Global warming and solar energy

[Duer 157099]

There's a thread over here:

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=102x2249611

that talks about a plan to install a HUGE solar farm in New Mexico.

Then, the thought occurred to me:

If we seriously ramp up the use of solar panels, is there any chance that this will have an effect on global warming? I mean, perhaps this would be one way to offset even just a tiny fraction?

Or maybe I'm not undestanding global warming enough

[benburch]

1. Well, it does change the albedo of the planet a little.

But cities and roads and plowing fields are SO much larger a change that I don't think that you will notice the solar farms.

And if we DID go to using all solar, we would stop adding CO2 to the atmosphere, and that would vastly overpower any albedo change from sun farming.

[Duer 157099]

2. You win Ben. You are the very first DUer who has

sent me to the dictionary!! Seriously, that was good.

But, there are two definitions, and I'm having difficulty deciding which one you meant:

1. The fraction of incident electromagnetic radiation reflected by a surface, especially of a celestial body.
2. The spongy white tissue on the inside of the rind of citrus fruit.

:-)

[BrklynLiberal]

4. I had to look it up about 30 years ago when I got Vangelis' Albedo 0.39

The title refers to the average albedo (electromagnetic reflectancy) value of planet Earth.

[dweller]

7. sounds like the same thing

if you can picture the earth as the meat of a fruit.

dp

[benburch]

9. LOL!

Remember those science demonstrations?

"This orange represents the Earth. This Apricot on the edge of my desk is the moon in the same scale. I've placed a small peach on the wall at 5th and Main, and that is Mars..."

[Dead_Parrot]

3. It would be nice...

But PV's stupidly expensive. the "300 megawatts of electricity while the sun shines" (and remember, 0 megawatts when it doesn't) is a fraction of what you'd get from spending the same money on a windfarm, small nuclear plant or geothermal plant - all of which will produce 300 MW for much longer that the 6 hours per day this will do.

Until someone manages to drag the cost down to something sane (under $2000 per Kw would be nice), PV is a big hole where you can drop money in and not hear it hit the bottom.

But you're right, PV does help global warming. It's emission free power generation (no CO2 = no global warming), and has the advantage that it normally works when we do (ie, during the day). Plus it's made from the spongy white tissue on the inside of the rind of citrus fruit, so we all get the benefit. :)

[benburch]

5. PV is a fool's El Dorado.

Useful for off grid, but the real answer is solar thermal!

Big steel mirrors. Boil water. Drive a turbine.

Now, how do you handle night?

You superheat enough water that you can pull steam from it during hours of darkness!

There have been plants like this built for over 100 years. But cheap oil meant that their maintenance costs overcame the free "fuel". Clearly, that has changed now.

[Dead_Parrot]

8. Agreed...

A 300Mw Solar thermal plant could be built for a fraction of the cost, leaving you plenty to play with for storage solutions. Sadly, PV is cool and sexy, so it gets the funding. :(

[benburch]

10. Some info here

http://www.solardev.com/SEIA-makingelec.php

[Coastie for Truth]

6. PV is like a great big LCD screen with just a few big pixels

variously is series and parallel to optimize current and voltage.

(I am talking about amorphous-Si and micro-crystalline-Si thin film cells made by plasma CVD).

The fab technology is also approximately described by Moore's Law. (The cost per square unit is aproximately halved every 18-24 months).