Solar Energy is going to take over. There I said it.

Ceepea

Ceepea

Well-Known Member
If a large array of these were setup in unused places, like the Sahara, etc., we could utilize vast amounts of solar energy.



This plant doesn't use PV cells, it focuses solar energy on heat tubes filled with molten sodium, then pumps the liquid into giant holding tanks that will stay hot for 15 hours (powering 25,000 homes). Imagine, if instead of just heating tubes, they used a more advanced version of those new cells.... 20m x20m, is 400m2.

At 50W/cm2 that's 500kW/m2 x 400m2 is 200,000,000W on average..... not too shabby.

If that small dish converts 25kW of solar energy into electricity @ 50W/cm2 it would only take 500cm2.... tiny.

Re-checked the source, ibm.com, and it states 50W/cm2 not 200-250W like the other site.... I'd take the word of IBM over a repost.... regardless, the potential energy conversion is quite astounding.
 
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Red1966

Red1966

Well-Known Member
Solar energy reaching the Earth is only about 100 watts per square foot. The claims for this new cell seem unrealistic.
 
heckler73

heckler73

Well-Known Member
Ceepea,
You're forgetting one thing in your Saharan experiment, transmission.

And that's good you found the correction on the electrical generation, because I was going to ask about that. ;)
I thought about it after watching the vid and reading the egypt site, how much of the 0.8 is actually solar to electric? One needs to be careful with these numbers.
Anyway, the 200-250W is probably correct, but a large part of that is thermal energy.

BTW the trick I was taught, when I was in highschool physics, to remember the conversion of Watts and Horsepower was to envision a tug of war between a 747 Jet and a Horse. 747-1=746 [W/HP].

Red1966 said:
Solar energy reaching the Earth is only about 100 watts per square foot. The claims for this new cell seem unrealistic.
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Uhh, you do understand how parabolic dishes magnify incoming electromagnetic energy, right? How man square feet are in a circle with a diameter of 1m?
~0.785m^2 = 8.45 ft^2
8.45*100W/ft^2 = 845 W

And that's a crude, back of the dirty napkin, linear calcoomuhlayshun' there! I'm not factoring in any special laws of optics (mostly because I'm too lazy to look it up). Once you divide by the area of the receiver, you get the magic numbers. HOORAY! I HAS THE DUMB!
 
Ceepea

Ceepea

Well-Known Member
heckler73 said:
Ceepea,
You're forgetting one thing in your Saharan experiment, transmission.
Click to expand...


Arizona? lol There are lots of unused spaces in less than hospitable areas.

And that's good you found the correction on the electrical generation, because I was going to ask about that. ;)
I thought about it after watching the vid and reading the egypt site, how much of the 0.8 is actually solar to electric? One needs to be careful with these numbers.
Anyway, the 200-250W is probably correct, but a large part of that is thermal energy.
Click to expand...
Which can be used to desalinate water, or generate electricity.

BTW the trick I was taught, when I was in highschool physics, to remember the conversion of Watts and Horsepower was to envision a tug of war between a 747 Jet and a Horse. 747-1=746 [W/HP].


Uhh, you do understand how parabolic dishes magnify incoming electromagnetic energy, right? How man square feet are in a circle with a diameter of 1m?
~0.785m^2 = 8.45 ft^2
8.45*100W/ft^2 = 845 W

And that's a crude, back of the dirty napkin, linear calcoomuhlayshun' there! I'm not factoring in any special laws of optics (mostly because I'm too lazy to look it up). Once you divide by the area of the receiver, you get the magic numbers. HOORAY! I HAS THE DUMB!
Click to expand...
lol.... :)
 
Red1966

Red1966

Well-Known Member
So you would have to count the size of your reflector as the area, not the size of the cell. As I thought, their claims are unrealistic. A 747 has thousands of horsepower, not 747.
 
