden?
Are you having difficulty understanding that your whole scheme is Rube Goldberg at best, economically insane, and the basic premise of growing crops around your Rube Goldberg scheme is idiotic because there is no water there in the first place?

Are you on drugs?
--
Jim Pennino

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