heckler73

heckler73

Well-Known Member
Ceepea said:
Arizona? lol There are lots of unused spaces in less than hospitable areas.
Click to expand...
Sure, I'm not arguing that. But when you start talking about odd places where the energy is not directly needed, one needs to consider the associated problems;transmission, conversion, storage.
Which can be used to desalinate water, or generate electricity.
Click to expand...
At what scale? Again, like micro and macro economics, translation from a small scale experiment to a large scale commercial application is not necessarily a linear relationship.
lol.... :)
Click to expand...
Ya liked that? Look at the follow-up:
Red1966 said:
So you would have to count the size of your reflector as the area, not the size of the cell. As I thought, their claims are unrealistic. A 747 has thousands of horsepower, not 747.
Click to expand...
It's good to know the obvious doesn't escape your keen perception, regardless of its relevance.
And yes, the size of the reflector including focal distance (based on radial dimension of a sphere) are critical in efficient conversion of energy. But the final numbers are determined by the size of the receiver. Hence if we took your hypothetical 100W/ft^2 and focused it with that 1m dish onto a 3cm^2 receiver, it would translate into ~280W/cm^2. So the numbers are not outrageous.
 
heckler73

heckler73

Well-Known Member
NoDrama said:
It is actually 1000 watts per Sq Meter. That's without being focused.
Click to expand...
That's not quite accurate (~1366W for TSI), and it still translates into ~127W/ft^2
1m^2 = ~10.7ft^2
So for the sake of illustration, Red's numbers are acceptable. That's assuming you aren't factoring in latitude or cloud cover, etc.
 
Red1966

Red1966

Well-Known Member
100 watts/sqft is the first number I saw when I looked it up. 1000 watts per m2 is over 10 times the area, so our numbers are about the same. He's claiming 250 a square centimeter, about 1/4 a square INCH. Not possible. Using mirrors or lenses to increase the concentration of solar energy doesn't change the area you still need to obtain a given amount of energy. I used to think windmills were going to be the next big thing, until I saw how many birds it kills.
 
Red1966

Red1966

Well-Known Member
You should also take into account that TSI includes diffuse radiation, about 1/3 of it. Diffuse radiation can not be focused with mirrors or lenses. Altho I have seen a design that attempted to do so, with some success.
 
heckler73

heckler73

Well-Known Member
Red1966 said:
100 watts/sqft is the first number I saw when I looked it up. 1000 watts per m2 is over 10 times the area, so our numbers are about the same. He's claiming 250 a square centimeter, about 1/4 a square INCH. Not possible. Using mirrors or lenses to increase the concentration of solar energy doesn't change the area you still need to obtain a given amount of energy. I used to think windmills were going to be the next big thing, until I saw how many birds it kills.
Click to expand...
Okay... I am going to take you to level II of understanding this. Don't make me take you to level III...you don't want to go there. I will crush you with Stokes' and Divergence theorems.
I may even hurt myself in the process, so let's hope you can grasp this after watching the following short video:
Pay attention to the math starting at 1:44...
 
Red1966

Red1966

Well-Known Member
You are disregarding that you'll still need just as large an area regardless of this cell, lenses, mirrors, or whatever. 250w/c2 doesn't fall on the surface, so it's not possible to extract it. Your example used a 2m^2 collector, not one the size of the pan the popcorn is in.
 
killemsoftly

killemsoftly

Well-Known Member
Ceepea said:
Did you read the article before posting?
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Red doesn't like to fill his head with useless facts. He subscribes to simplistic world views and follow his infantile feelings of anger.
Don't mind red, he wasn't breast fed as a child.
Sorry red, you do make this too easy. lol
 
Red1966

Red1966

Well-Known Member
Wow, you got a serious case of butthurt there. You going to follow me around to every forum and whine like a little bitch?
 
Doer

Doer

Well-Known Member
Ceepea said:
Torque not HP for plowing.
Click to expand...
OK. Big motorcycle guy here. Reworked a brand new T-Bird, that I'm on today.

TQ and HP are the same thing, looked at from different angles but I do agree that TQ is the side you are after for plowing.

And for my pickle, two big cylinders is the way to get big low torque.

Only Power applies Torque. Kilowatts to Newton meters is how I go faster, faster.

HP was standardized to Kw long ago.

How may horses pull the same?

Answer: None. :)
 
Ceepea

Ceepea

Well-Known Member
Doer said:
OK. Big motorcycle guy here. Reworked a brand new T-Bird, that I'm on today.

TQ and HP are the same thing, looked at from different angles but I do agree that TQ is the side you are after for plowing.
Click to expand...
Aye, HP is basically RPM x torque....

And for my pickle, two big cylinders is the way to get big low torque.

Only Power applies Torque. Kilowatts to Newton meters is how I go faster, faster.

HP was standardized to Kw long ago.

How may horses pull the same?

Answer: None. :)
Click to expand...
One needs look no further than a tractor for low HP machines that can move 'mountains'.... lol
 
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